Impact XP-endo finisher on the 1-year follow-up success of posterior root canal treatments: a randomized clinical trial.

OBJECTIVE: To evaluate the clinical relevance of using the XP-endo Finisher as a supplementary tool to improve the success of root canal treatment of posterior teeth with apical periodontitis, as assessed by 1-year follow-up. METHODS: A randomized clinical trial was conducted with 92 posterior teeth with apical periodontitis. Root canal treatment was performed using a single reciprocating file, with or without the supplementary use of the XP-endo Finisher. The status of apical periodontitis was assessed using the periapical index (PAI) at baseline and 1 year follow-up. Changes on PAI indicated that the lesions were healed, healing, or not healed. Successful treatments were defined as healed or healing lesions without clinical symptoms. Chi-square analysis and logistic regression were used for data analysis (α = 0.05). RESULTS: There was no significant difference in the distribution of healing status between the XP-endo Finisher group and the control group (p = 0.690). The success rates were also similar, with 81% in the XP-endo Finisher group and 78% in the control group. However, gender had a significant impact on success rates, with higher rates observed in females. CONCLUSIONS: The use of the XP-endo Finisher file as a supplementary tool did not affect the success rate of root canal treatment in posterior teeth with apical periodontitis. The findings indicate that the XP-endo Finisher file has limited clinical relevance in improving treatment outcomes for root canal treatment in posterior teeth with apical periodontitis. CLINICAL TRIAL REGISTRATION: The study protocol was registered in the Brazilian Clinical Trials Registry under identification number RBR-76w7cj (June 19, 2018).

Effect of laser photobiomodulation on the periodontal repair process of replanted teeth.

BACKGROUND/AIM: Tooth replantation is the optimal treatment in cases of avulsion. However, its success is limited due to the occurrence of external root resorption. The aim of this study was to assess the effect of laser photobiomodulation (LPBM) at λ808 nm and λ660 nm and of storage media on the periodontal repair process of replanted teeth in rats. MATERIAL AND METHODS: Sixty maxillary right incisors were extracted from sixty Wistar rats and randomly assigned to six groups (n = 10). Groups consisted of 10 teeth stored in paper napkins (PN), whole milk (WM), and soy milk (SM), for 45 min; and PNL, WML and SML, in which teeth were stored in the same storage media, but the root surface and the alveolus were treated with LPBM at λ808 nm before replantation, and the buccal and palatal mucosa of the alveolus were treated with LPBM at λ660 nm after replantation. Five rats from each group were euthanized after 15 or 30 days. The right hemimaxilla including the replanted incisor was removed and processed for histomorphometric analysis to assess root resorption areas, replacement root resorption, perimeter with ankylosis and periodontal repair, and areas of type I and III collagen deposition, using the ImageJ 1.50b software. Data were analyzed statistically by anova followed by Tukey's multiple comparison test (α = 5%). RESULTS: WM and SM showed smaller root resorption areas and higher collagen deposition in both experimental periods, and SM showed the largest perimeter of periodontal repair. LPBM reduced the occurrence of root resorption only in the PNL group, both at 15 and 30 days, and increased the perimeter of periodontal repair in all groups at 30 days. There was higher collagen deposition in the irradiated groups regardless of the experimental period. CONCLUSIONS: The LPBM protocol at λ808 nm and λ660 nm as well as whole milk and soy milk favored the periodontal repair process of replanted teeth in rats.

Methylene Blue-Mediated Photodynamic Inactivation Followed by Low-Laser Therapy versus Miconazole Gel in the Treatment of Denture Stomatitis.

PURPOSE: Photodynamic therapy (PDT) appears to be an effective method for the in vitro and in vivo inactivation of Candida spp., but no clinical trials in this context have yet been conducted. The aim of this study was to compare the effect of oral miconazole gel to PDT combined with low-power laser (LPL) therapy in the treatment of denture stomatitis. MATERIALS AND METHODS: Forty participants with clinical and microbiological diagnoses of type II denture stomatitis were randomly allocated to two treatment groups (PDT and miconazole gel), each with 20 individuals. The PDT group was submitted to one session of methylene blue-mediated PDT plus two sessions of low-laser therapy twice a week for 15 days. The miconazole group was submitted to the drug four times a day for 15 days. RESULTS: Forty percent of the patients achieved clinical and microbiological resolution of denture stomatitis after methylene blue-mediated photodynamic inactivation followed by low-laser therapy. The cure rate associated with miconazole was 80% (p < 0.05). Fifteen days after the end of treatment, the recurrence rate was 25% in patients treated with PDT combined with LPL therapy and 12.5% in patients treated with miconazole. CONCLUSION: Miconazole gel provides better results than a protocol combining methylene blue-mediated PDT and LPL therapy in the treatment of type II denture stomatitis.

