Reprint

CR is the original and only independent dental product testing organization with funding only from dentists!Reprinted April 2019, with permission, from Volume 12 Issue 1, January 2019, Pages 4–6

This official reprint may not be duplicated. This reprint is prepared for the purpose of providing dental clinicians with objective information about dental products. ©2019 CR Foundation®

A Publication of CR Foundation® • 3707 N. Canyon Rd, Bldg 7, Provo UT 84604 • 801-226-2121 • www.CliniciansReport.org

Complete Dentures can be Easier to Make and More SuccessfulGordon’s Clinical Observations: Few dentists enjoy making mandibular complete dentures, and even maxillary complete dentures often frustrate both dentists and patients. Why is this frustration present? Are there better ways to treat edentulism without resorting to the more expensive option—implant retention and support? Are dentists being taught complete denture techniques that are effective? Can most dentists make an adequate complete denture? CR clinicians and scientists have identified some of the reasons for denture failure and share their findings and suggestions with you in this article.

How large is the edentulous challenge in the USA? This number has been difficult to determine by most groups. Observe below the USA census and ADA estimates followed by CR calculations:

• Census estimates of adults in the USA are ~77% of 323,405,935 or ~249,747,123 adults.• Of the ~198,500 dentists in the USA about 80% are general

dentists or ~158,400 GPs.• A rough estimate of the patients in a typical American general

practice is ~1,500 patients or 1,155 adults.• Estimates for edentulism in the USA range from 35

million to 40 million people or 15–16 percent of adults. THAT ESTIMATE IS ABOUT 162 TO 185 POTENTIAL EDENTULOUS PATIENTS PER GP!

As shown in a CR survey, this large number of moderately to totally dissatisfied patients require our attention and immediate change. This article will help to remedy the situation.

Vertical dimension loss of 1.5 cm makes for a difficult denture, but the complete denture procedure can be simplified!

Why is treatment of edentulous patients so difficult? There are many reasons. Among them:

• There is minimal emphasis on edentulous patient treatment in most dental schools.

• Many techniques are time consuming and expensive.• Lack of delegating some of the steps to qualified educated staff.

• Lack of interaction with technicians.• Previous unsatisfied patient experiences make technique not

desirable.

Techniques and SuggestionsThe following techniques and suggestions provide proven concepts that simplify treatment and increase patient satisfaction. There are many other acceptable techniques and materials.

1. Diagnostic Appointment• Many practitioners could accomplish a more thorough diagnostic appointment, but they

are too busy doing treatment in order to produce revenue. Using educated staff to collect diagnostic data allows the dentist to be treating other patients while diagnostic data is being collected by qualified staff persons. The dentist does just the analysis of the data and a treatment plan proposal. The video Efficient Diagnostic Data Collection by Auxiliaries (V1136) by Practical Clinical Courses (PCC) shows this concept (pccdental.com).

• Provide complete informed consent to the patient telling them about all of the alternatives for their oral condition.

• Included in the auxiliary-oriented diagnostic data collection are border molded alginate impressions (Figure 1) allowing properly extended custom trays (Figure 2) to be made by staff or a dental laboratory.

• Time for diagnostic appointment: 70 minutes total, 60 minutes staff, 10 minutes dentist at end of appointment.

2. Appointment 1, Final ImpressionThis is the most frequently observed worst step in the denture procedure as observed in dental labs. If you are not satisfied with your impressions, please try the following procedure.• Final impression first step using custom made trays is border molded preliminary final impression (Figure 3 on following page) made in

heavy body polyether, or vinyl polysiloxane.

FIGURE 1

Dental staff must know how to make adequate border molded alginate impressions to allow an optimum

custom tray to be made

FIGURE 2

Triad by Dentsply Sirona

2Clinicians Report January 2019

Complete Dentures can be Easier to Make and More Successful (Continued from page 1)

Techniques and Suggestions (Continued)

2. Appointment 1, Final Impression (Continued)• Final impression second step is wash impression using

same elastomer as above in light viscosity polyether or vinyl polysiloxane. (Figure 4).

