ABSTRACT
BACKGROUND: Methotrexate (MTX) is an immunosuppressive drug, widely used in inflammatory disturbances including rheumatoid arthritis. However, there is no consensus regarding the effect of MTX on implant osseointegration. OBJECTIVE: The purpose of this experimental study was to investigate the effect of low dose MTX on Bone-Implant Contact (BIC) of dogs. METHODS: Six mandibular premolar teeth (bilateral) of 8 mature dogs were extracted. After 3 months of healing, 6 implants (bone level, resorbable blast media surface) were inserted into the mandible of each dog (3 in each side). Dogs were randomly divided into a study group (receiving 2.5 mg/week MTX orally, 3 times per week for 4 weeks) and a control group each containing 4 dogs. In the 1st week, postoperative BIC was evaluated in 4 dogs, two from each group. In the 4th week, reverse torque and BIC were evaluated in the remaining 4 dogs. Data were analyzed with two-way ANOVA test for 95% confidence interval. RESULTS: The reverse torque test of the 4th week, showed a satisfying osseointegration. Histopathologic evaluation revealed that the BIC was significantly higher in the control group in comparison to the MTX group in the 1st and 4th week. In addition, the BIC of both groups were significantly increased in the 4th week in comparison to the 1st week in both groups. CONCLUSION: MTX has the potential to interfere with osseointegration process.
ABSTRACT
BACKGROUND: In periodontal diseases, contamination of roots with bacteria and their active biologic agents and smear layer formation following periodontal treatments, prevents reattachment of periodontal cells. As a matter of fact biomodification of root surface and removal of smear layer and debris is critical for regeneration of periodontal structures. The aim of this study was to compare the efficacy of smear layer removal by citric acid, tetracycline-hydrochloride (TTC-HCL) and mixture of tetracycline and acid and detergent (MTAD). MATERIALS AND METHODS: In this in vitro and experimental study, 12 impacted third molars were sectioned from cervical enamel junction (CEJ) to mid-root area into four dentinal specimens (n = 48). Three groups were conditioned by citric acid 3%, TTC-HCL 50 mg/mL and MTAD by means of cotton pellets, which were changed every 30 s for 3 min. The control group was conditioned by distilled water. Images from scanning electron microscope (SEM) were examined by two different analyzers. Data was analyzed by Kroskal Wallis and Mann-Whitney statistical analysis. RESULTS: The mean of dentinal tubules diameter was the most in MTAD group and the least in TTC-HCL and this difference was statistically significant (P = 0.05). CONCLUSION: According to the present study, TTC-HCL could remove debris and smear layer but citric acid and MTAD had better debris and smear layer removal efficacy and demineralization effect in comparison with TTC-HCL.
