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Tips - Introduction  

Welcome to Klausz Dental Laboratories Tips Section

 

Welcome to our complimentary listing of articles that will provide you with useful tips and tricks to benefit your practice. We hope you enjoy them. Articles are being updated on a regular basis, so bookmark this page and please visit again!

1. Overcoming Complete Denture Pitfalls
2. Temporization Tips for Today's Advanced Aesthetic Restorations
3. The Aqualizer, Is It Magic or Myth?
4. Hiding Denture Clasps: A Cosmetic Dilemma -- Stephen H. Abrams, DDS
5. Aesthetic Implant Abutments
6. Quality of Life Regained: Utilizing An Implant Supported Bar Overdenture: A Case Report
7. Five Techniques to Make Implant Treatment Easier, More Predictable, and Save Chair Time
8. Advanced Dental Occlusion - A Simplified Approach That Yields Maximum Results
tips intro
Tips - Overcoming Denture Pitfalls

Overcoming Complete Denture Pitfalls

From clinical considerations, to patient's expectations, the complete denture rehabilitation is full of pitfalls. The clinical aspects of complete dentures are notoriously known in modern dentistry as one of the most time consuming and least productive uses of time management. The concept of replacing all of the teeth, lost bone and tissue support from one or both arches has many areas where conflicts can arise.

Over the last thirty years, we have developed and perfected our own technique that has greatly enhanced the success of our clients' complete denture cases. We call it our "Modified Denture Technique". With this technique, we utilize the patient's existing complete dentures as a guide to the fabrication of their new dentures. Most complete denture wearers already have an existing set of dentures that they are wearing and are used to. They have come to acknowledge the tooth shade, shape and positions as being comforting. Any dramatic changes are usually seen as objectionable. It's almost like the feeling of replacing an old pair of shoes. You know it's time for a change as the old ones are worn out and unappealing. It's just that the new ones don't seem quite right. It's not that the new ones aren't better, it's they are just different. The concept of the denture technique stems from creating new dentures that improve fit, function and aesthetics, while at the same time maintaining as many similarit ies to the old set of dentures as possible. The procedure, as an added bonus requires less appointments and provides for a reduced laboratory fee, as the need for custom trays and bite blocks are eliminated.

We start by accessing why the patient requires a new denture i.e. loss of function, fit or aesthetics and determine what it is we are trying to achieve with the new dentures. With this in mind, we are ready to proceed.

The denture bases are assessed and prepared for a typical reline impression. Any gross undercuts on the tissue surface of the acrylic base are removed. If areas of the flanges need to be lengthened to extend the reach of the acrylic into tissue undercuts, border-molding compound needs to be applied. In most cases the flange length has been comfortable to the patient and any lengthening can result in sore areas and discomfort, so try to minimize the lengthening of the flanges if at all possible.

The next step involves taking a wash reline inside the denture . Depending on the amount of space inside the denture, a light or medium bodied impression material should be used to fill the void between the acrylic and the tissues. The original denture acts as the custom tray for all intents and purposes. (Figure 1) Once the impressions are done, it's time to establish the bite and determine if the vertical dimension needs adjusting to allow for the proper amount of freeway space as well as restore any lost facial characteristics.

With the reline impressions now complete, it is time to check the accuracy of the vertical dimension of the existing dentures. With the patient sitting up straight with his oral muscles in a relaxed state, measure the distance between two points on the patient's face; for example, the base of the nose and a mark on the chin, (Figure 2) while the patient is producing a "mmmmm" sound . This will approximate the vertical dimension that the patient requires for adequate freeway space. Now, have the patient occlude with the dentures in place and measure the distance once again. From the differences in these two measurements we can determine if and by how much the new dentures will be required to open the bite. This information can easily be related to the laboratory on the prescription. A centric occlusion bite is now done with a semi-rigid bite material using the closed mouth bite technique . This technique has the patient occlude his teeth together and once the relationship has been confirmed, bite material is injected onto the labial and buccal areas of the teeth. Once the bite material has set, the two dentures and the bite registration material are removed from the mouth in one piece and sent to the laboratory with instructions. (Figure 3)

In the lab, both arch impressions are poured and mounted onto an articulator with an anterior pin. A silicone or wax matrix is made that records the upper anterior tooth position in relation to the lower arch, i.e. midline, overbite, and over jet. Prior to the tooth set-up, any changes that the restorative dentist has noted on the prescription are taken into consideration. This could be in relation to increasing the vertical dimension, changing the shade of the denture teeth, etc. The dentures are removed from the mounting on the articulator and tooth selection is done usually to match a similar mould, size and shade to the patient's existing dentures. The original dentures are cleaned and returned to the dental office, usually on the same day. To enhance the fit of the old dentures while the new dentures are being made, a temporary, chair-side soft liner can be placed. To speed up the process, the patient can bring his impressions to the lab and wait for them to be given back. This is done so the patients don't have to go without their teeth for a long period of time. The in-lab procedures usually only takes a few hours.

In the lab, the teeth are set up in wax and are returned several days later to the office for a try in. Once the set up has been approved, final processing, trimming and polishing is done, and the completed dentures are ready for insertion. (Figure 4)

In most cases, only one try in appointment is needed and patient acceptance is easier to obtain since the new dentures have many similarities to the original pair. Most of the modifications are also easier for the patient to accept, as they will seem only minor, however they will most likely greatly enhance the fit, function and overall aesthetics for the patient. This technique can also be used when replacing only one complete denture in either of the arches, opposing natural dentition or an arch, which has a partial denture, as long as a mould of the opposing arch is also taken and sent to the lab.

Replacing worn, complete dentures does not have to be a complex procedure, providing that we make use of the information provided to us from the patient's original dentures.

Pound, Earl, DDS. Personalized Denture Procedures: Dentist manual: Anaheim, California, USA: Denar Corp. 1973: pg 67
ii Ivoclar OPA Ruler Guidelines, Ivoclar North America Inc., 1991
iii Heinenberg, Bernd-Jorg. Ivoclar Prosthetic Systems Manual, Ivoclar AG, Shaan/Liechenstein, 1990; pg 70

Ron Klausz, R.D.T. is owner of Klausz Dental Laboratories, located in North York, Ontario. A second generation registered dental technologist, he has chosen to follow in his father's footsteps. He keeps with the family traditions of producing advanced, high quality restorations while developing unique client and patient care services. He has modernized a company, whose focus is still based on fulfilling client needs. "Working harder and smarter for your practice!" is their credo.

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Tips - Temporization

Temporization Tips for Today's Advanced Aesthetic Restorations

As seen in "Doctor of Dentistry Magazine", January 2001.

When temporizing for today's less invasive, more cosmetic restorations, new twists need to be placed on proven techniques. Placing smaller temporary restorations with conventional means usually results in the premature loss of the provisional, leading to problems that can compromise your final results.

With more aesthetic options available to both the clinician and the patient than ever before, one area that is often overlooked in clinical discussions is how to temporize the prepared teeth while the final, permanent cosmetic restorations are being created at the laboratory.

In the case of anterior laminate veneers, many patients may only proceed with treatment contingent on the assurance that their teeth would not remain unsightly between the preparation and final cementation appointments (figure 1). With this in mind, several techniques have been developed to ensure the patient's concerns are addressed. One technique advocates bonding to only a small portion of the enamel, usually in the middle of the prepared tooth. This etched area should be approximately 3mm in diameter.

