Effects of green tea and bisphosphonate association on dental socket repair of rats.

OBJECTIVES: To evaluate the effects of green tea intake and zoledronic acid intravenous therapy on teeth socket repair. DESIGN: Sixty male albinus Wistar rats were divided into 4 groups: C-Control, intravenous (IV) 0.9% saline solution (SS), GT-1% green tea in drinking water and IV SS, BP-IV zoledronic acid (BP), and BP+GT-IV BP and 1% green tea. 0.035mg/kg of BP was administered every two weeks. After ten weeks, right upper molars were extracted and the green tea started to be offered for GT and BP+GT. After 7, 14, and 28days the animals were euthanized. RESULTS: Histopathology analysis revealed lack of socket repair in BP and BP+GT groups, which presented significant increased number of polimorphonuclear leukocytes at day 28, in comparison with C (p<0.05). No significant differences were detected between C and the experimental groups at the same period (p<0.05) when considering mononuclear leukocytes. Immunolabeling revealed that the association of BP and GT caused a slight disturbance in OPG/RANKL system and retarded Runx-2 labeling. Although strong TRAP labeling was observed, most of the positive cells in BP and BP+GT groups were not located on bone surface. CONCLUSIONS: Socket healing of rats treated with BP and regular drinking green tea presented no relevant differences in comparison to those treated with BP alone.

Short-term evaluation of a green tea extract-based mouthrinse / Avaliação de curto prazo de um enxaguatório bucal à base de extrato de chá verde

Introduction: mechanical hygiene is still the best method forthe maintenance of oral health and prevention of biofilm formation. However, mouthrinses have been increasingly used as an adjunct support especially for post-operatory conditions or when periodontal conditions require. In this way, a number of mouthrinses are available, presenting different active ingredients with predominant antimicrobial action. Objectives: the aim of the present study was to evaluate the topical action of a green-tea extract-based mouthwash on gingival tissue. Materials and Methods: a longitudinal double-blind comparison was performed with two groups of patients clinically evaluated and diagnosed as suffering from gingivitis (n= 40). The patients were divided into two groups, according to the mouthrinse used: GT - green tea (concentration of 20mg/ml), and P - placebo, 0.9% saline solution. Clinical examination of the mucosa, tooth staining, plaque and gingival indices were peformed before and 15 days after the continuous use of the products twice a day. Results: no mucosal or tasting alterations were found, neither tooth staining regardless the mouthrinse used. Statistical assessment did not detect differences on gingival indexes between the groups before and after mouthrinses use; however, plaque indexes were significant lower in patients of GT group, compared to the P group. Conclusions: the use of phytotherapic products with active ingredients should be investigated for biofilm control, responsible for the onset and progression of periodontal disease, as well as other various oral pathologies. Considering the period of evaluation pro-posed in this study, relevant decrease in initial phase of plaque for-mation could be observed with the green tea mouthrinse. Further long-term evaluation studies should be carried-out in order to eluci-date its continuous effects on oral structures.

Introdução: higiene mecânica ainda é o melhor método para a manutenção da saúde bucal e prevenção da formação de biofilmes. No entanto, enxagues têm sido cada vez mais usado como um suporte auxiliar especialmente para as condições pós-operatórias ou quando as condições periodontais exigem. Desta forma, um número de bochechos estão disponíveis, apresentando diferentes ingredientes ativos com predominante ação antimicrobiana. Objetivos: o objetivo do presente estudo foi avaliar a ação tópica de um bochecho à base de extrato de chá verde no tecido gengival. Materiais e Métodos: a comparação longitudinal, duplo-cego, foi realizada com dois grupos de pacientes clinicamente avaliados e diagnosticados como portadores de gengivite (n = 40). Os pacientes foram divididos em dois grupos, de acordo com o enxaguatório oral usado: CV - chá verde (concentração de 20 mg / ml), e P - placebo, solução salina a 0,9%. O exame clínico da mucosa, coloração dos dentes, índice de placa e índice gengival foram realizados antes e 15 dias após o uso contínuo dos produtos duas vezes por dia. Resultados: nenhuma alteração na mucosa ou de degustação foi encontrada, assim como não foi identificado modificação na coloração do dente. A Avaliação estatística não detectou diferenças no índice gengival entre os grupos antes e depois de usar enxaguatórios. No entanto, índice de placa inferior foi menor de forma significativa nos pacientes do grupo CV, em comparação com o grupo P. Conclusões: o uso de produtos fitoterápicos com ingredientes ativos deve ser investigado para o controle de biofilme, responsável pelo aparecimento e progressão da doença periodontal. Considerando o período de avaliação proposto, a redução correspondente na fase inicial da formação de placa pôde ser observada com o enxaguatório à base de chá verde. Além disso, estudos de avaliação de longo prazo devem ser realizados, a fim de elucidar seu efeito contínuo em longo prazo sobre as estruturas orais.

Low-level laser therapy enhances the expression of osteogenic factors during bone repair in rats.