• Time: 30 minutes total, 20 minutes staff, 10 minutes dentist.3. Appointment 2, Centric Jaw Relation

• Laboratory or office staff make resin-based, impression material supported occlusion rim with wax on it (Figure 5).

• Vertical dimension of occlusion is determined by dentist and recorded in wax on occlusion rims (Figure 6).

• Smile line and midline are indicated on the occlusion rims.• Teeth mold and color are determined.• Time: 20 minutes total, 5 minutes staff, 15 minutes dentist.

4. Appointment 3, Try-in Tooth Wax-up• Try-in tooth wax-up that has been mounted on semi-adjustable

articulator (popular example Whipmix) (Figure 7). Have patient critique the potential esthetic result, if necessary, change tooth set-up, obtain patient approval, and finalize try-in.

• Time: 15 minutes total, 5 minutes staff, 10 minutes dentist.

5. Appointment 4, Seat Dentures• Dentures are tried in and fit is modified if necessary. Materials

used to fit denture: staff-made pressure indicator paste consisting of 1/2 by volume zinc-oxide and 1/2 by volume household Crisco oxygenated vegetable oil (Figure 8).

• For final pressure spots and post-dam adequacy, Fit Checker Advanced by GC (Figure 9).

• Occlusion is evaluated and modified if necessary. Material used: Accufilm 2 (Parkell) or Madame Butterfly (Almore).

• Patient is dismissed after thorough informed consent including denture expectations and necessary hygiene (Figure 10).

FIGURE 5

Stabilized occlusion rim— impression of final cast

made in resin-based occlusion rim (bite block).

FIGURE 6

Notched occlusion rim with Blu-Mousse by Parkell interocclusal record fitting into notches on wax recording

vertical dimension of occlusion

FIGURE 7

Trial denture ready for try-in and critique by dentist, assistant, and patient

FIGURE 9

Fit Checker Advanced by GC showing too much contact on left

side of post dam

FIGURE 8

Assistant made paste applied to inside of denture showing pressure spot

FIGURE 4

Border molded light viscosity wash impression

made over initial heavy body impression.

FIGURE 3

Border molded polyether Permadyne by 3M (heavy body) or VPS Aquasil Ultra by Dentsply Sirona (heavy body)

with adhesive placed on tray. Pressure spots are relieved.

• There is considerable interest in the digital denture concept by many labs and some dentists.

• Numerous companies have been working to provide the production of digital dentures, including 3Shape, AvaDent, Dentsply Sirona, Ivoclar Vivadent, and others. Digitizing the laboratory steps saves significant laboratory time, but making final impression analog denture is a clinical challenge explained in Clinical Tips on following page.

• Clinicians Report Foundation staff and clinicians have studied and tested some of the digital denture brands currently available on the market in comparison to conventional techniques including AvaDent (see Clinicians Report July 2012).

• In CR comparisons, it is clear that the digital denture concept can work well. However, one of the limitations is: the steps in denture fabrication are somewhat different from the conventional denture technique, and a learning curve is necessary for competency.

• A manual impression is necessary when making digital dentures, because the flexibility and movement of all of the gingival tissues does not allow for direct scanning of these tissues. It is evident when visiting dental laboratories that the making of complete denture impressions by dentists needs significant improvement. Many dentists have difficulty making an adequate complete denture impression, and as a result, the digital denture technique is often compromised.

Digital Dentures

FIGURE 10

Pleased patient at completion of denture procedure

Old Dentures

New Dentures

3Clinicians Report January 2019

Complete Dentures can be Easier to Make and More Successful (Continued from page 2)

Summary of Survey Results (n=961)• Average patient satisfaction with mandibular complete dentures:

– 0.6% High – 7.8% High to moderate – 32.3% Moderate – 43.9% Moderate to low – 15.4% Low• Average patient satisfaction with maxillary complete dentures:

– 13.2% High – 63.9% High to moderate – 21.2% Moderate – 1.7% Moderate to low – 0.0% Low• Average patient satisfaction with implant-supported complete dentures:

– 49.4% High – 46.0% High to moderate – 4.2% Moderate – 0.1% Moderate to low – 0.2% Low• Denture Making Techniques:

– Custom tray used: 54% – Impression material used: 55% VPS, 24%, alginate, 20% polyether– Bite block type used: 14% wax only, 77% resin base with wax on it, 10% resin

base and wax occlusion rim stabilized with VPS or polyether impression of final cast in occlusion rim.