After the impressions and bite record are taken, the teeth should be first washed and disinfected with a .2% chlorhexidine solution and any areas of exposed dentin sealed with a bonding agent (it is advisable to use an older generation bonding agent, as many of the newer materials also contain a primer and will create too aggressive a bond). The bonding agent will also help reduce the incidence of post-operative sensitivity.

The selected areas in the centre of the prepared teeth can now be etched with a 35% phosphoric acid gel (figure 2). A small amount of bonding agent is placed only on this area. The temporary veneers can now be built-up, contoured with diamonds, and polished with disks directly on the tooth. One can consider using a temporary acrylic or a base of light cured temporary material. For even greater security, your material of choice can be added to the interproximal areas to help lock the temporary veneers in place.

There are two key items to consider when temporizing for veneers. Firstly, the gingival marginal areas of the temporaries must be accurate, smooth, and highly polished. This will prevent plaque from accumulating which can cause the gingival tissues to retract, thus exposing a slightly subgingival margin or a discoloured root surface. The second area of concern is the occlusion. There should not be any occlusal loading on the prepared teeth or on the incisal surfaces of the provisionals. Improper occlusal contacts can lead to a bond failure resulting in the loss of the temporary veneer.

A modification of the aforementioned technique involves the use of a diagnostic mock-up. Upon approval of a diagnostic wax-up, a thin, clear plastic stent can be made (figure 3). The stent has two distinct advantages, by trying in the stent over the prepared teeth, the clinician can assess if enough labial or incisal reduction has been done for the laboratory to achieve the desired cosmetic result. Also, the stent can act as a matrix for the fabrication of temporaries. The stent can be filled with your choice of temporary restorative material and placed onto the prepared teeth. Auto-polymerizing materials will set in place while light curing can be achieved though the stent's plastic matrix.

Using either method, the temporary material can easily be removed at the insertion appointment, using an interproximal carver.

Not only do these techniques provide an aesthetic provisional, but they also help to prevent tooth sensitivity and in cases of prior orthodontic treatment, they can prevent teeth from relapsing while the final restorations are being fabricated.

Another area of concern comes from the temporization of inlay/onlay preparations. With the trend towards less tooth reduction and more conservative prep designs and the advances in polymer glass materials, there is a greater need for adequate inlay/onlay temporization (figure 4). Most of the same principles that apply to veneer provisionals will also apply here. After the teeth are prepped and the impression done, an adequate temporary will prevent the drifting or over-eruption of teeth, which leads to heavy mesial and distal contacts and/or high bites. Both of these will result in the clinician having to make undesirable adjustments to the restorations.

The use of an antibacterial agent with fluoride can be used to clean the preps. Once again a bonding agent is applied, and again, it is advisable to use an older generation bonding agent, as the newer ones may contain primer. The same procedure can be applied when making larger inlays that fill pulp chambers (figure 5). It is advisable to fill any canals with cotton before the bond material is applied to prevent your bonding agent or temporary material from filling and blocking the canals.

The choice of temporary cement if required is also important. Zinc oxide eugenol cements may leave behind residual eugenol on the tooth surface after removal. The eugenol will interfere with cementation and also soften any resin present in the cement. Non-eugenol temporary cements are best and ones with low bond strength are advisable to facilitate easy removal of the temporary restoration.

With this article, it was my intention to provide you with more options when it comes to the temporization of today's more advanced yet less invasive restorations.

I would like to gratefully acknowledge the help and guidance I received in writing this article from my colleges, Dr. Stephen Abrams of Scarborough and Dr. Joe Bulger of Etobicoke.

Ron Klausz, R.D.T. is owner of Klausz Dental Laboratories, located in North York, Ontario. A second generation registered dental technologist, he has chosen to follow in his father's footsteps. He keeps with the family traditions of producing advanced, high quality restorations while developing unique client and patient care services. He has modernized a company, whose focus is still based on fulfilling client needs. "Working harder and smarter for your practice!" is their credo.

Abrams, S. H., A Technique for Temporization of Teeth during the Fabrication of Porcelain Veneers. Oral Health, 1996, November, pages 11 - 16

veneer prep spot etch resin stent onlay prep onlay prep
Veneer prep
Spot etch (3mm)
Resin stent in place
Typical onlay prep
Inlay prep into pulp chamber
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Tips - The Aqualizer

The Aqualizer, Is It Magic or Myth?

Dentistry is full of devices that promise more but deliver less. For every therapy that is founded in good science and reasonable practice, you might call it "evidence based", there are countless others that are endorsed and sold for a great deal of money and whose usefulness is very suspect.

Therapies for TMD are probably the most vulnerable to this kind of quackery. Patients with TMJ symptoms are usually frustrated beyond belief with the pain they are experiencing that they carry that frustration to the dentist whose care they seek. For the most part, the pain that these patients have is difficult to diagnose and even more difficult to treat. This is because it is near impossible to diagnose them whilst they are in pain, and certainly impossible to break that cycle.

Fortunately, a prosthodontist at the University of Illinois came up with a simple device consisting of two water pads, connected by an equalizing channel. The device is called Aqualizer™ When placed in the mouth, the effect is to allow both left and right sides of the molar segments to equilibrate with each other, putting the muscles of mastication in repose. Because the water pad separates the teeth, whatever prematurities existed in the occlusion have been eliminated for the time being. Muscle spasm is eliminated by the occlusal-muscular harmony. As this continues over a long period of time the muscles heal themselves.

The occlusal disharmony must be dealt with. The manufacturers of this device offer a three page recipe for doing so with the Aqualizer™. Obviously, occlusal disharmony can only be dealt with in one fashion, equilibration.

If disharmonies are simple, then their recipe works. However, most TMD patients do not deliver simple problems. This is the point where a high quality, fully adjustable articulator, such as the KaVo Protar comes into play.

The casts must be mounted to the articulator. Minimal records that must be taken are facebow, lateral checkbites and a true centric relation record. Again, the Aqualizer™ is a wonderful tool for preparing the patient for taking this record. A CR can only be taken faithfully when the muscles are at rest and the existing occlusion is not guiding the record taking. Dr. Dawson's method of "…romancing the bone…" is as effective as any other in guiding the mandible to a CR, but it can only work when the muscles are not in spasm. The insertion of an Aqualizer™ 10-15 minutes prior to record taking accomplishes that end. This process is called deprogramming.

Once the records are taken, the case mounted and articulator programmed, a definitive splint can be constructed and properly equilibrated on the articulator. This type of splint, can be worn by the patient for up to three months. When the patient is no longer symptomatic, the records must be repeated on the patient, case remounted and equilibrated on the articulator. The location and extent of equilibration can now be marked on the casts with colour coding. The colour-coded locations can now be transferred to the mouth. The technique is available on video tape.

The Aqualizer™ is an inexpensive, interim therapeutic device for both the straightforward and troublesome patient with TMD. It is also a useful adjunct for record taking in major restorative work, assuring the practitioner of a good and predictable result.

aqualizer device
insertion of aqualizer
Aqualizer in Place
Aqualizer in place
Aqualizer Device
Insertion of Aqualizer
Aqualizer in Place - Frontal
Aqualizer in Place - Sideview
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Tips - Hiding Denture Clasps

Hiding Denture Clasps: A Cosmetic Dilemma
Stephen H. Abrams, DDS

Partial dentures, at times, are a forgotten alternative in replacing missing teeth. Their one major esthetic failing is the need to use clasps for direct retention. Clasps require at least 180° encirclement of the tooth to act as an active retainer. This means that the clasp arm may be displayed on the buccal surface of the tooth and be visible in the smile. There is an ongoing struggle to provide direct retention in the anterior area without the display of any clasp arm.

