Statement of problem Computer-aided technology is an emerging method for fabricating complete dentures. Consolidated information about historical background, current status, and scope for the future is lacking. Purpose The purpose of this systematic review was to analyze the existing literature on computer-aided technology for fabricating complete dentures and provide the reader with a historical background, current status, and future perspectives on this emerging technology. Material and methods An electronic search of the English language literature between the periods of January 1957 and June 2012 was performed by using PubMed/MEDLINE with the following specific search terms: CAD-CAM complete dentures, digital complete dentures, computer dentures, designed dentures, machined dentures, manufactured dentures, milled dentures, and rapid prototyping dentures. Additionally, the search terms were used on the Google search engine to identify current commercial manufacturers and their protocols. Results A total of 1584 English language titles were obtained from the electronic database, and the systematic application of exclusion criteria resulted in the identification of 8 articles pertaining to computer-aided technology for complete dentures. Since the first published report in 1994, multiple authors have described different theoretical models and protocols for fabricating complete dentures with computer-aided technology. Although no clinical trials or clinical reports were identified in the scientific literature, the Google search engine identified 2 commercial manufacturers in the United States currently fabricating complete dentures with computer-aided design and computer-aided manufacturing (CAD/CAM) technology for clinicians world-wide. These manufacturers have definitive protocols in place and offer exclusive dental materials, techniques, and laboratory support. Their protocols contrast with conventional paradigms for fabricating complete dentures and allow the fabrication of complete dentures in 2 clinical appointments. Conclusions A body of scientific literature related to computer-aided technology for complete dentures is emerging. Significant advancements in this technology have now resulted in their commercial availability with shorter clinical protocols. However, prospective clinical trials with true clinical endpoints are necessary to validate this technology. This could affect dental education, patient care, research, and public health worldwide.

Computer-aided technology for fabricating complete dentures: systematic review of historical background, current status, and future perspectives.

A luting agent’s primary function is to fill the minute void between an indirect restoration (definitive or provisional) and tooth (or implant abutment) and mechanically lock the restoration in place to prevent dislodgement during function. The purpose of this paper is to provide a clinically focused discussion on the broad spectrum of luting materials currently available to help the general practitioner make appropriate choices. Resins are typically formulated for a specific function or restoration and offer strength, aesthetics, flexible working times, and very low solubility yet are technique sensitive, expensive and often hard to clean-up. Glass-ionomers offer good strength and optical properties plus the potential for fluoride release/recharge but may have short working times, are sensitive to moisture or dehydration early on, and take time to fully set. Resin-modified glass-ionomers are hybrid, dual-phase materials which are manipulated like glass-ionomer but set quicker and are stronger. Zinc phosphate cement, used successfully for over a century to lute well-fitting metal and metal-ceramic definitive restorations, is a very inexpensive, rigid material which displays very high early compressive strength yet acidity and solubility can be problems. Polycarboxylate cement (a hybrid of zinc phosphate) has lower compressive strength but high tensile strength and may be less injurious to the pulp. Zinc oxide eugenol and zinc oxide non-eugenol cements typically have good sealing abilities but their relatively low compressive and tensile strengths, inherent brittleness, and high solubility limit usage to provisional restorations or implant supported crowns. Claims for multi-purpose or universal use by manufacturers can be somewhat confusing and overwhelming. Even so, the busy general practitioner must have sufficient knowledge to help choose an appropriate luting agent for each unique clinical situation.

https://www.onlinelibrary.wiley.com/doi/pdf/10.1111/j.1834-7819.2010.01297.x

A clinically focused discussion of luting materials

This study compared shear bond strengths of six self-adhesive resin cements to zirconium oxide ceramic with and without air-particle abrasion. One hundred twenty zirconia samples were air-abraded (group SB; n = 60) or left untreated (group NO). Composite cylinders were bonded to the zirconia samples with either BisCem (BC), Maxcem (MC), G-Cem (GC), RelyX Unicem Clicker (RUC), RelyX Unicem Applicator (RUA), or Clearfil SA Cement (CSA). Shear bond strength was tested after thermocycling, and data were analyzed with analysis of variance and Holm–Sidak pairwise comparisons. Without abrasion, RUA (8.0 MPa), GC (7.9 MPa), and CSA (7.6 MPa) revealed significantly higher bond strengths than the other cements. Air-particle abrasion increased bond strengths for all test cements (p < 0.001). GC (22.4 MPa) and CSA (18.4 MPa) revealed the highest bond strengths in group SB. Bond strengths of self-adhesive resin cements to zirconia were increased by air-particle abrasion. Cements containing adhesive monomers (MDP/4-META) were superior to other compositions.