– Gothic arch tracing used: 6%– Method of fabricating denture base: 34% conventional pressure pack,

21% injection molding, remainder of respondents unsure of method type. CR Note: See “Denture Base: What is Best?” below for more on this topic.

CR Observations:• Patient satisfaction with complete dentures was reported as

expected—maxillary: high to moderate; mandibular: moderate to low; and implant supported: moderate to high. This information should be discussed with patient when providing informed consent.

• There is no question that use of implants for support and retention of complete dentures provides a major improvement in patient satisfaction.

• The only significant negative factor when using implants is the significantly higher cost of implant supported and retained dentures.

Clinical Tips• Teach dental staff how to make adequate border molded alginate impressions.• Use custom trays or refine stock trays by trimming them or modifying them with additions.• Use elastomer impressions of the final cast to produce stabilized bite blocks.• Send complete information to your lab about smile line, midline, or any peculiar patient characteristics.• Do not let the lab technician polish your carefully border molded muco buccal fold. This simple tip can increase retention significantly.• Carefully adjust occlusion, pressure spots, and post-dam at seating.• Encourage complete denture patients who are still dissatisfied with their dentures to have implants placed.• Watch the continuing development of digital dentures, but FIRST upgrade your impression technique for success of both conventional and

digital dentures.

Denture Base: What is Best?• The two most common fabrication methods are: 1) Injection Molding, and 2) Pressure Pack (compression). Pressure pack is considered

the “conventional” method, yet still used by many (see CR survey results above).• Injection molding has demonstrated much better dimensional accuracy than pressure pack.1,2

This is due to continuous material injection to the mold during polymerization which helps compensate for material shrinkage, resulting in more precise adaptation to the eventual cast with minimal change in vertical dimension. Associated benefits include:

– Less chairside adjustments required– Less overall work time– Improved fit, comfort, and functionality for patient

• SR Ivocap by Ivoclar Vivadent has been well proven as a reliable injection molding system for denture base fabrication. Newer systems have not yet paralleled its excellence. In addition to complete dentures, it can also be used for: partial dentures, bases and relines, orthodontic appliances, and bite guard splints. To find a local dental technician skilled with the SR Ivocap System, please visit: www.ivoclarvivadent.us/company/rep-finder.Method Injection Molding Pressure Pack (compression)Representative product(CR Buying Guide December 2018) SR Ivocap (Ivoclar Vivadent) Lucitone 199 (Dentsply Sirona)*

Shrinkage (by volume) Excellent (2.2%)1 Fair (7.6%)1

Flexural Strength (mean) Excellent (98 MPa)3 Excellent–Good (91 MPa)3

* Also available with injection molding system (Success Injection System by Dentsply Sirona); similar material propertiesSources:

(1) Robison, R.A., Schwarting, R.H., Ellison, N., Schaalje, G.B. Measuring the fidelity and stability of denture resin injection systems. J. Dent. Mat. Vol 28, Sup 1, p. e34-e35. 2012.

(2) Gharechahi, J., Asadzadeh, N., Shahabian, F., Gharachahi, M. Dimensional Changes of Acrylic Resin Denture Bases: Conventional Versus Injection-Molding Technique. Journal of Dentistry, Tehran University. Vol. 11, No. 4., July 2014.

(3) Shibat Al Hamd YA, Dhuru VB. Physical and mechanical properties of pressure-molded and injection-molded denture base acrylics in different conditions. Saudi J Oral Sci 2014;1:65-70.