There are a number of alternative clasp designs. Mesiodistal grip clasps engage only the mesial and distal surfaces of the tooth. They rely upon sound enamel surfaces and long guiding planes. The Equipoise Clasp relies upon a mesial guide plane with clasp extending around to the distal surface. The RLS lingually retained clasp for distal extension partial dentures which consists of mesio-occlusal rest a distolingual "L" bar and distobuccal stabilizer. Dual path or rotational path of insertion involves rigid retentive components and the initial placement of one segment with the denture being fully seated by rotating the denture into place. These are just a few of the approaches to dealing with esthetics and retention in partial denture fabrication.

Over the last fifteen years we have utilized the "Modified Hidden Clasp" for clasping anterior teeth. This clasp has been used in conjunction with circumferential clasps on posterior teeth, mesio-distal grip clasp, and guide plane retention. A Modified Hidden Clasp contains an occlusal rest and guide plane along with a bracing arm that engages an undercut on the tooth surface opposite the guide plane.

The literature describes some of the cosmetic challenges to restoring an anterior edentulous space. Some of the solutions offered are to avoid anterior clasping and utilize guide plane retention or utilize the anterior soft tissue undercuts. The Hidden Clasp is an ideal clasp for restoring Kennedy Class IV edentulous spaces. In photographs 1 and 2 we have used the clasp on tooth 23 to provide an active retainer for the anterior edentulous space. The bracing arm emerges from the distal rest and engages a mesial undercut. The distal guide plane just breaks through the contact area to provide stabilizing action. Additional retention is achieved using circumferential clasps on teeth 17, 14, and 25 along with rests on teeth 27 and 12.

The partial denture provided the patient with a very retentive esthetic restoration. The clasp on the posterior tooth was only visible with the cheeks retracted. The patient did not report any movement of the anterior section on chewing and no episodes of denture dislodgement. There was no evidence of caries or periodontal breakdown around the abutment teeth and this denture was replaced eight years later because of worn anterior denture teeth.

Hidden clasps can also be utilized for restoring Kennedy Class II edentulous spaces. In these situations, we find that the clasp is extremely retentive. Tooth 23 has a hidden clasp. There is a mesial guide plane with a bracing arm that extends around the lingual aspect of the tooth to engage the distobuccal undercut. The mesial guide plane extends into the contact area between teeth 22 and 23 but does not break the contact point. The guide plane is prepared so that we created a long parallel surface. In theory and in practice we have found that this does not create any additional torque on the tooth. The elements of this clasp eliminate any horizontal or vertical stress on the tooth.

We have also placed a distal guide plane and rest between tooth 13 and 14 to provide some additional cross-arch stabilization. We were concerned about the long term prognosis of tooth 14 and wanted to ensure that there was denture framework in the area in case we needed to add to extract this tooth.

Restoring a number of small edentulous anterior spaces introduces additional concerns. In these situations, not only is clasp position a concern but the need to match shape and contour of natural teeth to the denture becomes a significant factor . We needed to design a prosthesis that would replace teeth 12 and 21 but also allow for the addition of tooth 11 to the denture if needed. Tooth 11 was periodontal involved with M1 mobility, 4 mm of gingival recession and 2 mm. pocketing. We needed to utilize the tooth to provide an anterior occlusal stop but not be actively involved in retention. A hidden clasp was placed on tooth 13 with circumferential clasps placed on teeth 15, 25 and 26. A rest was placed on tooth 17 in case there was need to extract this tooth later on.

Composite veneers were placed on teeth 11 and 22 to allow us to create a uniform anterior shade. The anterior teeth were set on the ridge with no flange and anchored to the framework with small vertical retentive loops.

Photographs 10 and 11 show the teeth and partial denture at ten years. During this time there was no further breakdown of any of the abutment teeth or need to replace the composite veneers

Partial dentures do present a number of unique challenges in creating an esthetic restoration. One of the major challenges is to create anterior retention without the display of any retentive element. The literature provides us with a number of techniques for designing retainers. Modified Hidden Clasps provides one solution for the placement of clasps on anterior teeth. Their design allows for a guide plane to reciprocate an undercut on the opposite tooth surface. This clasp design is both retentive and does not place any additional stress or torque on the abutment tooth. These clasps along with other retentive elements should provide patients with a functional and esthetic restoration.

Acknowledgements:
I would like to acknowledge the help and advice of Mr. Ron Klausz of Klausz Dental Laboratories Toronto Ontario. Mr. Klausz has always provided interesting and innovative advice. He has introduced me to a number of interesting materials including the Hidden Clasp. My partner, Dr. Warren Hellen, has always provided a willing ear in treatment planning and case management.

Short Biography:
Dr. Stephen Abrams:

Dr. Abrams along with his partner, Dr. Warren Hellen, established a group practice in Scarborough, Ontario twenty two years ago. He is a fellow of the Pierre Fauchard Academy and the Academy of Dentistry International and has published numerous articles in various international publications. Dr. Abrams was recently awarded the Barnabus Day Award from the Ontario Dental Association for 20 years of service to the dental profession. He has been involved in issues concerning access to dental care for those in need. Dr. Abrams is the founder of Four Cell Consulting, Toronto Ontario, Canada, which provides consulting services to dental companies in the area of new product development and promotions. He can be contacted at (416)-265-1400 or e mail; dr.abrams4cell@sympatico.ca

Disclosure: Dr. Abrams has no financial interest in any of the products or techniques mentioned.

1. Osbourne, J., Lammie, G. A., Partial dentures, Edition 4, Philadelphia, 1974, J. B. Lippincott Company.

2. Zarb, G. A., Bergman, B., Clayton, J. A., MacKay, H. F., "Prosthodontic Treatment for Partially Edentuluous Patients, St. Louis, 1978, The C. V. Mosby Company.

3. Goodman, J. J., "The Equipoise Removable Restoration, Trends Tech Comtemp. Dent. Lab., 1991, Volume 8, pages 45 - 52

4. Aviv, I., Ben-Ur, Z., Cardash, H. S., Fatael, H., "RLS - The Lingually retained clasp assembly for distal extension removable partial dentures", Quintessence International, 1990, Volume 21, # 3, page 221 - 223.

5. MacKay, H. F., Fenton, A. H., Zarb, G A., Cosmetics and Removable Partial Dentures, Ontario Dentist, 1978, Volume 55, # 3, pages 23 - 28.

6. Halberstam, S C., Renner, R. P., "The Rotational Path Removable Partial Denture: The Overlooked Alternative", Compend. Contin. Educ. Dent., 1993, Volume 14, # 4, pages 544 - 552.

7. Jacobson, T. E., "Satisfying esthetic demands with rotational path partial dentures", 1982, JADA, Volume 105, September, pages 460 - 465.

8. Zarb, G. A., MacKay, H. F., "Cosmetics and removable partial dentures - The Class IV partially edentulous patient", J. Prosthet. Dent., 1981, Volume 46, # 4 pages 360 - 368

9. Beaumont, A. J., "An overview of esthetics with removable partial dentures", Quintessence International, 2002, Volume 33, # 10, pages 747 - 755.