Effect of laser photobiomodulation associated with a bioceramic cement on the repair of bone tissue in the femur of rats.

This study aimed to evaluate in vivo the effect of laser photobiomodulation associated with a repair cement (MTA Repair HP™) on the process of bone repair in the femur of rats, through histological and histomorphometric assays. Forty Wistar albino rats were randomly divided into four groups, with two periods of euthanasia - 15 and 21 days (n = 5 per period). Under general anesthesia, a bone defect was made in the left femur of each animal. In the LS (Laser) group, the defect was irradiated following the parameters: λ = 808 nm, P = 100 mW, ED = 80 J/cm2 per point, 22 s per point, E = 2.2 J per point. In the LM (MTA Repair HP™ + Laser) group, the defect was filled with MTA Repair HP™ and irradiated with laser in the same protocol of the LS group. In the MH (MTA Repair HP™) group, the defect was filled with MTA Repair HP™ without irradiation. In the CTR (Control) group, the bone defect received no treatment. At 15 days, the mean index of bone neoformation in the defect area was significantly lower in the CTR group as compared to the MH, LS, and LM groups. At 21 days, the LM group presented significantly greater bone neoformation than the MH group, without significant difference between LS and LM. Laser photobiomodulation therapy is promising as an adjuvant in the bone repair process, especially when associated with the use of biomaterials.

Laser phototherapy induces angiogenesis in the periodontal tissue after delayed tooth replantation in rats.

BACKGROUND: Laser phototherapy (LPT) has been suggested as a new therapeutic tool to improve the repair of replanted teeth. However, its effects and mechanism of action are not yet completely understood. OBJECTIVES: This study evaluated histologically the effect of laser phototherapy (LPT) λ808 and λ660 nm on angiogenesis in the periodontal tissue of replanted teeth in rats. MATERIAL AND METHODS: Twenty maxillary right incisors were extracted from twenty Wistar rats and randomly assigned to four groups (n = 5): PN - teeth were stored in paper napkin for 45 min; WM - teeth were immersed in 20 ml of UHT whole cow milk for 45 min; PNL and WML - teeth received the same treatment described for PN and WM, respectively, plus LPT at λ808 and λ660 nm. All root canals were prepared and filled with calcium hydroxide paste. The animals were euthanized 15 days after tooth replantation and angiogenesis was scored by blood vessel counting in the area of periodontal ligament and alveolar bone, using the ImageJ software. Data were analyzed statistically by ANOVA and Tukey's test (α = 5%). RESULTS: LPT at λ808 and λ660 nm caused significant increased angiogenesis on irradiated groups (PNL and WML) when compared to the non-irradiated groups (PN and WM) (p<0.05). There was no statistically significant difference between PN and WM as well as between PNL and WML (p>0.05). CONCLUSIONS: LPT is capable of stimulating angiogenesis in vivo in the periodontal tissue of replanted teeth. Key words:Angiogenesis, lasers, tooth avulsion, tooth replantation, wound healing.

Analysis of Aloe vera cytotoxicity and genotoxicity associated with endodontic medication and laser photobiomodulation.