Products evaluated by CR Foundation® (CR®) and reported in the Gordon J. Christensen Clinicians Report® have been selected on the basis of merit from hundreds of products under evaluation. CR® conducts research at three levels: 1) multiple-user field evaluations, 2) controlled long-term clinical research, and 3) basic science laboratory research. Over 400 clinical field evaluators are located throughout the world and 40 full-time employees work at the institute. A product must meet at least one of the following standards to be reported in this publication: 1) innovative and new on the market, 2) less expensive, but meets the use standards, 3) unrecognized, valuable classic, or 4) superior to others in its broad classification. Your results may differ from CR Evaluators or other researchers on any product because of differences in preferences, techniques, product batches, or environments. CR Foundation® is a tax-exempt, non-profit education and research organization which uses a unique volunteer structure to produce objective, factual data. All proceeds are used to support the work of CR Foundation®. ©2019 This report or portions thereof may not be duplicated without permission of CR Foundation®. Annual English language subscription: US$229 worldwide, plus GST Canada subscriptions. Single issue: $29 each. See www.CliniciansReport.org for additional subscription information.

What is CR?WHY CR?CR was founded in 1976 by clinicians who believed practitioners could confirm efficacy and clinical usefulness of new products and avoid both the experimentation on patients and failures in the closet. With this purpose in mind, CR was organized as a unique volunteer purposeof testing all types of dental products and disseminating results to colleagues throughout the world.

WHO FUNDS CR?Research funds come from subscriptions to the Gordon J. Christensen Clinicians Report®. Revenue from CR’s “Dentistry Update®” courses support payroll for non-clinical staff. All Clinical Evaluators volunteer their time and expertise. CR is a non-profit, educational research institute. It is not owned in whole or in part by any individual, family, or group of investors. This system, free of outside funding, was designed to keep CR’s research objective and candid.

HOW DOES CR FUNCTION?Each year, CR tests in excess of 750 different product brands, performing about 20,000 field evaluations. CR tests all types of dental products, including materials, devices, and equipment, plus techniques. Worldwide, products are purchased from distributors, secured from companies, and sent to CR by clinicians, inventors, and patients. There is no charge to companies for product evaluations. Testing combines the efforts of 450 clinicians in 19 countries who volunteer their time and expertise, and 40 on-site scientists, engineers, and support staff. Products are subjected to at least two levels of CR’s unique three-tiered evaluation process that consists of:

1. Clinical field trials where new products are incorporated into routine use in a variety of dental practices and compared by clinicians to products and methods they use routinely.

2. Controlled clinical tests where new products are used and compared under rigorously controlled conditions, and patients are paid for their time as study participants.

3. Laboratory tests where physical and chemical properties of new products are compared to standard products.

This team is testing resin curing lightsto determine

their ability to cure a variety of resin-based

composites.

Every month several new projects arecompleted.

THE PROBLEM WITH NEW DENTAL PRODUCTS.

New dental products have always presented a challenge to clinicians because, with little more than promotional information to guide them, they must judge between those that are new and better, and those that are just new. Because of the industry’s keen competition and rush to be first on the market, clinicians and their patients often become test data for new products.

Every clinician has, at one time or another, become a victim of this system. All own new products that did not meet expectations, but are stored in hope of some unknown future use, or thrown away at a considerable loss. To help clinicians make educated product purchases, CR tests new dental products and reports the results to the profession.

Clinical Success is the Final Test

Clinicians Report® a Publication of CR Foundation®3707 N Canyon Road, Building 7, Provo UT 84604

Phone: 801-226-2121 • Fax: 801-226-4726CR@CliniciansReport.org • www.CliniciansReport.org

CRA Foundation® changed its name to CR Foundation® in 2008.

4Clinicians Report January 2019

Complete Dentures can be Easier to Make and More Successful (Continued from page 3)

CR CONCLUSIONS: Making satisfactory complete dentures (non-implant supported/stabilized) requires meticulous planning, significant staff involvement, personal interaction with laboratory technicians, a significant amount of artistic ability on the part of the dentist and staff, and continued follow-up as bone- and soft-tissue changes occur. With increased staff involvement in the clinical steps, the complete denture procedure can be relatively simple, satisfying to patients, relatively inexpensive, and profitable for practices. Use of implants supporting either removable or fixed complete dentures improves patient satisfaction markedly but is much more expensive.