10. Goodman, J. J., "The Equipoise Removable Restoration, Trends Tech Comtemp. Dent. Lab., 1991, Volume 8, pages 45 - 52

11. Sykora, O., "Esthetic considerations in the construction of a removable partial denture", Quintessence International, 1994, Volume 25, # 11, pages 757 - 762

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Case 1
Palatal view of the partial denture framework on the model. Note the types and position of the clasps used for retention.


Buccal view of the framework on the model. The Hidden Clasp on tooth 23 has a distal guide plane with the bracing arm engaging the mesial undercut from the lingual aspect of the tooth


Buccal view of denture in place. The circumferential clasps on the bicuspids are visible only with the lips fully retracted. Their placement allows for easy removal of the partial denture.


Final smile with no clasps or denture framework visible in the smile.


Case 2
Palatal view of the partial denture showing the Hidden clasps on the left cuspid and interproximal slot and rest between the right cuspid and bicuspid.


Buccal view with the cheeks retracting. Note there only the clasp on the upper right second molar is visible.


Final smile with no clasps or denture framework visible.


Case 3
View of the teeth before commencing treatment.


Palatal view of the denture on the model. Note the Hidden Clasps placed on tooth 13 with cingulum rests on teeth 11 and 22 to provide additional retention and position the partial denture framework to allow for the possible extraction and addition of one or more anterior teeth.


Buccal view of the teeth ten years after restoration and placement of the prosthesis.


Buccal view of the smile ten years after the partial denture was placed.
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Tips - Esthetic Implant Abutments

Aesthetic Implant Abutments - Unscrambling The Abutment Puzzle

The use of dental implants is on the rise. As patients are becoming more educated in dental options, dentists are finding it necessary to offer more choices. With an increase in proficiency in implant placement via oral surgeons, periodontists, and skilled general dentists, the stigma of implants being too advanced and “experimental” is fading.

Since their introduction, dental implants have been constantly evolving. From the original Branemark design with its external hex fitting surface, to the introduction of the internal connection, advances in implant designs have been immense. As implant fixtures have changed, so to have the restorative options we have available. Today, we are no longer limited by the proximity of bone to achieve a highly aesthetic result, nor are we forced to accept less than ideal treatment outcomes. With preplanning and a willingness to explore the possibilities that are available, fixed implant cases can provide you and your patients with natural looking and functioning restorations.

Implant abutments have come a long way over the last twenty years. The first abutments that were made available by such companies as Nobel Biocare, and Corevent (now Zimmer Dental) were referred to as "stock abutments", and came only in predetermined heights, which provided very few options (Figures 1 & 2). They engaged the external or internal hexes of the implant fixture, which provided all the anti-rotational stability available. They were restricted to a predetermined number of collar heights, usually 1 to 6 millimeters, to allow the margin placement of the final crown to be at the tissue crestal area .The only methods of modification were that of pure subtraction. The titanium could only be cut and shaped with carbides, diamonds, and stones (Figure 3). It was very difficult, if not impossible to add to them. In instances where the emergence profiles needed to be expanded, to correct misangled implant fixture placement, or even to increase abutment length to support a cemented crown, clinicians were faced with compromised results.
esthetic abutments
Later, angled abutments were provided by implant manufacturers. However, their uses were restricted due to the limited number of predetermined angles that were available, usually 10 to 25 degrees (Figures 4 & 5). Often, due to implant placement, the hexes, be it internal or external, did not allow for the predetermined core angle to fall into the correct or desired alignment. Their modification once again could only be of a subtractive nature. They were however, a good step forward in the evolution of "stock abutments".
esthetic abutments
Over the years, many new advances to "stock abutments" have emerged. Recently, the idea of scalloping the collar 360 degrees around the abutment has been introduced (Figure 6). The abutment collars that are contoured below the margin allow space for soft tissue around the implant, without compromising strength or aesthetics. The concept allows for a ring of soft tissue to form around the abutment and be held in place, thus supporting the tissue and maintaining bone height. With less likelihood of gingival recession, the potential for metal to be exposed in later years is reduced. These abutments are available from Zimmer Dental in a variety of collar heights and angles and are easily shaped and prepared in the laboratory to provide for adequate results in many instances where a stock abutment is warranted (Figures 7, 8, & 9).
esthetic abutments
Another useful advancement has been the development of the stock Zirconia abutment, such as the Zireal Abutment from 3I (Implant Innovations) (Figure 10). It provides the benefits of creating a light coloured material at the subgingival margin area, thus preventing the "gray gum syndrome" commonly found with metal abutments. It also provides a more translucent core as a base for future all ceramic restorations (Figures 11 &12).
esthetic abutments

The latest concept to be introduced to premade "stock abutments" allows for much greater versatility in restorative options (Figure 13). The Ankylos system from Dentsply no longer relies on internal or external hexes for anti-rotational support. The internal fitting connection utilizes a "Morris Taper" or internal cone of less than 6 degrees. By forcing the abutment with it's corresponding positive taper into the implant’s negative taper, a solid seal is created, locking the abutment in place with the strength of a cold weld (Figure 14). Not only is the union strong, but also gap free, protecting against microbial colonization. As there are no hexes to engage, the straight or angled abutment can be placed in any 360-degree rotational position. Angled abutments can now be aligned precisely to their most beneficial position. The design of the implant fixture head, along with that of the abutments also encompasses the concept of maintaining "horizontal biological width" through built in platform switching (Figure 15).

