Chlorhexidine for prevention of alveolar osteitis: a randomised clinical trial

Abstract Objective To determine the effectiveness of chlorhexidine 0.12% mouthwash (CHX) after tooth extraction for the prevention of alveolar osteitis (AO). Material and methods We conducted a double-blind randomised clinical trial stratified by risk factors. We enrolled a cohort of 822 patients who underwent dental extractions, and were considered to be at risk of developing AO (previous surgical site infection, traumatic extraction, and tobacco smoking). After extraction, patients were randomly allocated for CHX group or placebo group, matched by risk factors. The primary outcome was clinical diagnosis of AO: increasing postoperative pain for 4 d within and around the socket, and total or partial breakdown of the blood clot in the socket with or without bone exposure. Results Follow-up was completed by 744 participants (372 chlorhexidine and 372 placebo). We detected no significant differences between the two groups at baseline. After completed follow-up, risk factors were equally distributed between the two groups. Overall incidence of OA was 4.97%, in which 27 participants treated with placebo (7.26%) and 10 participants treated with CHX (2.69%) developed AO. CHX reduced the incidence of AO by 63% [Absolute Risk Reduction: 4.57 (95% CI 1.5-7.7), Number Needed to Treat: 21.88 (95% CI 13.0-69.3), Fisher's exact test: p=0.006]. No adverse effects were reported. Conclusion The use of chlorhexidine 0.12% mouthwash after tooth extraction is safe and effective in reducing the incidence of AO in high-risk patients.

Influence of local tetracycline on the microbiota of alveolar osteitis in rats

The aim of the present study was to evaluate the effects of local tetracycline on the occurrence of alveolar osteitis in rats, and on the microbiota associated to this infection. Forty Wistar rats were randomly assigned to 4 groups (n=10): I - the rats had the maxillary right incisor extracted and the alveolar wound did not receive any treatment; II - adrenaline and Ringer-PRAS were introduced into the alveolar wound; III - the alveolar wound was irrigated with sterile saline; and IV - the alveolar wound was irrigated with an aqueous solution of tetracycline. Microbial samples from the alveolar wounds were collected 2 days after surgery and inoculated on blood agar (with and without 8 µg/mL of tetracycline) and other selective media, and were incubated in either aerobiosis or anaerobiosis at 37ºC, for 2 to 14 days. It was verified that tetracycline reduced the occurrence of alveolar osteitis in the rats and caused significant changes in the microbiota of the surgical sites, decreasing the number of anaerobes and increasing the participation of tetracycline-resistant and multi-resistant microorganisms.

O objetivo do presente estudo foi avaliar os efeitos do uso tópico de tetraciclina sobre a ocorrência de alveolite em ratos e sobre a microbiota a ela associada. Quarenta ratos foram divididos, ao acaso, em 4 grupos (n=10): grupo I, realizou-se somente a extração do incisivo superior direito e a ferida alveolar não recebeu nenhum tratamento; grupo II, além da extração dental, soluções de adrenalina e Ringer-PRAS foram introduzidas no interior do alvéolo; grupo III, a ferida alveolar foi irrigada com solução salina estéril; grupo IV, a ferida alveolar foi irrigada com solução aquosa de cloridrato de tetraciclina a 10 por cento. As amostras dos alvéolos para processamento microbiológico foram coletadas dois dias após a realização das cirurgias e foram inoculadas em ágar sangue com ou sem 8 µg/mL de tetraciclina e em outros meios de cultura seletivos, incubadas em aerobiose ou anaerobiose, a 37ºC, de 2 a 14 dias. Verificou-se que a tetraciclina reduziu a ocorrência de alveolite e provocou uma modificação significativa na microbiota do sítio cirúrgico, levando a uma redução nas proporções ocupadas pelos microrganismos anaeróbios e uma elevação da participação de microrganismos resistentes à tetraciclina e outros antimicrobianos.