Delayed alveolar bone repair and osteonecrosis associated with Zoledronic Acid therapy in rats: macroscopic, microscopic and molecular analysis

Abstract Objective This study aims to evaluate bone repair and the development of the medication related osteonecrosis of the jaw (MRONJ) associated with the use of zoledronic acid in Wistar rats. Methodology 48 male Wistar rats were divided into four groups: ZA, treated with intraperitoneal zoledronic acid, 0.6 mg/kg every 28 days, totaling five doses; control (C), treated with 0.9% sodium chloride; ZA-surgical (SZA) and C-surgical (SC), submitted to extraction of the right upper molars 45 days after the first application. Alveolar bone repair was evaluated by macroscopic and histological analysis. Protein expression evaluations were performed by qPCR. Results Macroscopic evaluation showed that 91.66% (11) of the animals in the SZA group and 41.66% (5) from the SC group presented solution of epithelium continuity (P<0.05). All animals in the SZA group and none in the SC group had bone sequestration. The area of osteonecrosis was higher in the SZA group than in the SC group (P<0.05). In molecular evaluation, the SZA group presented changes in the expression of markers for osteoclasts, with increased RANK and RANKL, and a decrease in OPG. Conclusion The results highlighted strong and evident interference of zoledronic acid in bone repair of the socket, causing osteonecrosis and delayed bone remodeling.

Medidas lineares em radiografias panorâmicas digitalizadas, fornecidas por programa de imagem para planejamento na implantodontia: correlação e análise crítica / The linear measurementson digital panoramic radiographies obtained in two image softwares for presurgical implant: correlation and critical analysis

O objetivo da presente pesquisa foi avaliar, comparativa mete, as medidas lineares em radiografias panorâmicas obtidas no programa Planimp, desenvolvido para planejamento pré-cirúrgico em implantes, com as obtidas pelo método manual, utilizando um paquímetro digital. A amostra constou de 50 radiografias panorâmicas de pacientes edêntulos, nas quais foram marcados pontos de referência para delimitar 14 distâncias anatômicas em cada radiografia. As radiografias foram digitalizadas por meio de um scanner HP Scanjet 4C/T (Hewllett Pa ck a rd). As mensurações lineares das distâncias anatômicas foram realizadas pelo método manual (paquímetro digital) e pelo método digital (Planimp). Os dados obtidos foram submetidos à análise estatística por meio do teste de variância, com nível de significância de 5 por cento. Esta análise estatística mostrou que não houve diferença significante entre as medidas manuais e digitais. A partir dos resultados concluiu- se que o programa Planimp apresentou desempenho adequado para a calibração da imagem radiográfica, bem como para a mensuração de distâncias lineares.

The present study evaluated the linear measurements on panoramic radiographs obtained in image software for presurgical implant planning (Planimp) compared to the manual technique using a digital caliper. The sample comprised 50 panoramic radio graphs of edentulous patients, on which reference points were traced for delineation of 14 anatomical dimensions on each radiograph. The radiographs were digitized with a HP Scanjet 4C/T scanner (Hewllett Packard). Linear measurements of the anatomical dimensions were achieved by the manual method (digital caliper) and digital method (Planimp software). The data achieved were submitted to statistical analysis of variance, at a significance levelof 5 percent. This statistical analysis has not demonstrate any significant difference between the manual and digital measurements. The results allowed the conclusion that the Planimp software displayed proper performances for calibration of the radiographic image andfor measurement of linear dimensions.