Quintessence International, 06/1999

Metal posts used to restore endodontically treated teeth may shine through all-ceramic crowns and thin gingival tissue. When nonprecious alloys are used, corrosion products may lead to discoloration. All-ceramic posts and cores can be used in combination with all-ceramic crowns to prevent these problems. All-ceramic posts and cores are highly biocompatible and will almost always increase the translucency of an all-ceramic restoration. The purpose of this article is to describe the fabrication of all-ceramic posts and cores, using high-toughness ceramic materials such as alumina or zirconia ceramics, through 4 different techniques: the slip-casting technique; the copy-milling technique; the 2-piece technique, which involves a prefabricated zirconia ceramic post and a copy-milled alumina or zirconia ceramic core; and the heat-press technique, which involves a prefabricated zirconia ceramic post and a heat-pressed glass-ceramic core. Indications, contraindications, advantages, and disadvantages of the different techniques are compared.

Objective: The purpose of this study was to ascertain the ease of interpretation and usefulness of different modes of presenting quantitative tooth wear data to clinicians. Method and Materials: A questionnaire that sought to ascertain both the ease of interpretation and usefulness of different modes of presentation for monitoring tooth wear was distributed to 67 clinicians. These modes (contour maps, surface topography and difference plots, and color-coded surface difference plots) were a product of ongoing development that used a mathematic algorithm to detect and quantify wear of teeth with time. A follow-up questionnaire, based on a fusion of the desirable features of surface topography and color-coded surface difference plots, was distributed to 40 of the original respondents to ascertain any improvement in clarity. Results: In all respects, contour maps were rated significantly more difficult to interpret and less useful than the other techniques evaluated. No significant difference was detected between the other modalities. The follow-up questionnaire demonstrated a significantly enhanced utility of the revised plot in informing the clinician as to the worn sites and quantity of wear. Conclusion: The combined mode of presentation seems an excellent way of presenting wear results to clinicians for clinical application.

Dr Marshall Webb (1844-1883), author, lecturer, debater, clinician, inventor, and dentist extraordinaire, was a decade ahead of others in putting forth a concept of 'extension for prevention.' One hundred twenty years ago, he was one of the best known, most advanced, and highly regarded dentists in the world. His pioneering work in cariology, preventive dentistry, ethics, and prevention of recurrent decay raised the standards of what we call operative or conservative dentistry, but he is almost unknown now. However, his concept of conservative tooth preparation could be applied today.

Objective: A general dental practice study investigated the use of a resin-modified glass ionomer material as a transitional restoration and as a core buildup material. The study also assessed a resin-modified glass-ionomer luting system. Method and materials: Fifty-one badly broken-down vital permanent molar teeth in 44 patients were restored. No dentin pins were placed; however, preexisting pins were retained in 7 teeth. Following baseline and 3-month assessments, complete veneer gold crowns were placed on the selected teeth. The preparations involved ferruling in sound tooth tissue. The completed crowns were reviewed 3 and 12 months after placement. Modified US Public Health Service criteria were used for assessment throughout. Clinical assessment was complemented by examination of photographic records and replicas obtained from silicone impressions. Results: All 51 transitional restorations were found to be clinically satisfactory at the 3-month review. Nineteen (37%) transitional restorations had limited defects that were eliminated in crown preparation. Of the 51 permanent crowns, 46 (90%) were reviewed at 3 months and 44 (86%) at 1 year. All the crowns reviewed at 3 and 12 months were clinically satisfactory. The luting system investigated showed favorable handling characteristics and excellent short-term performance. Conclusion: The materials investigated are, over a period of at least 12 months, effective in the restoration of broken-down molar teeth destined to be crowned. With the use of these materials and ferruling, the use of dentin pins may be unnecessary in selected cases.

Objective: The purpose of this investigation was to evaluate the influence of finishing and polishing procedures on the decision to replace existing amalgam restorations. Method and materials: Twenty Class I and Class II amalgam restorations, free from obvious defects, were selected in 6 patients. The restorations were photographed before and after being submitted to a standard finishing and polishing procedure. In the first phase, the preoperative slides were examined by 27 clinicians and senior dental students, who were instructed to inspect each restoration and answer a questionnaire indicating if and why the restoration needed to be replaced. Two weeks later, the postoperative slides were presented to the same examiners, who were asked to answer the same questionnaire as before. Results: At the first phase, there were 236 decisions (44%) to replace existing amalgam restorations. Following the finishing and polishing procedures, 114 decisions (21%) were made to replace existing amalgam restorations. This difference was statistically significant. Secondary caries was the most common reason for replacement. Conclusion: The finishing and polishing procedure reversed the decision to replace old amalgam restorations.

Problems encountered in placement of posterior resin composite restorations have limited their clinical application. This article identifies and solves 4 of the frequently encountered problems: establishment of tight and anatomically correct contacts, refinement of occlusion, postoperative sensitivity, and time required for the procedure. A posterior resin composite is placed using a self-etching primer. A novel matrix, flowable composite, and bite-formed occlusion facilitate the clinical procedure.

Apert syndrome is a rare congenital anomaly characterized by acrocephaly, syndactyly, and abnormalities of other organs. It has characteristic features in the orofacial region, affecting the eyes, palate, middle third of face, and uvula. In this case report, the features of Apert syndrome, particularly in relation to the orofacial region, are discussed.

Objective: The purpose of this study was to evaluate the effectiveness of various surface treatments for resin-modified glass-ionomer restorative materials by determining dye uptake spectrophotometrically. Method and materials: Two hundred twenty-four specimens, 4.1 mm in diameter and 2.0 mm thick, were made of 3 materials: Vitremer, Fuji II LC, and Photac-Fil Aplicap. Specimens were divided into 15 groups. The positive and negative control specimens remained unprotected, while the experimental specimens were protected with Heliobond light-activated bonding resin, Colorama nail varnish, or surface coatings indicated by the manufacturers of the glass-ionomer materials: Finishing Gloss for Vitremer, Fuji Varnish for Fuji II LC, and Ketac Glaze for Photac-Fil. The disks were immersed in 0.05% methylene blue for 24 hours except for the negative control group, which was immersed in deionized water. After 24 hours, the disks were removed, washed, and individually placed in 1 mL of 65% nitric acid for 24 hours. The solutions were centrifuged and the spectrophotometric absorbance was determined at 606 nm. The dye uptake was expressed in micrograms of dye per milliliter, and the results were analyzed with the Kruskal-Wallis test. Results: There were no differences in dye uptake among the 3 resin-modified glass-ionomer restorative materials; however, all of them required surface protection. Conclusion: The best surface protection for the 3 evaluated materials was obtained with Heliobond light-activated bonding resin.