A quantitative method of measuring the microleakage of thermocycled or non-thermocycled posterior tooth restorations

This study quantified microleakage in restorations made with three packable resin composites-Solitaire, SureFil and P60; one hybrid resin composite-Z250 and an amalgam-Dispersalloy, with or without the thermocycling process. Sixty sound, freshly extracted human molars were sectioned mesiodistally, creating buccal and lingual blocks. One hundred blocks with the flattest surface were selected. Cylindrical cavities with a diameter of 1.85 +/- 0.05 mm and a depth of 1.5 mm were prepared with a special diamond bur. The blocks were randomly assigned to 10 test groups (n = 10): five restorative materials and two thermal stress groups (thermocycled groups at 3,000 cycles at 5 degrees C and 55 degrees C with a dwell time of one minute at each temperature, or non-thermocycled). After the thermocycling test, the samples were immersed in 2% methylene blue for 12 hours. The samples were ground and the powder prepared for analysis in an absorbance spectrophotometer. All the results were statistically analyzed by the Kruskal-Wallis test and the Mann Whitney test. For the non-thermocycled groups, the means (microg/ml) of microleakage were: Amalgam-4.279 (a); Solitaire-4.148 (ab); Z250-3.418 (abc); P60-3.184 (bc); SureFil-2.890 (c). For the thermocycled groups, the means were: Amalgam-7.572 (a); Solitaire-5.471 (a); Z250-4.330 (ab); P60-3.418 (bc) and SureFil-2.779 (c). Thermocycling analysis showed no significant differences between the thermocycled and non-thermocycled groups for each material tested. It was concluded that no test material prevented microleakage. Only SureFil and P60 showed leakage means significantly lower than amalgam, with SureFil showing lower leakage than Solitaire. P60 only showed lower leakage than Solitaire in the thermocycled groups and Z250 showed results similar to the others materials.     

Treatment of gingival fibromatosis associated with Zimmermann-Laband syndrome

BACKGROUND: Gingival fibromatosis is a rare condition characterized by a generalized enlargement of the buccal and lingual aspects of the attached and marginal gingiva. METHODS: This case report describes the periodontal management of a 13-year-old female patient with gingival fibromatosis associated with Zimmermann-Laband syndrome. The patient presented with gingival enlargement involving the maxillary and the mandibular arches, anterior open bite, and non-erupted teeth. Periodontal treatment included gingivectomy in all four quadrants. RESULTS: Histopathologic evaluation of the excised tissue supported the diagnosis of gingival fibromatosis. A significant improvement in esthetic appearance and eruption of the non-erupted teeth were obtained. The patient was referred for appropriate orthodontic treatment and has been closely followed for the earliest signs of recurrence of gingival enlargement. CONCLUSIONS: The successful therapy for gingival fibromatosis depends on correctly identifying the etiological factors and improving the impaired function and esthetic appearance through surgical intervention and adjunctive orthodontics. Maintaining treatment results depends on preservation of periodontal health.     

Immunolocalization of a human cementoblastoma-conditioned medium-derived protein

Little is known about the molecular mechanisms that regulate the cementogenesis process, because specific cementum markers are not yet available. To investigate whether a cementoblastoma-conditioned medium-derived protein (CP) could be useful as a cementum biological marker, we studied its expression and distribution in human periodontal tissues, human periodontal ligament, alveolar bone, and cementoblastoma-derived cells. In human periodontal tissues, immunoreactivity to anti-CP was observed throughout the cementoid phase of acellular and cellular cementum, cementoblasts, cementocytes, cells located in the endosteal spaces of human alveolar bone, and in cells in the periodontal ligament located near the blood vessels. Immunopurified CP promoted cell attachment on human periodontal ligament, alveolar bone-derived cells, and gingival fibroblasts. A monoclonal antibody against bovine cementum attachment protein (CAP) cross-reacted with CP. These findings indicate that CP identifies potential cementoblast progenitor cells, is immunologically related to CAP species, and serves as a biological marker for cementum.     

Viral RNA splicing and papillomavirus oncogenesis

Human papillomavirus (HPV) infection is an etiologic cause leading to development of cervical and other ano-genital cancers as well as a subset of oropharyngeal cancers.     

Plaque inhibitory effect of a 0.05% cetyl-pyridinium chloride mouth-rinse in a 4-day non-brushing model

To cite this article:
Int J Dent Hygiene 9 , 2011; 266–273 DOI: 10.1111/j.1601‐5037.2010.00490.x
García V, Rioboo M, Serrano J, O′Connor A, Herrera D, Sanz M. Plaque inhibitory effect of a 0.05% cetyl‐pyridinium chloride mouth‐rinse in a 4‐day non‐brushing model. Abstract: Objectives: Results from clinical studies evaluating the efficacy of the adjunctive use of cetyl‐pyridinium chloride (CPC) containing oral hygiene products have shown wide variability, probably due to differences in formulations. The objective of this study was to determine the inhibitory plaque effect of a 0.05% CPC mouth rinse in de novo plaque formation in a 4‐day non‐brushing experimental model. Materials and methods: The study was designed as a short‐term double‐blind randomized cross‐over experimental model aimed to compare three products: a negative control (similar to the test product, without active ingredients), a positive control (with 0.12% chlorhexidine and CPC) and the test product (with 0.05% CPC) in terms of plaque index, gingival inflammation and microbiological variables. Results: Plaque levels after 4 days were 2.88 for the positive control, 3.86 for the negative control and 3.60 for the test. Differences among groups on day 4 were statistically significant (P < 0.001). Gingival index showed comparable values at baseline (P = 0.745), and significant increases were observed, with the exception of the positive control. Total colony forming units showed comparable values at baseline (P = 0.125) and significant increases were observed only in the negative control. Conclusions: The tested 0.05% CPC mouth‐rinse is capable of inhibiting plaque formation.     

