Longitudinal study of bone density and periodontal disease in men

Bone loss is a feature of both periodontitis and osteoporosis, and periodontal destruction may be influenced by systemic bone loss. This study evaluated the association between periodontal disease and bone mineral density (BMD) in a cohort of 1347 (137 edentulous) older men followed for an average of 2.7 years. Participants were recruited from the Osteoporotic Fractures in Men Study. Random half-mouth dental measures included clinical attachment loss (CAL), pocket depth (PD), calculus, plaque, and bleeding. BMD was measured at the hip, spine, and whole-body, by dual-energy x-ray absorptiometry, and at the heel by ultrasound. After adjustment for age, smoking, race, education, body mass index, and calculus, there was no association between number of teeth, periodontitis, periodontal disease progression, and either BMD or annualized rate of BMD change. We found little evidence of an association between periodontitis and skeletal BMD among older men.     

The position of the apical foramen of the permanent incisors

The position of the apical foramen in relation to the anatomical root apex is of considerable importance to the dentist, especially when the level of obturation of the root canal is determined through tooth length calculated radiologically. The main objective of this study was to determine in upper permanent incisor teeth, the position of foramen/foramina relative to the anatomical apex.
In 635 permanent upper incisors, the results of this study showed 54.3 per cent with the foramen coincident with the root apex, and 45.7 per cent where the root apex and the foramen were non-coincident. The average distance of the foramen from the root apex in the latter group was 0.35 mm and it ranged from 0.1 to 1.2 mm. The significance of these findings is discussed in relation to the apical termination of debridement and obturation of root canals.     

Effectiveness and dentin bond strengths of two materials for reinforcing thin-walled roots.

OBJECTIVES: To investigate the effectiveness of two restorative materials for reinforcing thin-walled roots and their microtensile bond strengths to root canal dentin. METHODS: Twenty-one decoronated maxillary central incisor roots were root filled and the canals enlarged to leave approximately 1.0 mm thick dentin walls. The roots were distributed randomly to three equal groups. Group 1 (control): a large tapered cast post-core was fabricated. Group 2 (BIS-CORE): a thick layer of dual-cured composite was placed in the post-hole before fabrication of a small-diameter tapered cast post-core. Group 3 (ChemFil Superior): a thick layer of glass-ionomer was placed, as before. Metal-ceramic crowns were fabricated for all teeth. Microtensile bond strength tests and optical and atomic force microscope observations were employed to examine adhesion between the two restorative materials and the root canal dentin. RESULTS: Mechanical loading (kN) demonstrated that composite 0.64 (S.D. 0.05), but not glass-ionomer 0.49 (0.05), significantly reinforced the fracture resistance of thin-walled roots, P<0.001. Microtensile bond strengths (MPa) were 21.7 (1.6) for composite and 12.9 (1.7) for glass-ionomer, P=002. SIGNIFICANCE: A thick intermediate layer of resin-bonded composite, sandwiched between the root dentin and a small-diameter cast Ni-Cr post or dowel, increased significantly the fracture resistance of the roots.     

Gingival recession: part 2. Surgical management using pedicle grafts

This paper is the second in a three part series looking at the aetiology and management of gingival recession. Part one discussed the aetiology and non-surgical management and this part aims to discuss the use of pedicle soft tissue grafts in the treatment of gingival recession. This article also considers the factors affecting the outcome of surgical procedures used to treat localised recession defects. The third paper in this series will consider the use of free soft tissue grafts and guided tissue regeneration.     

Dubowitz syndrome: report of a case with emphasis on the oral features

Dubowitz syndrome is a rare condition in which the affected individual presents with dysmorphic facial features and manifests growth retardation. Although the condition is well reported in the medical literature, the dental manifestations have not been discussed in great detail. Some of the dental features reported include macrodontia, hypodontia, delayed eruption, and midline diastema. The purpose of this case report was to describe a young Chinese patient with Dubowitz syndrome with specific oral features.     

Effect of finish line variants on marginal accuracy and fracture strength of ceramic optimized polymer/fiber-reinforced composite crowns

STATEMENT OF PROBLEM: Ceramic optimized polymer (Ceromer)/fiber-reinforced composite (FRC) crowns have been promoted as alternatives to conventional crowns. However, little is known regarding the ideal tooth preparation for this type of crown. PURPOSE: This in vitro study evaluated the marginal adaptation and fracture strength of ceromer/FRC crowns with respect to the various types of finish lines. MATERIAL AND METHODS: Four metal dies with different finish lines (0.9-mm chamfer, 1.2-mm chamfer, 1.2-mm rounded shoulder, and 1.2-mm shoulder) were prepared. Forty (10 for each finish line) Targis/Vectris crowns were fabricated on duplicated base metal alloy dies. The restorations were stereoscopically evaluated at 56 points along the entire circumferential margin for measuring the margin adaptation before and after cementation with a resin luting agent. The specimens were then compressively loaded to failure using a universal testing machine. The marginal adaptation (microm) was analyzed with the Kruskal-Wallis test and post-hoc Dunnett test (alpha=.05). The fracture load (N) was analyzed with a 1-way analysis of the variance and the Scheffe adjustment (alpha=.05). The fractured surfaces of the crowns were examined with a scanning electron microscope to determine the mode of fracture. RESULTS: The marginal adaptation of crowns with a shoulder finish line was significantly better than crowns with a chamfer finish line before and after cementation (P<.001). The increased marginal gap after cementation was the lowest in the 1.2-mm rounded shoulder group. The fracture strength of the crowns with the 0.9-mm chamfer and crowns with 1.2-mm chamfer was significantly greater than those of the crowns with the 1.2-mm shoulder or rounded shoulder (P=.011, P=.049, respectively). The mean fracture load of all crowns, regardless of the finish line design, was 1646 N. The fractured surface of the crown revealed adhesive failure and 3 types of cohesive failure (fracture of the Targis and Vectris, Targis fracture with a crack in the Vectris layer, and crushing without fracture). CONCLUSION: The marginal gaps were greater for the chamfer finish line specimens than in the shoulder finish line specimens. However, the fracture strength of the chamfer finish line specimens was greater than that of the shoulder finish line specimens.     

Safety and efficacy of a nightguard bleaching agent containing sodium fluoride and potassium nitrate.

OBJECTIVES: Transient sensitivity during bleaching is generally reported to affect 67% of patients. While most people tolerate this sensitivity, some find it impossible to continue treatment. The purpose of this study was to determine the safety and efficacy of an experimental, low-sensitivity bleaching agent. METHOD AND MATERIALS: Twenty-two participants bleached for a minimum of 6 hours per night over a 2-week period. The bleaching agent used, Experimental Product E, is a 10% carbamide peroxide gel containing potassium nitrate and sodium fluoride. Evaluations were performed at baseline and 1,2,13, and 26 weeks. Color change was measured using a value-ordered Vita classic shade guide and a colorimeter. Sensitivity of the teeth, gingiva, tongue, and/or throat was measured daily using a patient log. RESULTS: The median color change after 2 weeks was eight tabs. Approximately 36% reported sensitivity during the active whitening phase of the study. As a group, participants reported sensitivity during 13.7% of the total days spent whitening. CONCLUSION: Experimental Product E was shown to be safe. Participants experienced minor sensitivity during the active bleaching phase only. Experimental Product E was shown to be an effective bleaching agent for the subjects tested in this study.