esthetic abutments
Implant manufacturers have recognized limitations to "stock abutments" and developed the castable abutment. These are commonly referred to as UCLA Abutments, which refers to their place of development. These abutments are comprised of a machined fit gold alloy base which fits to the corresponding implant head combined with a plastic sleeve which can be cut, modified and added to with wax prior to casting (Figure 16). The UCLA Abutment was a giant leap forward in making more aesthetic and more retentive implant restorations. It allowed the clinician to customize for each implant and situation, the emergence profile, crown margin depth, and abutment angulations. Off angled implants and those placed in less than ideal positions, now could be restored with more certainty (Figures 17, 18, &19). The fact that the abutment, after being cast, was still all-metal was one of its major aesthetic drawbacks.
esthetic abutments
Today we have available a wider selection of custom components that allow us maximum flexibility in aesthetic situations regardless of implant manufacturer. CAD/CAM technology is reinventing the way we customize implant treatments. Procera CADDesign lets us customize abutments to match the needs of each individual patient (Figure 20). These abutments are available for both the Branemark and Replace Select implant lines and now can be made from titanium or sintered Zirconia. This technology allows us to create custom abutments to practically any angle, taper, finish line, height and width to create the most natural form and emergence profile. Providing the benefits of superior strength with a white tooth shade emerging from the gingiva, makes these custom Zirconia abutments an ideal choice for anterior reconstructions. Procera is not alone in the CAD/CAM field. Other implant manufactures such as 3I (Implant Innovations) are now utilizing computer technology to create their own custom abutments through their Encode Custom Abutment Line (Figure 21) to enhance their existing CAD/CAM restorations such as CamStructure Milled Titanium Bars.
esthetic abutments
In a situation where custom all-Zirconia abutments are not available, we still have other options that work equally well. They provide great strength, with the ability for more natural emergence profiles without the graying of the gums. We are able to take the gold based UCLA Abutments, that most implant companies provide, cast them to their ideal shape and contour for our situation, and then create the labial margin area by baking porcelain directly onto them (Figures 22 &23). With this technique we get the strength and fit of a machined metal abutment with the aesthetics of an all-ceramic abutment avoiding the unaesthetic graying of the gingival tissue (Figures 24 &25).
esthetic abutments
esthetic abutments
Using manufacturers recommended components of implant fixtures, restorative parts and screws also ensures you are protected with whatever warranties the implant companies provide. As the old saying goes, “The sweetness of the savings is long gone when the bitterness of a failure is left behind.”
Consider now the many options you have available the next time you are faced with an aesthetics situation involving implants. At times, the restorative options can seem overwhelming. By applying a more simplified approach to restorations and prosthetics, combining them with accurate mounted and equilibrated models, implant dentistry can be both enjoyable and profitable.
With greater educational opportunities available to dentists, laboratory technicians and to the general public at large, dental implants are quickly becoming one of the fastest growing areas of dentistry. The concept of conservative dentistry has definitely played a major role in the popularity of dental implants, especially when only replacing a single missing tooth. This combined with the maturing of the baby boomer generation and their relentless pursuit of youth and the ability to enjoy life has provided for an environment with many positive attributes.
The time has now come to explore and expand this area of dentistry. Find a mentor, or someone whom you can rely upon, and build your implant team of professionals. Start your learning today. The rewards and benefits to your practice will most certainly outweigh any costs.
I would like to graciously thank Dr. Stephen Abrams, Dr. Paul Jesin, Dr. Steven Rosenblat, and Dr. Michael Weinberg for providing the clinical photos and guidance for this article.  They have all been inspirational as mentors in our continued pursuit of excellence in implant dentistry.
Ron Klausz, R.D.T. is owner of Klausz Dental Laboratories, located in Toronto, Ontario. A second generation registered dental technologist, he has chosen to follow in his father’s footsteps. He keeps with the family traditions of producing advanced, high quality restorations and appliances while developing unique client and patient care services.  He has modernized a company, whose focus is still based on fulfilling client needs.“Working harder and smarter for your practice!” is their credo.
Ron Klausz The author wishes to express that he has no financial interest in any of the companies or products mentioned in this article. However, Klausz Dental Laboratories is certified as a Nobel Aesthetic Laboratory, a Zimmer Preferred Laboratory Member and a 3I Certified Laboratory.
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Tips - Quality of Life Regained - Bar Overdenture, Implant Supported

Quality of Life Regained - Utilizing An Implant Supported Bar Overdenture:
A Case Report

As dental implants are gaining in popularity as a viable addition to removable dentures, more and more dentists are recommending them as a treatment option to their patients. The aging population of “baby boomers” is seeking options that will meet function as well as aesthetics. They are insisting on medical therapies and treatments that will improve the quality of their lives.

When it comes to restoring the complete edentulous arch, the use of dental implants has dramatically added to the treatment choices of today’s patients. No longer does a person have to accept the prospects of floating, loose dentures that cause frustration and embarrassment. With dental implants, once again function can be regained. Mandibular overdentures anchored on 2 anterior implants provide significantly greater satisfaction, quality of life and better mastication than do conventional dentures in edentulous patients. A panel of experts from McGill University recently recommended that mandibular overdentures become the standard of care for edentulusim.

The bar over denture has become a standard treatment option when it comes to the restoring of edentulous arches. Depending on your treatment objectives and outcomes, there are many different types of bar designs that can be utilized to retain a denture. Bar designs range from simple hader bars with gold or nylon clips for dentures which will be tissue supported, all the way to primary structures with attachments for dentures which are implant supported (Figure 1, 2, & 3). The design chosen will depend on many factors including the number of implants that are placed, their location in the arch, as well as the amount of intra arch space that exists

quality
Anecdotal observations from dentists I have consulted with suggest that implants placed in the maxilla should not be left free standing to retain dentures, without cross arch stabilization. By placing attachments, such as Locator Abutments (Figure 4) or Ball Abutments into dentures without the cross arch stability of a full palate or distal palatal strap, bone loss can occur. This bone loss is not immediate, but will occur over time (Figure 6, 7, & 8). Bone loss around implant fixtures, in these situations, can be attributed to micro movement caused by the flexing of a horseshoe shaped denture (Figure 5). With poorer bone quality in the maxilla, it is advisable to splint these implants together when trying to minimize or remove palatal coverage in the final prosthesis. In the mandible, with its denser bone, the implants can be left as individuals and not splinted.
quality
In this clinical case, a standardized protocol for bar overdenture fabrication was followed. Four implants were placed strategically in the mandible and six implants were placed in the maxilla (Figures 9 & 10). Closed Tray Impression Copings were screwed to the implants and fixture level impressions were taken of both arches (Figures 11 & 12), from which two soft tissue models were poured.
quality
All the implants were placed subgingivally, thus allowing for the option of placing more implants in the future and fabricating fixed restorations. However, with the bar overdenture, this posed a concern for bar seating as well as the maintenance of hygiene. Ideally, when the treatment plan calls for bar overdentures, it is advisable to have the implant heads placed at or slightly above the gum line. As a result, abutments with varying collar heights were placed on the implants to bring the height of the implant/bar margins to the gingival crest (Figures 13 & 14).
quality

Bite blocks were fabricated, using 2 temporary cylinders luted to the base plate. By utilizing the temporary cylinders, the record base could be fastened to a few of the implants to give stability and ensured a more accurate bite registration was achieved.

To ensure the master model was accurate and to ensure the bar to be fabricated had a passive fit, an Implant Positioning Record (IPR) was made. Non-engaging temporary cylinders were placed onto each implant on the master model. They were weaved together with dental floss and finally covered over with pattern resin (a quick setting, low expansion acrylic)(Figures 15 & 16 On the next page).This index was taken to the mouth and placed onto the implants to ensure a passive fit (Figures 17 & 18 On the next page). If the index rocked or did not seat fully, it needed to be sectioned and looted together on the implants in the mouth. In the lab, a new set of fixture replicas (analogues) were secured to the temporary cylinders and a base was poured. Using this new model we ensured that the bar fitted passively as it represents an accurate positioning of the implants.

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After the bite registration was done and the IPR confirmed the accuracy of the master models, the models were mounted and the denture teeth were set up on the same screw retained record bases.  Once the ideal tooth position was established for aesthetics, function, and phonetics, and verified intra-orally at the try-in stage (Figure 19), the bar fabrication was started.
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Utilizing today's advanced CAD/CAM technologies, Biomet 3I's CAM StructSURE Precision Milled Hader Bars were fabricated.  Milled from a solid block of titanium alloy, these restorations are lightweight and provide a passive fit without the potential weakness associated with cutting and soldering.
 
