Analysis of Bone Repair and Inflammatory Process Caused by Simvastatin Combined With PLGA+HA+ßTCP Scaffold.

PURPOSE: This study evaluated the tissue and inflammatory responses to the use of simvastatin and poly(lactic-co-glycolic acid) + hydroxyapatite + ß-tricalcium phosphate (PLGA+HA+ßTCP) scaffold for bone repair. MATERIALS AND METHODS: Two defects of 5 mm in diameter were made in the calvaria of rats, which were shared into the following 6 groups: naive, sham, vehicle, PLGA+HA+ßTCP scaffold, simvastatin (4 mg/mL), and simvastatin with the scaffold. Tissue samples were collected at 1, 7, 15, 30, and 60 days after surgery. Inflammation was evaluated by interleukin-1 beta and tumor necrosis factor alpha quantification and by a hemogram, whereas bone repair was evaluated using densitometry and scanning electron microscopy. Data were statistically analyzed using ANOVA followed by post hoc tests (P < 0.05). RESULTS: There was an increased cytokine expression in the scaffold and simvastatin groups (P < 0.001 and P < 0.05, respectively) 1 day after surgery but no alterations on the hemogram were observed. It was found on bone tissue samples that 60 days after surgery all groups presented similar densitometry values and morphology characteristics, despite the occurrence of bone formation delay in the simvastatin group (P < 0.01). CONCLUSION: The use of simvastatin and PLGA+HA+ßTCP scaffold, associated or not, did not lead to improvement in bone repair.

Microbial reduction by two chemical-mechanical protocols in primary teeth with pulp necrosis and periradicular lesion - an in vivo study.

The objective of this study was to determine the efficacy of chemical-mechanical procedures of two endodontic protocols for septic content reduction of root canals from primary teeth with pulp necrosis and periradicular lesion. Twenty-four primary root canals with pulp necrosis and periradicular lesion were divided into two treatment groups (n=12): multiple-visit and single-visit protocols. Samples were collected using sterile paper points before and after endodontic cleaning followed by microbiological identification through checkerboard DNA-DNA hybridization. Statistical analysis was performed using Proportion Test for score=0 comparing the findings before and after treatment for each group (Wilcoxon's test) as well as the differences in scores between protocols (Mann-Whitney's test) (p<0.05). Data were expressed as prevalence (presence or absence) and estimate of the average count (x10(5) cells) of each species. Differences in proportions of score=0 prior to treatment were non-significant (p=0.415), demonstrating equivalence between groups. A significant increase in score=0 was detected after treatment for both groups (p<0.0001). Single-visit protocol achieved a significantly greater reduction in mean scoring following endodontic treatment (p=0.024). Both protocols were capable of significantly reducing septic content in root canals of primary teeth with periradicular lesion. Moreover, single-visit protocol showed greater efficacy in reducing endodontic infection.

Microbial profile of root canals of primary teeth with pulp necrosis and periradicular lesion.

PURPOSE: The purpose of this study was to assess the microbial content of root canals of human primary teeth with pulp necrosis and periradicular lesion. METHODS: Microbial samples were collected from 24 canals of children treated at a pediatric dentistry clinic. Microbiological identification was performed using checker-board DNA-DNA hybridization for 40 different bacteria. Data were analyzed per canal based on the mean count and frequency of each bacterial species. RESULTS: Detectable levels of bacterial species were observed for 35 probes (88%). The most frequent bacteria were Fusobacterium nucleatum sp. nucleatum, Fusobacterium periodonticum, Prevotella melaninogenica, Prevotella nigrescens, and Prevotella intermedia. Facultative species were identified in 20 root canals (83%), anaerobic species were identified in 24 root canals (100%), and aerobic species in 18 root canals (75%). Black-pigmented bacilli were found in 23 samples (96%). The number of different bacterial species detected per canal ranged from five to 33. CONCLUSION: Endodontic infection in primary teeth with pulp necrosis and periradicular lesion is multimicrobial, including aerobic, facultative, and anaerobic micro-organisms.