This study aims to evaluate, in vitro, the effect of Aloe vera associated with endodontic medication, with or without laser photobiomodulation (FTL) irradiation in FP6 human pulp fibroblasts. The materials were divided into eight groups: CTR - control; CL - FTL alone; AA - Aloe vera with distilled water; AL - Aloe vera with distilled water and FTL; HA - calcium hydroxide P.A. with distilled water; HL - calcium hydroxide P.A. with distilled water and FTL; HAA - calcium hydroxide P.A. with Aloe vera and distilled water; HAL - calcium hydroxide P.A. with Aloe vera, distilled water, and FTL. The cytotoxicity was evaluated by MTT assay at 24, 48, and 72h and the genotoxicity by micronucleus test assay. This study was performed in triplicate. Data obtained in both tests were statistically analyzed by ANOVA and Tukey's tests (p≤0.05). Group AA presented high genotoxicity and low cytotoxicity. After 24, 48, and 72h, the group HAA significantly reduced the cell viability. Interaction with FTL showed slightly increase cell viability after 24 and 48h in groups CL and HL (p<0.001), despite the high genotoxicity in group CL and low genotoxicity in group HL. Group AL showed higher cell survival rate at 72h (p<0.05) and high genotoxicity (p<0.001). It was concluded that Aloe vera allowed higher cell viability in human pulp fibroblasts in the presence of calcium hydroxide or with FTL separately, but genotoxicity increased in these associations.

Tooth color change caused by photosensitizers after photodynamic therapy: An in vitro study.

This study aimed to perform an in vitro evaluation of the effect of photosensitizers used in photodynamic therapy (PDT) on tooth color change when used in combination with conventional endodontic treatment. Forty extracted human mandibular premolars were accessed and underwent root canal therapy and PDT. Photosensitizers were used in accordance with the experimental groups: MB (n=10) - PDT with Methylene Blue at 0.01%; TB (n=10) - PDT with Toluidine Blue at 0.01%; MG (n=10) - PDT with Malachite Green at 0.01%, at the concentration of 0.1mg/mL; and PC (n=10) - positive control, PDT with Endo-PTC cream stained with Methylene Blue at 25%. The samples were irradiated with 660-nm diode laser by means of a 330-µm-diameter optical fiber cable at a power density of 40mW for 120s. After light curing, the photosensitizers were removed from the specimens with 10mL sodium hypochlorite at 1%. A reflectance spectrometer was used for evaluation of color prior to and 60days after the experimental procedure based on the CIE L*a*b* system. According to ANOVA test, there were statistically significant differences between the experimental groups (p=0.003). Tukey's test showed a significant difference between PC and TB (p=0.008), as well as between MG and TB (p=0.009). However, there was no statistically significant difference between PC, MG (p=0.957) and MB (p=0.103). It was concluded that the use of PDT as an adjuvant to root canal therapy, using different photosensitizers, led to color change in tooth structure.

Accuracy of the dental pulp sensibility test using cold spray for the diagnosis of pulp diseases: an observational clinical study

The dental pulp sensibility test is one of the main auxiliary resources for the diagnosis of pulp pathologies, and its accuracy is still debatable. This cross-sectional observational study evaluated the accuracy of the pulp sensibility test (PST) using cold spray (1,1,1,2-tetrafluoroethane) for the diagnosis of pulp diseases and determined the effect of individual and clinical variables on the reliability of this test. The paper was designed following the STROBE statement. Sixty patients with indications for primary endodontic treatment were selected and examined from August 2017 to July 2018. Data collection was performed through interviews, clinical/radiographic examinations and the PST. The results of the cold test, along with data on sex, age, the tooth type regarding the root number, and the presence of restorations and caries, as well as the recent consumption of analgesics, were recorded. The presence of bleeding within the pulp chamber was used as the gold standard to compare with the clinical diagnosis and to identify the true-positive, false-positive, true-negative, and false-negative responses. The accuracy of PST achieved in subgroups of individual and clinical variables was compared using the chi-square test with a significance level of 5% (p < 0.05). The PST with the use of cold spray showed a sensitivity of 0.88, a specificity of 1.00, a positive predictive value of 1.00, a negative predictive value of 0.86, and an accuracy of 0.93. The accuracy of the cold spray was not affected by individual or clinical variables. The PST with the use of cold spray is an accurate and reliable method for determining the diagnosis of pulp diseases, especially in cases of pulp vitality or irreversible pulpitis.