After a detailed scanning of the master cast and overdenture tooth set-up, a proposed design was prepared for assessment (Figures 20, 21, 22, & 23). Consideration was given to the amount of space between the bars and soft tissue of the ridge, that adequate space was allotted for the female attachments inside the confines of the denture, as well as many other details that can affect the final outcome of the case. Once approved, the milling of the bar was completed and the finished, polished bars were verified for accuracy of the fit and of the design prior to sending the bars to the dentist's office for try-in (Figure 24).
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Once the fit of the bar was confirmed on the implants intra-orally, the case was sent back to the lab for final processing (Figure 25). A cast partial frame was fabricated in a horseshoe shape for the maxillary arch. The casting allowed for less palatal coverage as well as less weight and bulk while still maintaining strength. A cast mesh frame was made to reinforce and strengthen the mandibular denture. The acrylic was processed attaching the female, nylon clips in their correct place (Figures 26 & 27).
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The final case was inserted with the placement of the bars and the insertion of the overdentures (Figure 28). A great result was achieved leaving the patient with stable, aesthetic, functioning dentures.
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Today's patients take excellent aesthetics, form and function for granted, even for implant-based restorations. With today's advances in materials and technology a greater quality of life can be provided to the totally edentulous patient. The author wishes to gratefully acknowledge the help, support, and clinical photographs provided by Dr. Stephen Abrams, Dr. Michael Weinberg, and Dr. Stephen Zamon in the writing of this article.
picRon Klausz, R.D.T. is owner of Klausz Dental Laboratories, located in Toronto, Ontario. He has written numerous articles on restorative and implant dentistry and has lectured in both Canada and the United States. He keeps with the family traditions of producing advanced, high quality restorations and appliances while developing unique client and patient care services. He has modernized a company, whose focus is still based on fulfilling client needs. "Working harder and smarter for your practice!" is their credo.
i Boerrigter, EM, et al, "Patient satisfaction and chewing ability with implant retained mandibular overdentures: A Comparision with a new complete denture with or without preprosthetic surgery", J Oral Maxillofac. Surg., 1995; 53: 1167 - 1173
ii Heydecke, G., Locker, D, Awad, MA., Lund, JP, Feine, JS, "Oral and general health related quality of life with conventional and implant dentures", Community Dent. Oral Epidemiol., 2003; 31: 161 - 168
iii Feines, JS., Carlsson, GE., Awad Ma., et al "The McGill Consensus Statement on Overdentures. Mandibular Two-Implant Overdentures as First Choice Standard of Care for Edentulous Patients", Gerodontology, 2002: 19; 3 - 4
iv Heckmann SM, et al, Overdenture Attachment Selection and the Loading of Implant and Denture-bearing Area, Clin.Oral Implant Res. 2001: 12; 640-647
v Clelland et al, Fit Related Strain Around Implants. Journal of Prosthodontics,1995, 4 (4); 244-250
vi Chee W.,. Jivraj, S., Treatment Planning of the Edentulous Mandible, British Dental Journal, 2006: 201 (6); 337-338
vii.Galindo, F., The Implant Supported Milled-bar Mandibular Overdenture, Journal of Prosthodontics, 2001; 10 (1); 46-51
viii Burns, D., Mandibular Implant Overdenture Treatment: Consensus and Controversy, Journal of Prosthodontics, 2000: 9 (1;) 37-46
Aesthetics and function restored
Figure 28
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Tips - Five Implant Techniques

Five Techniques to Make Implant Treatment Easier,
More Predictable, and Save Chair TimeResults

The use of dental implants is becoming more prevalent in today’s dental practices. As patients are becoming more educated about dental options, dentists are finding it necessary to offer more choices. The aging population demographic of baby boomers are seeking options that will meet function as well as aesthetics. They are insisting on rehabilitation that will improve the quality of their lives. With an increase in proficiency in implant placement via oral surgeons, periodontists, and skilled general dentists, the stigma of implants being too advanced and “experimental” is fading.

Since their introduction, dental implants have been constantly evolving. From the original Branemark design with its external hex fitting surface, to the introduction of the internal connection, advances in implant designs have been immense. As implant fixtures have changed, so to have the restorative options we have available. Today, we are no longer limited by the proximity of bone to achieve a highly aesthetic result, nor are we forced to accept less than ideal treatment outcomes. With preplanning and a willingness to explore the possibilities that are available, implant cases can provide you and your patients with natural looking and functioning restorations.

With all these advancements, dentists and laboratory technicians must seek out techniques and materials that will improve the quality of these restorations while at the same time making the techniques easier, more predictable, and reduce chair time.

The Closed Tray Impression Technique for taking implant level impressions has become very popular over the years. Its simplified approach has given it the advantage over the other method of using an open tray procedure. The closed tray technique involves placing the implant transfer copings (also known as impression copings) onto the implant heads and taking an impression over the transfer copings that have been secured onto the implants.

Some of these impression copings have hexes or stars on their tops for the screwdrivers to engage (Figure 1). This enables the dentist to ensure the transfer copings are snug and secure. These openings, however, can lead to a situation where an inaccuracy can be incorporated into the overall impression technique.

Light bodied impression material will flow into these tiny areas leaving a positive interference in the bottom of the impression where the coping needs to reseat. This makes it impossible to reseat the impression copings fully. The result is a final restoration which is dramatically high in occlusion. The solution is to place orthodontic or boxing wax into these spaces on top of the implant transfer copings prior to taking the impression (Figure 2). By neatly filling the opening and not leaving gross amounts of wax on the impression coping heads, the impression copings will fully seat back into the impression. As an added benefit, that same wax can help organize the healing abutments as they are removed from the mouth (Figure 3).

 

5 techniques
Figure1 Figure 2 Figure 3

Implant abutments fabricated in the dental laboratory, whether stock or custom, need to be placed consistently in the same orientation. When the case is completed and sent to the dentist’s office for final insertion, this orientation needs to be transferred from the stone cast to the implant intra-orally. To do this, a “Custom Orientation Jig” should be fabricated. These jigs are made with low shrinkage, pattern resin. They should fit snugly around the core of the abutment and the lateral extensions should rest on the adjacent teeth. They can be placed on the abutment while it is still seated on the model and taken from the model to the mouth (Figures 4,5,6,7). By using a “Custom Orientation Jig”, you can be assured that the internal or external hexes of the implant and abutment will be aligned; as well, you will reduce the risk of damaging these hexes. As an added benefit, once the jig is fully seated on the adjacent teeth it acts as a double check that the abutment is fully seated on the implant fixture.

5 techniques
Figure 4 Figure 5 Figure 6 Figure 7

When a natural tooth is lost and an implant placed, there is usually some type of bone loss which causes the tissue in the papilla region to recede. This in turn creates a space below the natural contact areas of teeth (Figure 8). More prevalent in the posterior quadrants, these areas can’t be closed with the implant restoration as they fall into an undercut from the crown’s path of insertion (Figure 9). The best way to avoid creating these potential food traps is by adjusting the contact areas of the natural teeth prior to taking the implant fixture impression. By reducing the enamel from the height of contour, the gingival embrasure below the contact will decrease in size (Figure10). Looking for this potential problem at the onset can save quite a bit of time as well as discomfort for the patient.

  5 techniques 
Figure 8 Figure 9 Figure 10

When it comes to restoring the complete edentulous arch, the use of dental implants has dramatically added to the treatment choices of today’s patients. No longer does a person have to accept the prospects of floating, loose dentures that cause frustration and embarrassment. With dental implants, once again function can be regained.

The bar overdenture has become one of the optimal treatment options when it comes to the restoring of edentulous arches. Depending on your treatment objectives and outcomes, there are many different types of bar designs that can be utilized to retain a denture. The design chosen will depend on many factors including the number of implants that are placed, their location in the arch, as well as the amount of intra arch space that exists.