Peripheral T-cell subsets in patients with reticular and atrophic-erosive oral lichen planus

OBJECTIVE: Oral lichen planus (OLP) presents with various clinical forms that can be classified into 2 major types: reticular OLP and atrophic-erosive OLP. Our objective was to investigate immunologic differences between these 2 types. STUDY DESIGN: We investigated possible immunologic differences between 26 patients with reticular OLP and 26 patients with atrophic-erosive OLP. RESULTS: No differences were detected in serum Ig levels or complement levels. However, the mean proportions of CD4+CD45RO+ and DR+ lymphocytes were significantly higher in patients with atrophic-erosive OLP than in patients with reticular OLP, whereas the mean proportion of CD8+CD45RA+ lymphocytes was significantly lower in patients with atrophic-erosive OLP. CONCLUSION: These findings suggest that the 2 clinical types of OLP might have different immunopathogenic mechanisms.     

Dental caries experience in Mexican schoolchildren from rural and urban communities

OBJECTIVE: To compare dental caries experience in Mexican rural and urban settings. DESIGN: Cross-sectional samples of schoolchildren. SETTING: A school in Mexico City and a rural school in a remote area of the Oaxaca State in Southern Mexico. SAMPLE AND METHODS: A total of 347, 9- to 10-year-old schoolchildren (rural area, 131 children; urban, 216) was examined by two standardised dentists using the WHO 1987 criteria. OUTCOME MEASURES: Data were analysed in terms of central tendency measures and 95 per cent confidence intervals. RESULTS: Caries prevalence was 91.6 per cent in the urban area, and 54.4 per cent in the rural area (P < 0.05). DMFT in 10-year olds was 1.93 (sd 1.72) and 0.40 (sd 0.76) in urban and rural areas respectively (95 per cent CI 1.16-1.89). The entire DMFT/dmft indices in the rural group were made up of the decayed component. CONCLUSIONS: There is a large difference in the prevalence and distribution of dental caries between rural and urban Mexican children. Dental treatment background also differs markedly. Findings highlight the need to establish distinct preventative and rehabilitative treatment strategies tailored to meet the specific needs of different population groups.     

Bone defect formation during implant placement following alveolar distraction

PURPOSE: This retrospective study was designed to evaluate the volume of hard tissue generated at the time of implant placement in distracted alveolar bone. MATERIALS AND METHODS: All patients who underwent distraction osteogenesis between 2000 and 2003 were included. The preoperative bone height, amount of distraction performed, and presence or absence of complications affecting implant placement were recorded. The augmentation achieved was correlated with insufficient bone formation using the Spearman correlation and the Fisher exact test. RESULTS: The study included 43 implants placed in 17 cases of alveolar distraction. Of the 34 implants placed in bone augmented by 4.5 to 6.5 mm, bone defects were observed with 12. All 9 implants placed in ridges augmented by 7 to 10.5 mm demonstrated a bone defect. The "defect" and "no-defect" implant groups differed significantly with respect to preoperative bone height and amount of distraction performed (P < .001 for both). Significantly more defects were formed in bone augmented by > 25% compared to bone augmented by < 25% (P < .001). CONCLUSIONS: When considering distraction osteogenesis, augmentation of up to 25% of the initial bone height seems more predictable and less likely to be associated with complications at the time of implant placement. In distractions greater than 25% of the original height, additional treatment should be considered.     

One-year clinical evaluation of tooth-colored materials in non-carious cervical lesions

The purpose of this study was to assess the clinical performance of bonded composite (Excite/Tetric Ceram - Vivadent) versus a resin-modified glass ionomer cement (Vitremer - 3M) for restoring non-carious cervical lesions. A total of 70 restorations (thirty-five per material) were placed in 30 patients, 18-50 aged, by one operator. Rubber dam was employed in all cases, lesions were pumiced, enamel margins were not beveled, and no mechanical retention was placed. The restorations were directly assessed by two independent evaluators using modified-USPHS criteria for six clinical categories. The ratings for clinical acceptability restorations (alfa plus bravo) were as follows (Tetric Ceram/Vitremer): retention (86%/100%), marginal integrity (100%/100%), marginal discoloration (100%/100%), wear (97%/100%), postoperative sensitivity (100%/100%) and recurrent caries (100%/100%). Statistical analysis was completed with Fisher's exact or Pearson Chi-square tests at a significance level of 5% (P<0.05). Results showed that almost all restorations were clinically satisfactory with no significant differences between materials groups. Five restorations of Excite/Tetric Ceram failed. No restorations of Vitremer have yet failed.     

Two-year follow-up of a patient with oligodontia treated with implant- and tooth-supported fixed partial dentures: a case report

Dental implants have become an accepted treatment modality for aging patients with either completely or partially edentulous arches. However, growing patients with congenitally missing primary and/or permanent teeth often need dental implant treatment, even before puberty, for optimum functional and/or psychosocial development. From a developmental perspective, dental implants cannot accompany the physiologic differentiation of the alveolar bone because of the difference in anchorage between an osseointegrated dental implant and a tooth in bone. Nevertheless, reports in the literature suggest that dental implants can be used successfully in partially and completely edentulous arches affected by congenital disorders such as ectodermal dysplasia. In this case report, a multidisciplinary team approach, which included an orthodontist, an oral surgeon, and prosthodontists, in the treatment of a patient with oligodontia is discussed. The orthodontic and prosthodontic treatment sequence, growth analysis from age 14 to 18 years, and successful therapy of an implant associated with late failure is presented.