Laser photobiomodulation effect on fibroblasts viability exposed to endodontic medications

Aim: The literature has not yet reported investigations about the effect of laser photobiomodulation (LPBM) over the cytotoxicity of drugs for endodontic treatments. Thus, the aim of this study was to evaluate, in vitro, the effect of the association between LPBM and intracanal medications on fibroblasts viability in different exposure times. Methods: Calcium hydroxide (Ca(OH)2) and iodoform (IO) were used pure or associated to LPBM. Eluates of medications were prepared and placed in contact with the cells in three different periods: 24h, 48h and 72h. Laser irradiation (emitting radiation λ 660nm, power density of 10mW, energy density of 3 J/cm²) has been performed in two sessions within a six hour interval, for 12s per well. After each experimental time, the colorimetric assay (MTT) has been performed. Statistical analysis was applied for Mann-Whitney test with 5% α error admitted test. Results: At 24h, the use of LPBM did not increase cell viability while after 72h cell proliferation was stimulated in the group without medications. LPBM application did not increase cell viability in Ca(OH)2 group and IO at any tested time. Ca(OH)2 cytotoxicity at 24h was higher than iodoform, while at 72h not difference was observed. Therefore, after 72 hours was no statistical difference between the IO and Ca(OH)2 groups. Conclusion: LPBM was able to increase cell viability in 72h in the group without medication, although no improvement was observed in the other groups. Thus, LPBM was not able to reduce the cytotoxic effects of the materials on fibroblasts in vitro

Assessment of carvacrol paste as endodontic medication associated with laser photobiomodulation in tissue repair: an experimental study in rats / Avaliação da pasta de carvacrol como medicação endodôntica associada à fotobiomodulação a laser no reparo: um estudo experimental em ratos

This study aimed to analyze the tissue reaction caused by carvacrol paste associated or not with laser photobiomodulation (LPBM) at λ660 nm in the subcutaneous tissue of rats. Sixty Wistar rats were divided into four groups and they received the following interventions: subcutaneous implantation of empty polyethylene tubes (CTR), implantation of tubes containing carvacrol paste (CVC), implantation of empty tubes and LPBM (LLLT), and implantation of tubes containing carvacrol paste and LPBM (CVCLT). The animals were euthanized at three, eight, and 15 days after surgery. The inflammatory reaction and fibroplasia were analyzed histomorphometrically. Significant differences among the groups were determined by ANOVA and Tukey's test (p<0.05). In the 3-day period, the CVCLT group had low inflammatory infiltration (p<0.01). In the 8- and 15-day periods, the LLLT and CVCLT groups presented a low amount of lymphocytic inflammatory infiltrate (p<0.01 and p<0.05). Regarding the formation of fibrous tissue, the CVC group had the highest formation of type III collagen in the 8-day period (p<0.001). In the 15-day period, the CVCLT group had a lower formation of type I collagen than the CTR and LLLT groups (p<0.05). The use of the carvacrol paste associated with photobiomodulation optimizes the inflammatory period and tissue repair.

Este estudo teve como objetivo analisar a reação tecidual causada pela pasta de carvacrol associada ou não à fotobiomodulação a laser (LPBM) a λ660 nm no tecido subcutâneo de ratos. Sessenta ratos Wistar foram divididos em quatro grupos e receberam as seguintes intervenções: implantação subcutânea de tubos de polietileno vazios (CTR); implantação de tubos contendo pasta de carvacrol (CVC); implantação de tubos vazios e LPBM (LLLT); implantação de tubos contendo pasta de carvacrol e LPBM (CVCLT). Os animais foram eutanasiados aos 03, 08 e 15 dias após a cirurgia. A reação inflamatória e a fibroplasia foram analisadas histologicamente. Diferenças significativas entre os grupos foram determinadas pelo teste ANOVA e teste de Tukey (p<0,05). No período de três dias, o grupo CVCLT apresentou menor infiltração inflamatória (p<0,01). No período de 8 e 15 dias, os grupos LLLT e CVCLT apresentaram menor quantidade de infiltrado inflamatório linfocitário (p<0,01 e p<0,05). Em relação à formação de tecido fibroso, o grupo CVC apresentou maior formação de colágeno tipo III no período de 8 dias (p<0,001). No período de 15 dias, o grupo CVCLT apresentou menor formação de colágeno tipo I em relação aos grupos CTR e LLLT (p<0,05). O uso da pasta de carvacrol associado à fotobiomodulação a laser otimiza o período inflamatório e o reparo tecidual.

Histological analysis of the periodontal ligament and alveolar bone during dental movement in diabetic rats subjected to low-level laser therapy.