The simplest bar design is the common Hader Bar. The denture is held securely into place by incorporating clips into the denture base, which grab hold of the bar. These clips come in two main materials. The original clip designs are gold with little wing extension which are embedded into the acrylic and hold the clip in place (Figures 11 & 12). These wings are very small and have a tendency to break off. If this should happen the entire clip needs to be removed and replaced with a new one. The technique for replacing them intra-orally involves blocking out the space below the bar and using self curing acrylic. If done incorrectly, the acrylic can flow under the bar and lock the denture in place. The only option left to the practitioner is cutting apart the denture to remove it.

The creation of nylon retentive sleeves has become a great benefit. These sleeves lock into metal housing using mechanical retention that is built into their design (Figure 13). The metal housings are securely luted to the acrylic denture base (Figure 14). If the sleeve should break or lose its retentive properties over time, the clip is easily removed and a new clip will snap into the metal housing. The entire procedure takes only a few minutes with less stress for both the patient and the doctor.

5 techniques
Figure 11 Figure 12 Figure 13 Figure 14

The Locator Overdenture Attachment has become quite popular over the last number of years. Its versatility and ease of use has made it the attachment of choice for dentists and technicians alike. It was originally created to be used to retain full lower dentures over implants, but it has evolved to encompass many different case designs. The black processing male components have a built in spacer of about one quarter of a millimetre (Figure 15). This one quarter of a millimetre spacer holds the final male locator attachment slightly high above the female component on the implant abutment. This feature was developed to allow for a slight amount of settling of the final denture into the soft tissue that it rested upon.

If however, Locator Overdenture Attachments are being utilized on implant bars or in conjunction with tooth-born cast partial dentures, this spacer poses a significant problem. As this final prosthesis will not settle into place, the male locator attachment will remain above the female counterpart and there will not be any retention. To ensure this doesn’t occur, the manufacturer of the Locator Attachment, Zest Anchors, has developed another male processing sleeve. This sleeve is yellow in colour and was manufactured without the quarter of a millimetre spacer (Figure 15). When using this yellow processing male on a bar or in conjunction with a tooth born cast partial, the final male locator attachment will be processed in the exact final position that it needs to be in to provide the utmost in retention (Figure 16). Be sure to request the correct male processing sleeve to avoid complications at your final insert appointments.

5 techniques
Figure 15 Figure 16

Implant treatments can be an enjoyable and fulfilling adjunct to any successful dental practice. Techniques have been developed to save time and make these restorations more profitable. As with all things, there are always little tricks and techniques to utilize, and to watch out for, that can make all the difference. By utilizing some of these tips and perhaps some of your own, you can take a case that just works out, to a case that will provide an exceptional result for the patient, the dentist, and the laboratory technician.

The author wishes to gratefully acknowledge the help, support, and guidance provided by Dr. Michael Weinberg in the writing of this article.

Ronald Klausz, R.D.T. is owner of Klausz Dental Laboratories, located in Toronto, Ontario, Canada. In 1989 he graduated with honors from the Dental Technology Program, at George Brown College, in Toronto, and became a Registered Dental Technologist in 1990. He has written numerous articles on restorative and implant dentistry and has lectured in both Canada and the United States. A second generation registered dental technologist, he has chosen to follow in his father's footsteps. He continues the family traditions of producing advanced, high quality restorations while developing unique client and patient care services, specializing in occlusion, implants and cosmetic dentistry.

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Tips - ADVANCED DENTAL OCCLUSION

A Simplified Approach That Yields Maximum Results

The last decade has brought about dramatic changes in how we view and perceive beauty. There have been a variety of makeover shows such as “Extreme Makeover” that take average people and transform them into what society believes to be beautiful. Weekly, dramatic programmes such as “Nip/Tuck” make plastic surgery seem simple, painless, and instant. At the same time these types of shows exemplify the many benefits beauty can bring to one’s life. We have become a society obsessed with beauty.

When it comes to dental restorations, we look for nothing short of aesthetic perfection. The art and science behind the making of lifelike restorations has been obtained by most dental laboratories and clinicians. Beautiful and natural looking reproductions of teeth can be created with a variety of different techniques and materials.

So vast is the potential of the dental industry, that dental manufacturers have spent millions of dollars in the hopes of persuading you and I that their restorations and materials will look and function better than the rest. When in reality, applied with the knowledgeable skill and dedication of today’s technologists and clinicians, shape, shade, and texture can all be applied to create beautiful smiles with a wide variety of restorative materials.

The real question is how will these beautiful smiles we create today hold up to the rigors of mastication and occlusal forces? When fixed restorations break, removable appliances do not function properly, and splints fail to alleviate pain, do we immediately blame the material or do we choose to look deeper into ourselves? Do we dare question the process we use and search for a more predictable one?

One of the most overlooked and a misunderstood aspect in modern dentistry is the concept of “Occlusion”. In dental schools across the continent, occlusion was taught to be confusing, indefinable, and in terms that were difficult to memorize and easy to forget. With the movement over the past decade of “Cosmetic Dentistry” the concepts of occlusion were put on the back burner.

Today, many clinicians confident with their cosmetic successes, are now taking a closer look at “Occlusal Concepts” and seeking procedures that can provide for better function and long term clinical success. Teeth need to work and function in harmony with each other.1 They must provide for maximum interdigitation in function and working contacts.2 At the same time they must allow for the free range of motion provided by the reduction of interferences in movement.3,4

Simple solutions to complex procedures were developed to increase productivity as well as decrease costs. Plastic, disposable hinges (Figures 1 & 2) have provided for the simple mounting of casts together, however they do nothing to relate the dentition to the patient’s condyles or to the base of the skull, and thus provide none of the information needed to create free function. They are a simple and inexpensive alternative and they do have their place in straightforward one to two tooth reconstructions. However, they lack the necessary information that is needed to ensure interferences are not inadvertently built into our restorations. Unfortunately, with these types of articulators, corrections of occlusion are left to the restorative dentists to waste valuable chair time with adjustments and re-polishing of restorations.

In the past, there were many manufacturers who made attempts to resolve occlusal concerns. They created awkward articulators that were difficult to work with and complex facebow procedures which required additional assistance and cumbersome tools to use.5 Their attempts focused solely on the apparatus and provided for less than satisfactory results.

With greater research has come more accurate and efficient articulator systems. These advanced pieces of equipment allow for simpler procedures, making them more readily accepted by dentists, staff, and patients.6 The newer earbow style of facebows such as the Arcus by Kavo (Kavo Canada 1-800-324-6055/www.kavousa. com) effectively records the position of the upper jaw in relation to the individual’s hinge axis. With its simple design and ease of use, without the need for tools or additional assistance, the Arcus earbow can take less than two minutes to accurately record the maxilla position.

The procedure is straight forward. A bite fork is covered with bite registration material and inserted into the mouth having the patient close down gently to hold the fork in position while the bite registration material sets. A single operator now begins by first placing the earbow extensions into the patient’s ears (Figure 3). After gently closing the bow arms together, a single lever is raised to secure the position. Next, the anterior plunger arm is extended forwards to the glabella region of the nose (Figure 4). While applying pressure to the plunger arm another single lever is engaged. If enough pressure is applied, the earbow should be able to support itself on the patient’s face without the need for anyone to hold it (Figure 5). The final step is to connect the earbow with the bite fork using the bite fork assembly. Once again two simple thump screws are turned until tight, thus locking the pieces together (Figure 6). The earbow registration is now complete (Figure 7). All that remains is the removal of the apparatus from the patient’s face.

