Quintessence International, 08/2001

Objective: Dentin-bonded crowns are a comparatively recent addition to the dentist's armamentarium. Although 1-year data cannot predict the long-term performance of restorations, it may be useful for new treatment modalities, given that it will describe early, catastrophic failures. In this study, the 1-year performance of 109 dentin-bonded crowns was assessed. Method and materials: The crowns were placed in two locations (Glasgow, Scotland, and Belfast, Northern Ireland) for 27 patients. The principal reasons for crown placement were tooth substance loss, esthetic reasons, and tooth fracture. Minimal preparations were used. Ninety-eight crowns were available for review at 1 year. Results: Ninety crowns were found to be intact, six had a crack visible on transillumination and two had fractured. No crowns had debonded. No secondary caries was noted. No unsatisfactory scores were recorded for marginal adaptation, adjacent gingival health, or color match. Conclusion: The dentin-bonded crowns placed during this study provided good overall performance at 1 year.

Objective: Single-crown preparations at a dental teaching hospital were compared with guidelines advocated in the dental literature. Method and materials: Sixty-three single complete gold crown and 151 single ceramometal crown preparations were evaluated. Impression silhouettes were measured for occlusal and axial wall tooth reductions, shoulder widths, internal shoulder angles, and axial wall convergence angles. Marginal designs, the presence of retention grooves and undercuts, and the types of cores present were also recorded. Results: Cuspal reduction was generally inadequate for the ceramometal crowns, and central fossa reduction was insufficient for both complete gold crowns and ceramometal crowns. The facial shoulder widths were also generally underprepared for the ceramometal crowns. Axial wall convergence angles for both complete gold crowns and ceramometal crowns were generally much greater than recommended. Large faciolingual convergence angles for anterior ceramometal crowns were associated with the absence of cingulum walls. Few preparations had retention grooves or undercut areas. Conclusion: Although strict guidelines for tooth preparations for complete crowns are available and well known to dentists, the preparations in this study did not always conform to these recommendations.

Physiologic and histopathologic experimental studies over the last 30 to 40 years have demonstrated that the healing of the dental pulp is comparable to that of connective tissue elsewhere, despite its location in the low-compliance pulp chamber. The greatest difficulty from a clinical point of view is to assess cellular changes and vitality of the pulp. If it is vital, the potential for repair is present, especially in young individuals.

This case report presents the relatively uncommon occurrence of a maxillary second premolar with 3 root canals. The possibility of additional root canals should be considered even in teeth with a low frequency of abnormal root canal anatomy. Sound knowledge of root canal anatomy, critical interpretation of radiographs, and high-magnification examination are essential elements of success in complicated root canal therapy.

Examination of the early literature of dental radiology reveals that dental scientists of the time were eager to experiment with the new technology but were unaware of the dangers associated with radiation.

Objective: The purpose of this study was to determine whether the incidence of pathologic conditions affecting the pericoronal tissue of unerupted third molars justifies their routine removal. Method and materials: The pericoronal tissue associated with completely unerupted third molars was submitted for histologic examination after surgical tooth removal was performed in 37 males and 55 females, aged 13 to 63 years. The 104 unerupted third molars comprised 68 mandibular third molars (65.38%) and 36 maxillary third molars (34.62%). Results: The incidence of normal tissue of a dental follicle was 41.35%, and the incidence of pathologic tissue was 58.65% (dentigerous cyst, 50.96%; chronic nonspecific inflammatory tissue, 4.81%; odontogenic keratocyst, 1.92%; ameloblastoma, 0.96%). The incidence of pathologic conditions was higher than that of normal conditions in all third molar positions. In younger patients, normal tissue was more commonly found, but in patients older than 20 years, the incidence of pathologic tissue was higher than the incidence of normal tissue. Conclusion: Unerupted third molars should be removed before pathologic changes can occur in their pericoronal tissues. This justifies routine removal of unerupted third molars from patients older than 20 years.

Objective: The purpose of this investigation was to study the development of the premolars in a sample of Greek children with cleft lip and palate. Method and materials: The study material consisted of panoramic radiographs of 34 individuals (22 boys and 12 girls) with cleft lip with or without cleft palate. The boys ranged from 9.0 to 14.0 years of age and the girls ranged from 8.0 to 14.5 years of age. The mean age was 11.3 years. Each panoramic radiograph was matched with a corresponding one of an unaffected individual of the same sex and chronologic age (± 3 months). The panoramic radiographs were used to categorize the stages of tooth development according to the 10 stages of mineralization described by Nolla. The assessment was repeated by a second observer. Results: Individuals with clefts exhibited a statistically significant delay of formation and mineralization of the maxillary right and left second premolars and the mandibular right second premolar in comparison to individuals without clefts. In the cleft group, there was no statistically significant difference between boys and girls in premolar development. No asymmetric development of contralateral premolar teeth was observed in individuals with cleft lip and palate. Conclusion: Although the exact biologic explanation remains to be found, the formation of premolars is delayed in children with cleft lip and palate.

Objective: Black tea (Camellia sinensis) may have anticariogenic properties. The present study was designed to determine whether consumption of black tea influences cariogenesis in young, caries-prone rats. Method and materials: Eighteen-day-old Sprague-Dawley rats (n = 24; eight per group) fed a cariogenic diet (MIT 200) were randomly assigned to three groups to receive deionized, distilled fluoride-free water, tea, or fluoridated water (25 ppm), ad libitum, for 14 days. In addition, an initial control group of rats was studied at 20 days of age. Teeth were stained with silver nitrate to detect caries and cut mesiodistally. First and second molars were assessed for caries. Results: The initial control group had negligible caries. Caries-prone rats consuming fluoride-free water had significantly more caries lesions (6.75) than did the tea (3.12) and the fluoridated water (0.85) groups. Conclusion: Consumption of black tea for 2 weeks attenuated development and progression of caries in caries-prone young rats.

Dr Camille B. Capdeboscq taught operative dentistry at Louisiana State University School of Dentistry from 1972 until his retirement in 1996. Before that, he had practiced for 9 years, partly in Louisiana's bayou country. With a reputation for clinical excellence, he became a legendary figure at LSU for his humility, his generosity of spirit, and his humanitarian dedication to students. Despite his demand for the highest of standards, and his toughness in grading, his students nonetheless loved and revered him for his ability to inspire confidence, stimulate learning, and instill a sense of dignity at each encounter. Dr Capdeboscq also inspired his colleagues to look at their own character and values.