Patrick M. Lloyd

The philosophies of dowel diameter preparation: a literature review.

This article reviewed the literature regarding the diameter of dowels and identified three distinct philosophies of dowel space preparation. One group advocated the narrowest diameter for fabrication of a dowel to a desired length. Another recommended a dowel space with an apical diameter equal to one third of the narrowest dimension of the root at the terminus of the dowel. A third group advised that at least 1 mm of sound dentin should surround the entire surface of the dowel. A combination of the one third and 1 mm minimal philosophies yielded a practical guideline for dowel space preparation, particularly in aged teeth. Requiring a definite amount of tooth structure surrounding the dowel, while adhering to the one third proportion, indicated upper limits on both the diameter and length of the dowel. These calculated limits served as convenient starting points in selecting a specific style of dowel and assisted in determining whether additional measures are warranted to enhance dowel retention.

A comparison of the effects of two burs on endodontic access in all-ceramic high lucite crowns.

OBJECTIVE The purpose of this study was to examine and compare the effects of diamond and tungsten carbide burs with respect to the preparation of access through all-ceramic crowns. STUDY DESIGN Thirty extracted maxillary premolars were restored with all-ceramic crowns. Each specimen was assigned to one of two groups: (1) access opening prepared with a round diamond bur; (2) access opening prepared with a carbide fissure bur. Access preparations were scanned by means of scanning electron microscopy; observed were defects categorized as edge chipping, microcracks, and fractures. RESULTS Edge chipping around the access was universal. Significant chipping (x > or = 0.1 m) was seen in 43% of access peripheries. Eleven percent of the crowns fractured. chi(2) analysis (P <.05) demonstrated no statistical difference between the bur groups. Results of a t test revealed no statistical difference in edge chipping between the two bur types. CONCLUSIONS All-ceramic crowns bonded to extracted maxillary premolars may experience edge chipping, microcracks, and fractures at equal rates whether access is prepared with a round medium coarse diamond bur or a tungsten carbide fissure bur.

Fixed prosthodontics and esthetic considerations for the older adult.

A new generation of older adults, who are more educated, health-conscious, and economically independent than their predecessors is bringing a fresh perspective and poses unique opportunities and challenges to fixed prosthodontics. Subtle differences in technique, attention to detail, and innovative application of materials and procedures are the main ingredients of successful fixed prosthodontic care for seniors. The goals of fixed prosthodontics for the older adult are fundamentally different from those for a younger population. A practice that enhances the integrity of residual tooth structure while simultaneously creating an environment less prone to dental disease and disability should be emphasized.

Users' guide to the dental literature: How to use an article about prognosis

With the growing need for documented efficacy of treatment and efficiency of rendering care, prosthodontists will serve their patients best when they fully understand the intricacies of clinical research and the results reported. This article proposes a structure for evaluating the literature that pertains to prognosis--the prediction of outcomes and frequency of such occurrences.