OBJECTIVE: The purpose of this research was to evaluate the histological changes of the periodontal ligament and alveolar bone during dental movement in diabetic rats subjected to low level laser therapy (LLLT). METHODS: The movement of the upper molar was performed in 60 male Wistar rats divided into four groups (n=15): CTR (control), DBT (diabetic), CTR/LT (irradiated control) and DBT/LT (irradiated diabetic). Diabetes was induced with alloxan (150 mg/kg, i.p.). LLLT was applied with GaAlAs laser at 780 nm (35 J/cm(2)). After 7, 13 and 19 days, the periodontal ligament and alveolar bone were histologically analyzed. RESULTS: The mean of osteoblasts (p<0.01) and blood vessels (p<0.05) were significantly decreased in DBT compared with CTR at 7 days, whereas the mean of osteoclasts was lower at 7 (p<0.001) and 13 days (p<0.05). In DBT/LT, only the mean of osteoclasts was lower than in CTR (p<0.05) at 7 days, but no difference was observed at 13 and 19 days (p>0.05). The collagenization of the periodontal ligament was impaired in DBT, whereas DBT/LLT showed density/disposition of the collagen fibers similar to those observed in CTR. CONCLUSIONS: LLLT improved the periodontal ligament and alveolar bone remodeling activity in diabetic rats during dental movement.

Assessment of intracanal medications cytotoxicity on L929 fibroblast cells / Avaliação da citotoxicidade de medicamentos intracanais em fibroblastos L929

This study aimed to evaluate the cytotoxicity of intracanal medications on L929 fibroblast cells at different periods of observation. The following experimental groups were studied: calcium hydroxide with camphorated paramonochlorophenol and glycerin (CPG); iodoform with glycerin (IG); calcium hydroxide with iodoform and distilled water (CIW); iodoform with distilled water (IW); calcium hydroxide with distilled water (CW); Otosporin ® (OT); and a control group composed of cells and culture medium. Eluates were prepared from each group and placed in contact with 1 x 105 cells/well for periods of 30 minutes, 12, 24, 48 and 72 hours, 5 and 7 days. After each experimental period, a cytotoxicity test was performed using methyltetrazolium (MTT) and a spectrophotometer at an optical density of 570 nm to analyze cell viability. The ANOVA and Tukey test with a significance level of 5% was used to analyze the data. At 30 minutes and at 12 hours, all groups were equal to the control group. At 24 hours, there was greater cytotoxicity in the IG group than in the control group (P<0.001). At 48 hours, only the OT group was cytotoxic (P <0.001). At 72 hours and at 5 days, the most cytotoxic groups were CW and OT. At 7 days, the IW and CPG groups were the least cytotoxic (P <0.001). With respect to experimental time, significant differences between 24 hours and 7 days were observed in all groups. Otosporin® was the most cytotoxic medication, followed by calcium hydroxide with distilled water.

Este estudo teve como objetivo avaliar a citotoxicidade de medicações intracanais em células L929 de fibroblastos em diferentes períodos de observação. Os seguintes grupos experimentais foram estudados: hidróxido de cálcio com paramonoclorofenol canforado e glicerina (CPG); iodofórmio com glicerina (IG); hidróxido de cálcio com iodofórmio e água destilada (CIW); iodofórmio com água destilada (IW); hidróxido de cálcio com água destilada (CW); Otosporin® (OT); e um grupo controle composto por células e meio de cultura. Os eluatos foram preparados a partir de cada grupo e colocados em contato com 1 x 105 células/poço, por períodos de 30 minutos, 12, 24, 48 e 72 horas, 5 e 7 dias. Depois de cada período experimental, um teste de citotoxicidade foi realizado utilizando metiltetrazólio (MTT) e um espectrofotômetro a uma densidade óptica de 570 nm para analisar a viabilidade celular. A análise de variância e o teste de Tukey com nível de significância de 5% foi utilizado para analisar os dados. Em 30 minutos e em 12 horas, todos os grupos foram iguais ao grupo controle. Em 24 horas, houve uma maior citotoxicidade no grupo IG do que no grupo controle (P<0,001). Em 48 horas, apenas o grupo OT foi citotóxico (P<0,001). Em 72 horas e em 5 dias, os grupos mais citotóxicos foram CW e OT. Aos 7 dias, os grupos IW e CPG foram os menos citotóxicos (P<0,001). Com relação ao tempo experimental, foram observadas diferenças significativas entre 24 horas e 7 dias em todos os grupos. Conclusão: Otosporin® foi o medicamento mais citotóxico, seguido de hidróxido de cálcio com água destilada.

