Robert J. Cronin

Annual review of selected dental literature: Report of the Committee on Scientific Investigation of the American Academy of Restorative Dentistry

This review was conducted to assist the busy dentist in keeping abreast of the latest scientific information regarding the clinical practice of dentistry. Each of the authors, who are considered experts in their disciplines, was asked to peruse the scientific literature in their discipline published in 2016 and review the articles for important information that may affect treatment decisions. Comments on experimental methodology, statistical evaluation, and the overall validity of conclusions are included with many of the reviews. The reviews are not meant to stand alone but are intended to inform the interested reader about what has been discovered in the past year. The readers are then invited to go to the source, if they want more detail.

Prosthodontic management of ectodermal dysplasia: a review of the literature.

Ectodermal dysplasia is commonly a difficult condition to manage with prosthodontics because of the typical oral deficiencies and because the afflicted individuals are quite young when they are evaluated for treatment. It is important that these individuals receive dental treatment at an early age for physiologic and psychosocial reasons. This article reviews the literature that pertains to the prosthodontic treatment of the disorder and the review includes considerations in behavior management and timing of treatment.

Consensus conference panel report: crown-height space guidelines for implant dentistry-part 1.

The International Congress of Oral Implantologists sponsored a consensus conference on the topic of Crown Height Space on June 26–27, 2004 in Las Vegas, Nevada. The panel communicated on several occasions before, during, and after the meeting, both as a group and among individuals. A consensus of one opinion was not developed for most issues. However, general guidelines emerged related to the topic. The following article is Part 2 of a summary of several of the guidelines that should be of benefit to the profession at large. (Part 1 appeared in Implant Dentistry 2005;14:312–321.)

Prevalence and association of headaches, temporomandibular joint disorders, and occlusal interferences

STATEMENT OF PROBLEM Although an interaction of malocclusion, parafunction, and temporomandibular joint disorders (TMD) can be inferred from the experience of daily practice, scientific evidence to corroborate this hypothesis does not exist. However, there are indications that TMD and headaches may be intertwined. PURPOSE The purpose of this study was to identify the presence or absence of an association of occlusal interferences, parafunction, TMD, or physiologic, muscular, or prosthodontic factors with the occurrence of headache. MATERIAL AND METHODS In a private practice population of 1031 subjects (436 men and 595 women, mean age 49.6 years) the demographic parameters, headache and general pain history, habits and general personal information were recorded. Clinical examination for dental, muscular, and temporomandibular joint pathology was accomplished. Data were statistically analyzed using the Mann-Whitney U, Kruskal-Wallis, and Chi-Square tests (α = .05). A multinomial logistic regression analysis was performed with respect to confounding variables. RESULTS Headache affliction was found to affect women more frequently than men (1.7:1). Students and non academics were more prone to suffer from headache. Parafunction (P=.001), TMD (P=.001) and gross differences between centric occlusion and maximum intercuspation of more than a 3 mm visible track marked with 8 μm articulation foil (P=.001) significantly influenced the presence of headache. Headache intensity and frequency decreased with age. While tension-type headache was most frequently diagnosed, the parameters studied were not significantly associated with one certain headache diagnosis more frequently than others. CONCLUSIONS Stomatognathic factors of TMD, parafunction, and gross differences between centric occlusion and maximum intercuspation of more than 3 mm are associated with headache. These findings should be interpreted with caution due to the cross-sectional nature of this study.

Effect of metal design and technique on the marginal characteristics of the collarless metal ceramic restoration

This investigation examined the marginal characteristics of the collarless metal ceramic restoration made with two commonly used direct-lift techniques: (1) a porcelain/wax paste and (2) a porcelain/liquid slurry. The metal copings touched the shoulder in half of the groups and were left 0.5 mm short in the other half to comprise the four experimental groups. Marginal seal was evaluated at facial and lingual surfaces on embedded and sectioned specimens for each group. Photo negatives were made of each specimen and projected at a constant magnification so that tracings could be made of the space between the die shoulder and corresponding porcelain. Composite surface measurements were made for each sample with a Zeiss Interactive Digital Analysis System instrument to evaluate porcelain adaptation to the shoulder. The porcelain/liquid groups demonstrated significantly smaller (p less than or equal to 0.05) facial marginal openings than the porcelain/wax groups. The group made with the porcelain/liquid technique with the metal on the die shoulder produced the most consistent overall results. The porcelain/liquid group with the metal off the shoulder had a statistically larger (p less than or equal to 0.05) mean marginal opening from the external margin to a point 0.75 mm to the interior than both techniques with the metal on the shoulder. Lingual marginal adaptation did not vary with each of the four experimental groups.

Refining cast implant-retained restorations by electrical discharge machining.

The UCLA abutment was developed to create implant-retained restorations with ideal contours, excellent esthetics, and minimal vertical space requirements for restorative materials. A major drawback of this abutment is that casting inaccuracies in the lost-wax process are difficult to control. This article describes a method of refining cast implant-retained restorations by use of electrical discharge machining.

Restorative considerations for a fixed implant prosthesis using different root form implant systems

A precise fit at the prosthesis attachment interface is necessary to assure atraumatic loading of the implant fixture. The required high degree of frame accuracy can be more difficult to achieve when a single fixed prosthesis uses different root form implant systems for support. Two clinical protocols are described for these fixed implant prostheses. The first protocol uses a semiprecision attachment for the restorations. The second protocol uses a modified abutment system and a one-piece frame design.