Effects of boric acid on alveolar sockets filling after dental extraction in rats.

PURPOSE: After extraction, dental alveolus filling aims to reduce bone loss and maintain the alveolus volume during patient rehabilitation. Boric acid (BA) is a boron-derived compound with osteogenic properties and an interesting candidate for alveoli filling. This study aims to investigate the osteogenic capacity of the local application of BA in dental socket preservation. METHODS: Thirty-two male Wistar rats were submitted to upper right incisor extraction and randomly divided into four groups (n = 8): control group (no intervention), BA (8 mg/kg) socket filling, bone graft (Cerabone®, Botiss, Germany), and BA + bone graft socket filling. Animals were euthanized 28 days after dental extraction. MicroCT and histological analysis were performed to evaluate the newly formed bone on the dental alveolus. RESULTS: MicroCT analysis demonstrated that bone volume fraction (BV/TV), bone surface (BS), bone surface/bone volume ratio (BS/BV), bone surface density (BS/TV), trabecular thickness (Tb.Th), total bone porosity (Po-tot), and total volume of pore space (Po.V(tot)) from BA and BA + bone graft rats were significantly different from the control group. Histological evaluation displayed a delayed bone repair in BA rats, with the presence of connective tissue and inflammatory infiltrate. However, the BA + bone graft group demonstrated histological aspects like the bone graft animals, with less organized osteoblasts, suggesting inferior bone repair. CONCLUSION: Osteogenic capacity did not depend on the BA local application after 28 days of dental extraction. The presence of inflammation in the BA group can represent toxicity induced by the substance dosage used.

Antimicrobial and bone repair effects of boric acid in a rat model of dry socket (alveolar osteitis) following dental extraction.

BACKGROUND: Alveolitis occurs after dental extraction without blood clot formation, leading to an inflammatory process and bacterial contamination. Boric acid (BA) demonstrates anti-inflammatory, antimicrobial, and osteogenic properties. This study aims to evaluate the possible antimicrobial effects and bone repair of BA in a rat model of alveolitis (dry socket). METHODS: 33 male Wistar rats were submitted to the extraction of the upper right incisor and dry socket induction. They were first divided into two groups: dry socket (n = 17) and dry socket + 0.75 % BA (n = 16). Samples for the microbiological analysis were collected immediately after dental extraction, at the detection of clinical alveolitis, 7, and 14 days after BA application. For microCT and histological analysis, samples from euthanized rats were used in 14 and 28 days after alveolitis detection. RESULTS: Higher bacterial counts were found in 4-5 days after alveolitis induction, compared to the baseline in both experimental groups, decreasing significantly after 7 and 14 days of treatment with BA (P < 0.05). The microCT evaluation displayed increased bone volume, bone volume fraction, trabecular thickness, and bone mineral density in a time-dependent manner, regardless of BA treatment. On the other hand, the number of trabeculae and total bone porosity decreased over the 28 days of the experiment in the dry-socket group and both groups, respectively (P < 0.05). Histological analysis did not differ on bone repair in both experimental groups. CONCLUSION: This was the first report investigating the effects of BA in a rat model of alveolitis regarding microbiological and bone repair aspects. The BA local application decreased the total aerobic and facultative bacteria counts and does not seem to benefit the bone repair after alveolitis development. This study paves the way for more studies involving alveolitis and different BA applications.

Do resin cements influence the cuspal deflection of teeth restored with composite resin inlays?

The aim of this study was to evaluate the influence of different resin cements on the cuspal deflection of endodontically treated teeth restored with composite resin inlays. Sixty upper premolars were randomly divided into five groups (n=12): 1 - sound teeth; 2 - cavity; 3 - Rely X ARC; 4 - RelyX Unicem; 5 - SeT. The teeth from groups 2, 3, 4 and 5 received a MOD preparation and endodontic treatment. Impressions were made with vinyl polysiloxane and poured using type IV die stone in groups 3, 4 and 5. Inlays with composite resin were built over each cast and luted with the resin cements. A 200 N load was applied on the occlusal surface, and cuspal deflection was measured using a micrometer. After 24 h, cuspal deflection was measured again using a 300 N load. The Student t-test showed that there was no statistically significant difference between the 200 N and 300 N occlusal loads only for the sound teeth group (p = 0.389) and the RelyX ARC group (p = 0.188). ANOVA and Tukey'test showed that the sound teeth had the lowest mean cuspal deflection, differing statistically from the other groups (p<0.05). The highest cuspal deflections were obtained in the SeT group and the cavity group, with no statistical difference between them. Intermediate values were obtained in RelyX ARC group and RelyX Unicem group, which differed statistically. The self-adhesive resin cements RelyX Unicem and SeT showed less capacity to maintain the stiffness of the tooth/restoration complex than the conventional resin cement RelyX ARC.

Do resin cements influence the cuspal deflection of teeth restored with composite resin inlays?

The aim of this study was to evaluate the influence of different resin cements on the cuspal deflection of endodontically treated teeth restored with composite resin inlays. Sixty upper premolars were randomly divided into five groups (n=12): 1 - sound teeth; 2 - cavity; 3 - Rely X ARC; 4 - RelyX Unicem; 5 - SeT. The teeth from groups 2, 3, 4 and 5 received a MOD preparation and endodontic treatment. Impressions were made with vinyl polysiloxane and poured using type IV die stone in groups 3, 4 and 5. Inlays with composite resin were built over each cast and luted with the resin cements. A 200 N load was applied on the occlusal surface, and cuspal deflection was measured using a micrometer. After 24 h, cuspal deflection was measured again using a 300 N load. The Student t-test showed that there was no statistically significant difference between the 200 N and 300 N occlusal loads only for the sound teeth group (p = 0.389) and the RelyX ARC group (p = 0.188). ANOVA and Tukey'test showed that the sound teeth had the lowest mean cuspal deflection, differing statistically from the other groups (p<0.05). The highest cuspal deflections were obtained in the SeT group and the cavity group, with no statistical difference between them. Intermediate values were obtained in RelyX ARC group and RelyX Unicem group, which differed statistically. The self-adhesive resin cements RelyX Unicem and SeT showed less capacity to maintain the stiffness of the tooth/restoration complex than the conventional resin cement RelyX ARC.