Medial canthal region as an external reference point in orthognathic surgery.

PURPOSE: The aim of this investigation was to evaluate the effectiveness of using the medial canthal region (MCR) as an external reference point to determine the vertical dimension during maxillary repositioning as planned in model surgery and predictive tracing. MATERIALS AND METHODS: The analyzed group consisted of 43 consecutive patients who underwent maxillary or bimaxillary orthognathic surgery. Before downfracture, the vertical height was established from the distance of the MCR to the incisal edge of the right upper central incisor (UCI). The vertical dimension was obtained with frequent measurements by use of calipers as desired during cephalometric tracing and model surgery. After rigid fixation, the vertical height was verified again. The UCI was traced from the postoperative cephalogram and predictive tracing onto a preoperative tracing. Repositioning of the maxilla and postsurgical movements of the UCI were registered at the horizontal and vertical planes. Comparison was made between the predicted maxillary position on the cephalometric tracing and the actual position, as well as between the planned maxillary position in model surgery and the actual position. RESULTS: The mean difference between the planned UCI position on predictive tracing and postsurgical position was 0.30 mm (SD, 0.21 mm; P > .05) in the vertical plane. The variation between the planned maxillary position in model surgery and the actual position was 0.37 mm (SD, 0.31 mm; P > .05) in the vertical plane. CONCLUSIONS: Good surgical accuracy in positioning the mobilized maxilla can be achieved by use of the MCR as an external reference point.

The prosthetic need WHO index: a comparison between self-perception and professional assessment in an elderly population.

The purpose of this study was to consider the criteria for establishing the need for prosthesis, by comparing the need perceived subjectively by a patient (self-perception) with that assessed by an examiner according to the WHO diagnosis criteria. The proposed domiciliary sample comprised 270 elderly (aged 60 years or older) residents in a municipality in southern Brazil. The interviews and oral examinations were conducted by two dentists following a period of training and calibration. The criteria used conformed to the WHO and FDI standards. Statistical treatment of data included bivariate and multivariate analysis using SPSS 10.0. Only five patients identified the need for a prosthesis when not identified by the examiner. In the case of 172 elderly subjects, there was agreement in the self-perceived and observed treatment needs. The need for prosthesis was found in 93 elderly subjects who did not perceive any need for prosthetic treatment. The multivariate analysis showed that the variables age, gender, residential area and form of service most sought after during their lives were significantly associated with a better self-perception of oral health. The professional criteria based on WHO guidelines differed from the self-perceived need. Elderly male subjects who lived in a rural area and were 70 years of age or more, who did not participate in third age groups, and who had not sought dental services for most of their lives were the least likely to perceive the need for prosthetic treatment, thereby underestimating their oral health needs.

Edentulousness and associated risk factors in a south Brazilian elderly population.

AIM: To examine the relationship between edentulousness and the socioeconomic and behavioural variables collected in a cross-sectional study of an elderly population. METHODS: The study was conducted on 277 elderly (60 years or older) in the municipality of Biguaçu, Southern Brazil. The oral examinations and questionnaires were conducted by two calibrated dentists. The criteria used followed the WHO and FDI standards. RESULTS: Prevalence of edentulousness reached 48.4%. A significant association was found in bivariate analysis for gender, satisfaction with appearance, time since last dental visit, the type of dental service sought in the last 5 years, educational level of the elderly and their children, and age of the elderly. In the multivariate analysis, gender, time since last dental visit and level of education of the elderly were significantly associated with edentulousness. CONCLUSIONS: Female sex and low educational level were the main risk factors for edentulousness in this population. Although various Brazilian studies suggest a decline in edentulousness in the country, methodologically robust research into edentulousness in Brazil is still limited, demanding further studies into this highly prevalent yet preventable health problem amongst the elderly.

Stages of moral development among Brazilian dental students.