Effect of laser therapy on the inflammatory response induced by endodontic medications implanted into the subcutaneous tissue of rats / Efeito da laserterapia na resposta inflamatória induzida por medicamentos endodônticos implantados em tecido subcutâneo de ratos

Introduction: Endodontic medications contain toxic components that cause varying degrees of inflammation. Objective: This study evaluated the effect of laser therapy on the inflammatory response induced by intracanal medications implanted into the subcutaneous tissue of rats using a quantitative analysis of mast cells. Material and Method: Polyethylene tubes containing the medications were implanted in the dorsum of 60 rats divided into six groups, including HS (P.A. calcium hydroxide paste), HL (P.A. calcium hydroxide paste and laser therapy), HPS (P.A. calcium hydroxide paste with camphorated paramonochlorophenol), HPL (P.A. calcium hydroxide paste with camphorated paramonochlorophenol and laser therapy), IS (iodoform with saline) and IL (iodoform with saline and laser therapy). The animals were euthanized eight or fifteen days after surgery, and samples were removed and embedded in paraffin. Histological sections were stained with 0.2% toluidine blue for the quantification of mast cells. Analysis of variance (ANOVA) and Tukey's post-hoc test were applied to determine significant differences in the number of mast cells between groups (p<0.05). Result: There was a decrease in mast cells for the HL, HPL and IL groups when compared with the HS, HPS and IS groups at both time points. There was no statistically significant difference between the HPS and HPL groups at the eight-day time point. Conclusion: Laser therapy was effective at modulating the inflammatory response induced by endodontic medications by significantly reducing the number of mast cells. .

Introdução: Medicamentos endodônticos apresentam componentes tóxicos que provocam algum grau de reação inflamatória. Objetivo: Este estudo avaliou o efeito da laserterapia na resposta inflamatória causada por medicações intracanais, em tecido subcutâneo de ratos, por meio da análise quantitativa de mastócitos. Material e Método: Tubos de polietileno contendo as medicações foram implantados no dorso de 60 ratos, distribuídos em seis grupos: HS (pasta de hidróxido de cálcio P.A.); HL (pasta de hidróxido de cálcio P.A. e laserterapia); HPS (pasta de hidróxido de cálcio P.A. com paramonoclorofenol canforado); HPL (pasta de hidróxido de cálcio P.A. com paramonoclorofenol canforado e laserterapia); IS (iodofórmio e soro fisiológico) e IL (iodofórmio, soro fisiológico e laserterapia). Os animais foram eutanasiados oito e quinze dias após a cirurgia, as peças cirúrgicas foram removidas, processadas para inclusão em parafina e os cortes histológicos corados em Azul de Toluidina 0.2%, para quantificação dos mastócitos. A análise de variância (ANOVA) e o teste de Tukey post hoc foram aplicados para determinar diferenças significativas entre os grupos quanto ao número de mastócitos (p<0.05). Resultado: Nos grupos HL, HPL e IL houve uma diminuição de mastócitos em ambos os períodos experimentais em relação aos grupos HS, HPS e IS, porém não se observou diferença estatística significativa entre o grupo HPS e o HPL aos oito dias. Conclusão: A laserterapia foi eficaz em modular a intensidade da resposta inflamatória induzida pelos medicamentos endodônticos a partir da redução significativa na quantidade de mastócitos. .