In vitro comparative bond strength of contemporary self-adhesive resin cements to zirconium oxide ceramic with and without air-particle abrasion

Rubber dam has been available to the dental profession for over 140 years. During this time, the use of rubber dam has been perfected, universally taught and recommended by professional organizations. Unfortunately, its consistent use has been rejected by many in the profession. The literature suggests that rubber dam is not used routinely by dental practitioners for root canal treatment. Many unfounded reasons have been cited for its lack of use, including concerns over patient acceptance, time required for application, cost of equipment and materials, insufficient training, difficulty in use and low treatment fees. Failure to use rubber dam has been shown to influence the choice of root canal irrigant, has a negative impact on treatment outcome and places the patient at risk of swallowing or aspirating materials and instruments. Methods to popularize rubber dam amongst general practitioners are discussed.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-2591.2009.01623.x

Rubber dam usage for endodontic treatment: a review.

Shear bond strengths of various luting cements to zirconia ceramic: surface chemical aspects.

https://www.dental.theclinics.com/article/S0011-8532(07)00017-1/pdf

Dental Cements for Definitive Luting: A Review and Practical Clinical Considerations

Most dentists are educated in rubber dam use in dental school, but there is often disparity between what is taught for various restorative procedures and what is practiced in the private sector. It is a common, although undocumented, belief that few practicing dentists routinely use rubber dam isolation. This study repeated a survey conducted in 1985 evaluating U.S. general dentists' attitudes toward rubber dam usage to see if improvement is needed in current dental educators' approach to this topic. Four hundred dentists were selected randomly from ten major geographically diverse cities using the website YellowPages.com. Each was mailed a letter requesting survey participation, which included a pre-stamped, pre-addressed postcard with the survey printed on the back. The target population, general dentists, returned 164 surveys (41 percent). Their responses can be summarized as follows: 71 percent do amalgams-of those, 53 percent never use a rubber dam whereas 12 percent always use a rubber dam; 100 percent do anterior direct resin composites-of those, 45 percent never use a rubber dam whereas 17 percent always use a rubber dam; 98 percent do posterior direct resin composites-of those, 39 percent never use a rubber dam and 18 percent always use a rubber dam; and 78 percent do endodontic procedures-of those, 11 percent never use a rubber dam whereas 58 percent always use a rubber dam. Most (74 percent) felt that their dental school rubber dam training was adequate; 42 percent felt that its use has an effect on the quality of restorative dentistry. Their most common reasons for not using a dam were the following: inconvenience (40 percent); unnecessary (28 percent); other (12 percent); patient refusal (11 percent); and time (9 percent). No respondent indicated that "cost" was a reason for not using rubber dams. This study indicates that many general dentists in this country continue to ignore the rubber dam for many restorative and some endodontic procedures. It indicates that predoctoral dental educators need to look for opportunities for improvement to reduce the discrepancy between what is taught and the general practice of dentistry.

Do Dental Educators Need to Improve Their Approach to Teaching Rubber Dam Use

Most dental procedures are accomplished while the patient is partially or totally supine; as a result, all restorative patients have the potential to ingest or aspirate a dental item. The principle of nonmaleficence dictates the use of preventive practices (rubber dam, ligatures, throat pack) when possible; even so, accidents happen and one has to assume the worst when a dental item disappears. Knowing what to do can be extremely important, both medically and legally. The first order of business is ensuring that the airway is not compromised and advising the patient of the problem. Immediate referral (with escort) to a medical facility for appropriate radiographs and determination of required medical action is mandatory, regardless of how well the patient looks. According to the literature, all aspirated foreign objects and approximately one-third of ingested items require the patient to be hospitalized. Proper documentation also is important to reduce liability in the event of litigation.

A practical review of prevention and management of ingested/aspirated dental items.

For various reasons, dentists may be tempted to definitively tighten implant abutment screws using only handheld screwdrivers. The purpose of this study was to test the ability of general ...

Implant abutment screw torque generated by general dentists using a hand driver in a limited access space simulating the mouth

In order to create optimum esthetics, function and phonetics in complete denture fabrication, it is necessary to record accurate maxillo-mandibular determinants of occlusion. This requires clinical skill to establish an accurate, verifiable and reproducible vertical dimension of occlusion (VDO) and centric relation (CR). Correct vertical relation depends upon a consideration of several factors, including muscle tone, inter-dental arch space and parallelism of the ridges. Any errors made while taking maxillo-mandibular jaw relation records will result in dentures that are uncomfortable and, possibly, unwearable. The application of a tracing mechanism such as the Gothic arch tracer (a central bearing device) is a demonstrable method of determining centric relation. Intraoral Gothic arch tracers provide the advantage of capturing VDO and CR in an easy-to-use technique for practitioners. Intraoral tracing (Gothic arch tracing) is a preferred method of obtaining consistent positions of the mandible in motion (retrusive, protrusive and lateral) at a comfortable VDO.

Edward E Hill

Papers

Dental Cements for Definitive Luting: A Review and Practical Clinical Considerations

Do Dental Educators Need to Improve Their Approach to Teaching Rubber Dam Use

A practical review of prevention and management of ingested/aspirated dental items.

Implant abutment screw torque generated by general dentists using a hand driver in a limited access space simulating the mouth

Intraoral gothic arch tracing.