O objetivo deste estudo foi avaliar a influencia de diferentes cimentos resinosos na deflexao de cuspides de dentes tratados endodonticamente e restaurados com inlays em resina composta. Sessenta pre-molares foram divididos aleatoriamente em cinco grupos (n=12): grupo 1 - dentes higidos; 2 - cavidade; 3 - Rely X ARC; 4 - RelyX Unicem; 5 - SeT. Os dentes dos grupos 2, 3, 4 e 5 receberam preparos cavitarios MOD e tratamento endodontico. Foram realizadas moldagens com silicone por adicao nos grupos 3, 4 e 5, seguido de vazamento de gesso tipo IV. Inlays em resina composta foram construidas sobre os modelos de gesso, sendo as inlays cimentadas com os cimentos resinosos. Uma carga de 200 N foi aplicada na face oclusal, e a deflexao de cuspide foi medida usando um micrometro. Apos 24 h, a deflexao de cuspide foi medida novamente sob carga de 300 N. De acordo com o teste t-Student, nao houve diferenca estatistica na deflexao de cuspides apenas para o grupo dos dentes higidos (p = 0.389) e o grupo do RelyX ARC (p = 0.188) quando comparada as duas cargas. De acordo com ANOVA e o tese de Tukey, os dentes higidos tiveram a menor media de deflexao de cuspides, diferindo estatisticamente dos outros grupos (p<0.05). A maior deflexao de cuspides foi obtida com o grupo SeT e o grupo cavidades, nao diferindo estatisticamente entre si. Valores intermediarios foram obtidos para os grupos RelyX ARC e RelyX Unicem, diferindo estatisticamente entre si. Os cimentos resinosos autoadesivos RelyX Unicem e SeT mostraram menor capacidade de manter a rigidez do complexo dente/restauracao em comparacao com o cimento resinoso RelyX ARC.

Metodologia para avaliação do efeito sistêmico e local da LLLT na osseointegração de implantes dentários em mandíbula de coelhos: nota prévia / Methodology protocol for assess systemic and local effects of LLLT on osseointegration of dental implants in the rabbits jaws

Objetivos: descrever a técnica cirúrgica e a sequência laboratorial utilizada na obtenção de dados por meio de dosagem hormonal, análise da frequência de ressonância (AFR), tomografia computadorizada de feixe cônico (TCFC), microscopia eletrônica de varredura (MEV), espectrometria por dispersão de energia (EDS) e análise histológica e histomorfométrica da região perimplantar pós-terapia com laser não ablativo (LLLT) em modelo experimental coelho. Materiais e método: foram utilizados 40 coelhos machos, raça Nova Zelândia, distribuídos em cinco grupos, sendo dois grupos designados controle (CI e CII) e três grupos designados experimentais (EI, EII, EIII). Os cinco grupos foram submetidos a coletas sanguíneas para dosagens de tri-iodotironina (T3), tiroxina (T4), cálcio e albumina, sendo o grupo CI considerado controle hematológico absoluto. Nos demais grupos (CII, EI, EII e EIII), foram realizadas a extração do incisivo inferior esquerdo e a colocação de um implante imediato com aferição da frequência de ressonância (AFR). Nos grupos experimentais, foi realizada laserterapia com três doses distintas (EI=70J/cm2, EII=35J/cm2, EIII=140J/cm2). Aos 45 dias, os animais dos grupos CII, EI, EII e EIII foram novamente submetidos à aferição da frequência de ressonância, foram mortos e tiveram suas mandíbulas dissecadas e avaliadas por TCFC, MEV e EDS. As mandíbulas foram incluídas, seccionadas e coradas com coloração de HE, picrosirius- -red e azul de toluidina para análise histomorfométrica da extensão linear de contato entre osso e implante (ELCOI) e a área óssea (AO) por meio de microscopia ótica. Considerações finais: apresenta-se um roteiro que pode servir de modelo para colegas pesquisadores.

Objectives: to describe surgical and laboratorial techniques used in an experimental rabbit model. The aim of the study was to obtain data using the following techniques: hormonal dosage, resonance frequency analysis (RFA), cone beam computed tomography (CBCT), scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), peri-implant histological and histomorphometric analysis after low-level laser therapy (LLLT). Materials and method: a total of 40 New Zealand male rabbits were divided into five groups. Two groups designated control (CI and CII) and three groups designated experimental (EI, EII, EIII). All groups underwent blood sampling for measurements of triiodothyronine (T3) and thyroxine (T4), calcium and albumin, with the CI group being considered absolute hematological control. For the other groups (CII, EI, EII and EIII) the extraction of the lower left incisor was performed followed by placement of an immediate implant with measurement of resonance frequency. The experimental groups were subjected to laser therapy with three different doses (EI = 70J/cm2, EII = 35J/cm2, EIII = 140J/cm2). Groups CII, EI, EII and EIII were subjected to the measurement of resonance frequency after 45 days, killed and the jaw was dissected to be evaluated by CBCT, SEM and EDS. Then, the samples were included, sectioned and stained with HE staining, picrosirius-red and toluidine blue for histomorphometric analysis by linear extent of bone-implant contact (BIC) and bone area (BA) using light microscopy. Final considerations: a technical sequence that can provide a model for fellow researchers was presented.