This research study aimed to evaluate the level of moral and ethical development of first-year students in a dental school. The students were presented with a dilemma that touched on personal and conflicting values. In responding to the questions posed, they had to present their criteria for judgments and norms that directly influence their behavior. Answers were then analyzed, leading to the categorization of interviewees into five stages of moral development according to Kohlberg's moral development system. The first, lowest stage in Kohlberg's system was reached by 11 percent of students. Most interviewees (47 percent) were in stage two, where individuals are conscious of their own conflicting interests, but an individualistic and instrumental set of morals tends to regulate those interests. Thirty percent of interviewees were identified with stage three, and 8.3 percent were found in stage four, whose main characteristic is the perception of self as a member of society, thus integrating interpersonal perspectives. Only one student reached stage five, in which the person recognizes universal rights and establishes a hierarchy of priorities. No individuals were found in stage six of moral development. The level of moral development found was low for students at this level, which may compromise the optimal moral development of the future dentist. The low level of moral development found may jeopardize the work of the future professionals, their treatment of patients, and society as a whole.

Effectiveness of NaOCl alone or in combination with EDTA on the diffusion of hydroxyl ions released by calcium hydroxide paste.

AIM: To evaluate the effect of different irrigant solutions employed during removal and replacement of calcium hydroxide paste on the diffusion of hydroxyl ions through root canal dentine in vitro. METHODOLOGY: Thirty-five maxillary and mandibular human canines with straight and fully developed roots were used. After mechanical preparation up to 1mm short of tooth length, 30 canals were filled with calcium hydroxide paste and 5 canals were left empty; all teeth had their coronal accesses properly sealed. Teeth were placed in plastic containers with distilled water, and pH was read after 30 days when the paste from 20 teeth was renewed. After removal of the paste by endodontic instrumentation and irrigation with distilled water, canals were replenished with newly mixed paste in Group 1 and 2. In these groups, final irrigation was conducted with 5 mL of EDTA followed by 5 mL of NaOCl in specimens in Group 1, and 5 mL of NaOCl only in specimens in Group 2. In 10 teeth the paste was not replenished at 30 days (Group 3). All specimens were returned to the containers with fresh distilled water, and the pH was recorded after another 30 days. The differences between the first (30d) and second (60d) pH readings were calculated and submitted to analysis of variance and individual comparisons using the Scheffeé's test. RESULTS: Results of mean analysis on differences of pH readings showed that greater diffusion had occurred on specimens in Group 3. Individual comparisons using Scheffeé's test showed statistical significance between Groups 2 and 3, and equivalence between all other groups. CONCLUSION: It was concluded that the use of EDTA did not enhance diffusion of hydroxyl ions through root canal dentine.

Influence of the duration of treatment using a 10% carbamide peroxide bleaching gel on dentin surface microhardness: an in situ study.

This in situ study evaluated the influence of two home-use tooth bleaching regimes (1 hour/day and 7 hours/day) using 10% carbamide peroxide (Nite White Excel 2Z) on the surface microhardness of dentin over a 21-day period. Nine blocks of dentin derived from the teeth of subjects, each with at least two thirds molar in need of extraction, were obtained from the cervical region and submitted to surface-hardness analysis (Shimadsu HMV/2000), fixed to an intraoral palate device fabricated for each subject, and positioned (3 left side, 3 right side, 3 center) according to experimental group. During the bleaching period, casts bearing the whitening agent were applied to the blocks for 7, 1, and 0 hours, respectively (7 left side, 3 right side, 0 center). After the treatment period, the specimens were once again submitted to microhardness analysis, using the same equipment as before, and then analysis of variance and the Scheffé test were applied to the mean differences between the initial and final evaluations. The results demonstrated that the statistical difference between the 1-hour and 7-hour groups was not significant. However, the 7-hour group, when compared with the control group, demonstrated statistically significant differences with a reduction in microhardness. Despite the occurrence of mineral loss in the 1-hour and 7-hour groups, this difference was only 3.1% and 5.4%, respectively, which allows one to conclude that these values probably have no clinical significance.