Apical periodontitis and associated factors in a rural population of southern Brazil: a multilevel analysis.

OBJECTIVES: This study aims to evaluate the association between apical periodontitis (AP) and sociodemographic/clinical factors in a probability sample of individuals living in a rural area of southern Brazilian. MATERIALS AND METHODS: A cross-sectional study was conducted involving 584 non-edentulous adult individuals who had undergone a full-mouth radiographic survey. Periapical status was analysed using the periapical index (PAI). Endodontic status was evaluated considering the occurrence of voids in the filling material and the root filling length. Crown status was classified based on the presence of caries, restorations, and prosthetic crowns. Sociodemographic variables, frequency of dental care, and periodontal disease were also registered. The data were analysed using hierarchical multilevel Poisson regression analysis. The multilevel structure was composed of three models: sociodemographic variables, clinical variables, and clinical variables adjusted by sociodemographic variables (α = 5%). RESULTS: The prevalence of AP in the sample was 60.45%. AP was significantly associated with age, skin colour, schooling, periodontal disease, and frequency of dental care (P < 0.005). Among the 10,396 teeth evaluated, 868 (8.35%) had AP, which was significantly associated with tooth group, dental arch, crown status, and endodontic treatment (P < 0.005). CONCLUSIONS: The prevalence of AP was high in the population studied. An older age, black/brown skin colour, low level of schooling, infrequent dental care, severe periodontal disease, mandibular teeth, posterior teeth, inadequate crown status, and having undergone endodontic treatment were significantly associated with the outcome. Clinical relevance This study about a rural probability sample reinforces that AP is still a recurrent oral health problem.

High-fat diet effect on periapical lesions and hepatic enzymatic antioxidant in rats.

AIMS: To evaluate the effects of a high-fat diet (HFD) on the progression of apical periodontitis (AP), local inflammation, systemic antioxidant status, and blood lipid profile in rats. MAIN METHODS: Sixteen male Wistar rats were fed a standard diet (SD) or a HFD. At the sixth experimental week, the pulp chambers of the mandibular first molars were exposed to develop AP. A glucose tolerance test was performed the week before euthanasia. At the tenth experimental week, the animals were euthanized and the livers were collected to estimate catalase (CAT) and reduced glutathione (GSH) levels. Blood was acquired for biochemical analysis. The size of AP was estimated from radiographs and described as AP size-to-body weight ratio; inflammatory grade of AP was determined by histological analysis. KEY FINDINGS: At the end of the experimental period, the rats fed the HFD had 30% less weight (P < 0.0001) and higher blood glucose levels after 30 min of sucrose intake (P < 0.05) than those fed the SD. Animals from the HFD group had lower levels of CAT (P < 0.01), but the same was not observed in the GSH levels. Plasma insulin and total cholesterol were not affected by the diet. The rats fed the HFD presented greater AP than those fed the SD (P < 0.05). However, the local inflammatory infiltrate was similar in both groups. SIGNIFICANCE: The alterations promoted by the consumption of a HFD were not only observed systemically, but also locally, producing greater AP in rats than a SD.

Histopathological, Microbiological, and Radiographic Analysis of Antimicrobial Photodynamic Therapy for the Treatment of Teeth with Apical Periodontitis: A Study in Rats' Molars.

OBJECTIVE: The aim of this study was to evaluate in vivo, by histological and radiographic analysis, the response of apical tissues of rats' teeth with experimentally induced apical periodontitis, after one- and two-session endodontic treatment with and without photodynamic therapy (PDT). A microbiological analysis was also performed to verify bacterial reduction after each treatment. BACKGROUND DATA: Studies carried out in recent years highlighted the antibacterial potential of PDT when associated with conventional endodontic therapy in vitro. Although the antimicrobial effect of PDT is well-established, tissue response to PDT in teeth with apical periodontitis lacks studies. METHODS: Thirty-two rats' root canals were assigned to four groups: one session/PDT-[chemomechanical preparation (CMP)+root canal filling (RCF)]; two sessions/PDT- [CMP+calcium hydroxide (CH) for 14 days+RCF]; one session/PDT+ [CMP+PDT+RCF], and two sessions/PDT+ [CMP+PDT+CH for 14 days+RCF]. For microbiological evaluation, samples were collected before and after proposed treatments. For radiographic and histological analysis, the animals were euthanized after 28 days and the mandibles surgically removed. RESULTS: PDT associated with conventional endodontic therapy was able to promote significant bacterial reduction in root canals with induced apical periodontitis, but this reduction was not significantly different to conventional endodontic therapy alone. Although radiographic evaluation showed no significant differences, histological analysis showed lower scores for neutrophils/eosinophils in PDT-treated groups and macrophages/giant cells in CH groups. CONCLUSIONS: The use of low-level laser as light source did not promote major improvement on radiographic and histological repair, but since the number of inflammatory cells slightly decreased, it may optimize repair by modulating inflammatory process. PDT may be indicated as an adjunct to conventional endodontic therapy for teeth with apical periodontitis, in association with an interappointment dressing with CH, in an attempt to produce better conditions to stimulate repair.