Estudo preliminar da utilização de otólitos de Cynoscion acoupa sobre o processo de neoformação óssea em ratos / Preliminary study of using otoliths of Cynoscion acoupa upon the process of bone regeneration in rats

INTRODUÇÃO: Otólitos são concrescências calcárias presentes no ouvido interno de peixes. Por serem ricos em minerais considerados essenciais ao processo de mineralização óssea sobre uma matriz proteica (otolina), sugere-se que otólitos poderiam funcionar como biominerais. OBJETIVO: Avaliar a capacidade de regeneração de defeitos ósseos tratados com preparado gelatinoso estéril de otólitos. MATERIAL E MÉTODO: O experimento foi realizado com 20 ratos Wistar, distribuídos aleatoriamente em dois grupos, nos quais se realizou defeito ósseo na tíbia, sendo o grupo 1 (G1) experimental, cujas lojas ósseas foram preenchidas com preparado de otólitos, e o grupo 2 (G2) controle, cujas lojas ósseas não receberam tratamento adicional. Os animais foram sacrificados 14 dias após os procedimentos cirúrgicos; as tíbias foram removidas, fixadas em formalina a 10 por cento, descalcificadas em ácido nítrico a 5 por cento e processadas histologicamente. Antes dos sacrifícios, foram coletadas amostras sanguíneas para avaliação das dosagens séricas de cálcio (Ca) e fosfatase alcalina (Alkp). RESULTADOS: As secções histológicas revelaram que o trabeculado ósseo neoformado mostrou-se mais denso e com atividade osteorreabsortiva periosteal menos conspícua no grupo experimental. Entretanto, não demonstraram diferenças estatisticamente significativas na área de neoformação óssea entre G1 (1,9 ± 0,3 mm²) e G2 (1,5 ± 0,4 mm²) (p = 0,0617). Os parâmetros bioquímicos (Ca e Alkp) apresentaram-se dentro dos limites de normalidade. DISCUSSÃO/CONCLUSÃO: Os dados sugerem que os otólitos podem desempenhar papel adjuvante na dinâmica da regeneração óssea.

INTRODUCTION: Otoliths are calcareous concrescences present in the inner ear of fishes. Since they are rich in minerals considered essential to the bone mineralization process on a protein matrix (otolin), it has been suggested that otoliths may work as biominerals. OBJECTIVE: The objective in this study was to analyze the regeneration capacity of bone defects treated with sterile gelatinous otolith preparation. MATERIAL AND METHOD: The experiment was performed with 20 Wistar rats randomized into two groups, in which a bone defect was inflicted in the tibia. In group 1 (experimental), bone cavities were filled with otoliths. In group 2 (control), bone cavities did not receive any additional treatment. The animals were sacrificed 14 days after surgical procedures. The tibias were removed, fixed in formalin at 10 percent, decalcified in nitric acid at 5 percent and histologically processed. Before sacrifice, blood samples were collected to evaluate serum dosage of calcium (Ca2+) and alkaline phosphatase (Alkp). RESULTS: Histological sections revealed that the newly formed trabecular bone was denser and the periosteal reabsorptive activity was less conspicuous in the experimental group. However, there was no statistically significant difference in the area of bone formation between G1 (1.9 ± 0.3 mm²) and G2 (1.5 ± 0.4 mm²) (p = 0.0617). Biochemical (Ca2+ and Alkp) parameters were within normal range. DISCUSSION/CONCLUSION: These data suggest that otoliths may be an adjuvant to the dynamics of bone regeneration.

Effect of low-level laser therapy and mineral trioxide aggregate on alveolar bone repair

Aim: This study aimed to evaluate the effect of low-level laser therapy (LLLT) associated to mineral trioxide aggregate (MTA) on the alveolar bone repair process. Methods: Forty Wistar rats had the upper right incisor extracted and were assigned to 4 groups according to the treatment of the alveolar wound: G1 - no treatment (control group); G2 - sockets were filled with MTA; G2 - sockets were treated with LLLT(l780 nm, 40 mW, 16 J/cm2); and G4 – sockets were treated with LLLT and filled with MTA. The animals were sacrificed 14 days after the surgical procedures. The maxillas were removed, fixed in formalin, decalcified in 0.5% nitric acid and processed histologically. Results: In G1, there was bone formation on the bottom of the socket, but it was not noticeable on the superficial areas, as well as the presence of an intense granulation tissue. In G2, the bone trabeculae were irregular and thin, and were associated with intense vascular hyperemia and chronic inflammation. In G3, there was substantial formation of thick interwoven osteocyte-rich trabecular bone, with an evident osteoblastic rimming. In G4, it was observed an intense deposition of thin irregular bone trabeculae, but vascular hyperemia was quite distinguishable. Conclusion: LLLT was the most successful treatment to improve alveolar bone repair.