The aim of this study was to evaluate the effects of low-level laser therapy (LLLT) on bone formation, immunoexpression of osteogenic factors, and biomechanical properties in a tibial bone defect model in rats. Sixty male Wistar rats were distributed into bone defect control group (CG) and laser irradiated group (LG). Animals were euthanized on days 15, 30, and 45 post-injury. The histological and morphometric analysis showed that the treated animals presented no inflammatory infiltrate and a better tissue organization at 15 and 30 days postsurgery. Also, a higher amount of newly formed bone was observed at 15 days postsurgery. No statistically significant difference was observed in cyclooxygenase-2 immunoexpression among the groups at 15, 30, and 45 days in the immunohistochemical analysis. Considering RUNX-2, the immunoexpression was statistically higher in the LG compared to the CG at 45 days. BMP-9 immunoexpression was significantly higher in the LG in comparison to CG at day 30. However, there was no expressivity for this immunomarker, both in the CG and LG, at the day 45 postsurgery. No statistically significant difference was observed in the receptor activator of nuclear factor kappa-B ligand immunoexpression among the groups in all periods evaluated. No statistically significant difference among the groups was observed in the maximal load in any period of time. Our findings indicate that laser therapy improved bone healing by accelerating the development of newly formed bone and activating the osteogenic factors on tibial defects, but the biomechanical properties in LG were not improved.

Effects of biosilicate(®) scaffolds and low-level laser therapy on the process of bone healing.

OBJECTIVE: This study aimed to investigate the in vivo tissue performance of the association of Biosilicate(®) scaffolds and low-level laser therapy (LLLT) in a tibial bone defects model in rats. BACKGROUND DATA: Many studies have been demonstrating the osteogenic potential of Biosilicate and LLLT. However, there is a need to investigate the effects of both treatments for bone consolidation. METHODS: The animals were divided into control group (CG), Biosilicate scaffold group (BG), and Biosilicate scaffolds plus LLLT group (BLG). Animals were euthanized after 15, 30, and 45 days post-injury. RESULTS: The histological analysis revealed that all the experimental groups showed inflammatory infiltrate and granulation tissue, at the area of the defect at day 15. After 30 days, CG still showed granulation tissue and bone ingrowth. Both Biosilicate groups presented newly formed bone and interconected trabeculae. At 45 days, CG showed immature newly formed bone. A more mature newly formed bone was observed in BG and BLG. On day 15, BG demonstrated a statistically higher expression of cyclooxygenase (COX)-2 compared with CG and BLG. No statistically significant difference was observed in COX-2 immunoexpression among the groups at 30 and 45 days. Similar expression of bone morphogenetic protein (BMP)-9 was demonstrated for all experimental groups at 15 and 30 days. At 45 days, the BMP-9 immunoexpression was statistically upregulated in the BLG compared with the CG and BG. No statistically significant difference was observed in the receptor activator of nuclear factor kappa-B ligand (RANKL) immunoexpression among the groups in all periods evaluated. Biosilicate groups presented a decrease in biomechanical properties compared with CG at 30 and 45 days post-surgery. CONCLUSIONS: Our findings suggest that Biosilicate presented osteogenic activity, accelerating bone repair. However, laser therapy was not able to enhance the bioactive properties of the Biosilicate.

Effect of low-level laser therapy on intramembranous and endochondral autogenous bone grafts healing.

The aim of this study was to evaluate the healing process of intramembranous (IM) and endochondral (EC) bone grafts under low-level laser therapy (LLLT). Male rabbits underwent onlay autogenous bone grafts (1 cm in diameter) retrieved from the calvaria and iliac crest and fixed on parietal bones, divided into four groups: Calvaria (C), Iliac (I), Calvaria + LLLT (C+L), and Iliac + LLLT (I+L). Animals from C+L and I+L Groups had their grafts exposed to LLLT (AlGaAs-808 nm, CW, 30 mW, 0.028 cm² average laser beam area), 15 s irradiation time (16 J/cm² per point-total of 64 J/cm² per session). After 7, 14, 30, and 60 days, grafts were retrieved and resorption pattern analyzed by means of morphometry and TRAP-positive osteoclasts detection. Differences in the resorption levels of iliac grafts were observed, presenting 40% in I group against 8% in I+L grafts at the 14th day of evaluation (P < 0.05). After 30 days, resorption was maintained at 41% in I group, whereas I+L presented 15% in the same period (P = 0.0591). No significant differences were noted in the rates of calvaria grafts resorption in all periods. A significant higher number of osteoclasts on the grafts' surface was observed in C+L Group at day 30, in comparison with C group. In I+L Group, prevalence of osteoclasts was marked at day 7 (P < 0.05) in comparison to I Group. In general, it was concluded that biomodulative effects of LLLT did not significantly affect healing and resorption processes of autogenous bone grafts from EC and IM origins.

Persistence of resinous cement residues in dentin treated with different chemical removal protocols.

The aim of this study was to evaluate the persistence of resin cement residues after dentin surface cleaning with different alcohol-based solutions or an essential oil (eucalyptol). Forty bovine teeth were sectioned in order to expose pulp chamber dentin to be washed with 1.0 mL of 2.5% sodium hypochlorite (NaOCl), followed by 0.1 mL of 17% EDTA application for 3 min, and final irrigation with 2.5% NaOCl. The specimens were air dried and resin-based cement was rubbed onto the dentine surface with a microbrush applicator. After 15 min, the surface was scrubbed with a cotton pellet and moistened with different dentin cleaning solutions, compounding the following groups: G1--95% ethanol, G2--70% ethanol, G3--70% isopropyl alcohol, or G4--eucalyptol. The dentin was scrubbed until the cement residues could not be visually detected. Sections were then processed for SEM and evaluated at × 500 magnification. Scores were attributed to each image according to the area covered by residual sealer, and data were subjected to Kruskal-Wallis at 5% significance. Eucalyptol promoted the most adequate dentin cleaning, although no statistical difference was detected amongst the groups (P > 0.05), except between the eucalyptol and 70% ethanol groups (P < 0.05). All the evaluated dentin cleaning solutions were unable to completely remove the cement residues from the dentin surface.