Influence of Diabetes in the Development of Apical Periodontitis: A Critical Literature Review of Human Studies.

INTRODUCTION: The aim of this study was to perform a critical review of the literature that investigated the association between diabetes and apical periodontitis. METHODS: An electronic search was performed on PubMed/MEDLINE, LILACS, Scientific Electronic Library Online (Scielo), and Cochrane Collaboration databases. Human studies assessing the effect of diabetes in apical periodontitis development or in healing after root canal treatment were included. The outcome was apical periodontitis. RESULTS AND CONCLUSIONS: Nine articles were included. The results presented in the literature to date are still scarce and incipient, and the evidence for such an association is not yet conclusive. However, the published results trend to converge on a positive association between diabetes and a larger number of periapical lesions.

Simulation of soft and hard tissues and its effects on radiopacity of root canal sealers / Simulação de tecidos moles e duros e seus efeitos na radopacidade de cimentos endodônticos

PURPOSE: To simulate soft and hard tissues to assess radiopacity of three root canal sealers (Endofill, AH Plus and Sealer 26). METHODS: Five circular specimens (10x1 mm) were made and three experimental conditions were created. Situation #1: an aluminum step wedge allowed specimen being submitted to three digital radiographs. Situation #2: a retromolar mandibular segment containing the specimen was positioned between the digital sensor and X-ray machine. Situation #3: a soft tissue simulating material (utility wax - 30 mm) was associated with the mandibular segment. Mean gray values were measured using ImageTool 3.0 software. Two-way ANOVA and Tukey's test (α=0.05) was performed. RESULTS: Radiopacity increased when bone tissue was used (P<0.05), except for AH Plus. Situation #3 provided greater radiopacity (P<0.05). Radiopacity between most and least sealers decreased 44% when Situation #1 and #3 were compared. CONCLUSION: Simulated soft and hard tissues influenced the radiopacity of root canal sealers.

OBJETIVO: Simular tecidos moles e duros para avaliar a radiopacidade de três cimentos endodônticos. METODOLOGIA: Cinco espécimes circulares (10x1 mm) foram confeccionados e três situações experimentais foram criadas. Situação #1: espécime e uma escala de alumínio foram submetidos a 3 tomadas radiográficas digitais. Situação #2: um segmento retromolar de uma mandibula humana contendo o espécime foi posicionada entre o aparelho de raio X e o sensor digital. Situação #3: um simulador de tecido mole (cera utilidade - 30 mm) foi associado ao segmento mandibular. A média dos valores de cinza foi medida através do programa ImageTool 3.0. Análise de variância de dois critérios e Teste de Tukey (α=0.05) foram realizados para análise estatística. RESULTADOS: A radiopacidade aumentou quando tecido ósseo foi usado (P<0.05), exceto para o Ah Plus. A Situação #3 proporcionou os maiores valores de radiopacidade (P<0.05). Os valores de radiopacidade entre o cimento mais e o menos radiopaco diminuiu 44% quando as situações #1 e #3 foram comparadas. CONCLUSÃO: A simulação de tecidos moles e duros influencia a radiopacidade de cimentos endodônticos.

The effect of argon and nitrogen ion implantation on nickel-titanium rotary instruments.

INTRODUCTION: This qualitative study investigated the effect of N(2)(+) and Ar(+) ion implantation on morphologic alterations and fatigue resistance in Pro Taper S1 NiTi (Dentsply-Maillefer, Ballaigues, Switzerland) rotary instruments. METHODS: Instruments were divided into three groups: N(2)(+) implanted, Ar(+) implanted, and unmodified control group. All instruments were used to prepare five curved canals in epoxy resin blocks with brushing motion. The instruments were examined in a scanning electron microscope (SEM) before use, after first use, and after the fifth use. A more demanding cyclic fatigue test was undertaken, submitting the instruments to 15-second periods of continuous rotation inside the curved canals without a brushing motion. Crack formation was analyzed with the SEM, and the number of 15-second periods required to fracture each instrument was recorded. RESULTS: No significant morphologic alterations were observed in the instruments after the preparation of five canals. Crack density was similar in all groups. In the subsequent cyclic fatigue test, instruments implanted with nitrogen performed worse than those implanted with argon and the control group. Fracture faces show differences in the fracture modes. CONCLUSIONS: Ar(+) implantation improved the performance of S1 files moderately, whereas nitrogen ion-implanted files performed worse in the fatigue test. A reduction in file performance seems to be caused by nitrogen diffusion in the grain boundaries, instead of the desired improvement caused by titanium nitride formation.