Articulators such as the Kavo Protar evo (Kavo Canada 1-800- 324-6055/www.kavousa.com) allow for greater accuracy and control (Figure 8). These types of semi-adjustable articulators can be programmed with information provided through the use of the earbow and various check bites to more accurately mimic the jaw movements. By providing such bite registrations as Centric Occlusion (Figure 9), Protrusive (Figure 10), Left and Right Lateral Check Bites (Figures 11 & 12), settings of the Condylar Inclination, the Bennett Angle, Side Shift, and Retrusion can be recorded (Figure 13). These measurements programmed into the articulator can also be recorded and stored for later use (Figure 14).

Recently introduced is the Kois Dento-Facial Analyzer System (Panadent Corporation 1-800-368-9777/www.panadent. com). This system measures the cant or tilts of the patient’s occlusal plane in three planes of space and transfers this information to the articulator. Based on Dr. Kois’7 research revealing an average axis-incisal edge distance of 100mm (Figure 15), this unique concept is supported by Bonwill’s Equilateral Triangle, Monson’s Spherical Theory,8 and Weinberg’s Studies.9,10,11 The Vertical Indicator Rod is aligned to the patient’s facial midline for aesthetics while the wall on the Index Tray is aligned to the central incisors to relate to an average 100mm axis-incisal distance for function. The procedure is simple. The Index Tray is secured to the Analyzer Bow, which resemble a Fox Plane. With bite registration material applied, the Index Tray is inserted much like a standard bite fork. After making sure the maxillary incisors contact the incisal line/wall marked on the Index Tray, align the vertical Rod to the patients mid-sagittal in the frontal plane (Figure 16) and adjust the Analyzer Bow to the horizontal in the sagittal plane from the profile view (Figure 17).

The main benefit of this system is that it is not based on the external soft tissue characteristics of the patient. It is not fooled into providing an inaccurate horizontal plane based on the unevenness of the patient’s ears or eyes.

Another unique and equally useful tool in the evaluation and diagnosis of dental occlusion is the Accu-Liner Instrument (Figure 18) (Accu-Liner Products 1-800-458-6627/www.acculiner. com). The name Accu-Liner refers to the accurate alignment and measurement of study models, dental prostheses, and restorations with reference to cranial landmarks and sagittal, transverse, and horizontal planes of the skull. Brought to the dental market place by Dr. James Carlson, the fabrication of the instrument came from his desire to precisely diagnose and treat occlusion. He wanted a scientific instrument that could provide accurate measurements which would aid in his ability to analyze and treat his patients.

The Accu-Liner does not require any condylar elements as it subscribes to the theory that border movements of the mandible do not occur during figure 20 function. Research has shown that the primary criteria for successful orthodontics, 12 fixed and removable prosthetics,13 or dental orthotics is the precise construction of the plane of occlusion and interdigitation of the teeth to the optimal neuromuscular position of the mandible.14

The Accu-Liner goes beyond any previous Class II articulator in that it is capable of closely simulating the individual movements of the tempromandibular joints: translation (vertical, horizontal, and lateral components) and rotation (Figure 19).15

The Accu-Liner is more than just an articulator. It is an instrument which allows you to register, analyze and treat the occlusion. It is designed around the widely accepted concept that the maxilla is the primary arch of the stomatognathic system,16 not the mandible. It relates the plane of occlusion to stable landmarks in the cranium using the anatomical reference points of the base of the skull and the Hamular Notches and the Incisive Papilla (HIP Plane) (Figure 20). By using these reference points, the Accu- Liner can measure, in millimeters, all movements of the mandible as well as distortions in the maxillary arch.

The success of a dental prosthesis or restoration has a direct correlation to the amount of precision that is utilised in the dental operatory and the dental laboratory. Which facebow or articulator system you choose can be based on your own requirements, beliefs, and comfort level. It is more important that you choose to advance your knowledge and skill with a particular system, and become proficient at it, than in which system you choose to work with. If you are interested in pursuing your options, you may wish to consult with your “lab technician”. He or she will have the experience to help guide you. With a greater choice in instrumentation than at any other time in dental history, today’s dental professionals can create highly functional restorations, appliances and orthotics. It is through these advances that we can look beyond what is just aesthetically pleasing and build greater function into the work we create. The net result is an increased satisfaction in our daily lives and the knowledge that we have provided our patients with optimal oral health to the best of our abilities.

The author wishes to gratefully acknowledge the help, support, and guidance provided by Dr. Stephen Abrams in the writing of this article.
Ron Klausz, R.D.T. is owner of Klausz Dental Laboratories, located in Toronto, Ontario. He has written numerous articles on restorative and implant dentistry and has lectured in both Canada and the United States. He keeps with the family traditions of producing advanced, high quality restorations and appliances while developing unique client and patient care services. He has modernized a company, whose focus is still based on fulfilling client needs. “Working harder and smarter for your practice!”
is their credo.
advanced occlusion
advanced occlusion
advanced occlusion
advanced occlusion
advanced occlusion


References:

1. Racich, M. J., “Orofacial pain and occlusion: Is there a link? An overview of current concepts and the clinical implications”, J Prosthet Dent., 2005; 93: 189 - 196

2. Davies, S. J., Gray, R. M. J., Whitehead, S. A., “Good occlusal practice in advanced restorative dentistry”, BDJ, 2001; 191: 421 - 434

3. Brill, N., Schubeler, S., Tryde, G., “Influence of occlusal patterns on movements of the mandible”, J. Prosthet. Dent, 1962; 12: 255 - 261

4. Davies, S. J., Gray, R. M. J., “What is Occlusion?” BDJ, 2001; 191: 235 - 245

5. Starcke E. N., “The History of Articulators; From Facebows to the Gnathograph, a Brief History of Early Devices Developed for Recording Condylar Movement: Part II”, J. Prosthodont, 2002; 11; 53 - 62

6. Becker, C. M., Kaiser, D. A., “Evolution of Occlusion and Occlusal Instruments”, J Prosthodontics, 1993; 2: 33 - 43

7. Kois, J. C., Unpublished Data

8. Monson G. B., “Occlusion as applied to crown and bridgework” J Nat Dent Assoc., 1920; 7: 339 - 413

9. Weinberg,L.A., “An Evaluation of the Face-Bow Mounting”, J Prosthet Dent 1961- Vol. 11, Num. 1; 32-40

10. Weinberg,L.A., “An Evaluation of Basic Articulators and Their Concepts- Part I”, J Prosthet Dent 1963- Vol. 13, Num. 4; 622-644

11. Weinberg,L.A., “An Evaluation of Basic Articulators and Their Concepts- Part II”, J Prosthet Dent 1963- Vol. 13, Num. 4; 645-663

12. Davies, S. J., Gray, R. M. J., Sandler, P. J., O’Brien K. D. O., “Orthodontics and Occlusion”, BDJ, 2001; 191: 539 - 549 13. Taylor, T., Wiens, J., Carr, A., “Evidence-based
Considerations for Removable Prosthodontics and Dental Implant Occlusion: A Literature Review”, J Prosthetic Dentistry, 2005; 94: 555 - 560

14. Davies S. J., Gray, R. M. J., McCord, J. F., “Good occlusal practice in removable prosthodontics”, BDJ, 2001; 191: 491 - 502

15. Carlson, J. E., “The AccuLiner System”, 3rd Ed. Midwest Press: 2005; iii

16. Carlson, J. E., “Physiologic Occlusion. 3rd Ed. Midwest Press; 2008
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