Dados do Resumo

Título

Evaluation of the oral microbiome in patients using antiresorptive drugs and patients irradiated in the head and neck region

Introdução

Therapeutic modalities such as radiotherapy for head and neck cancer and the use of antiresorptive medications have a high potential to produce adverse side effects, especially osteonecrosis after tooth extractions. The pathophysiology of this effect is not yet fully understood; however, recent studies have shown changes in the oral microbiota after cancer treatment, which may be a local triggering factor for delayed alveolar repair and, consequently, susceptibility to the development of necrosis.

Objetivo

The aim of this study will be to evaluate the oral microbiota of patients irradiated in the head and neck region and using antiresorptive medications who underwent tooth extraction. We will characterize, quantify and compare the microbial populations from saliva and supragingival biofilm of irradiated patients, using antiresorptive medications and diagnosed with bone necrosis, using the bacterial 16S rRNA gene sequencing approach; in addition, to identify the microbial profile of these patients; and identify possible microorganisms in the microbiota that may be related to the protection or delay of alveolar repair.

Métodos

A prospective observational case-control study will be conducted with a total of 50 patients allocated into three groups (G1: patients who will undergo irradiated tooth extractions in the head and neck region or using antiresorptive medications; G2: patients diagnosed with oral bone osteonecrosis; G3: non-oncological patients, without comorbidities or systemic impairment). Patients will undergo intraoral clinical evaluation, salivary evaluation and quality of life. Three types of samples will be collected: saliva, biofilm, and necrotic bone area. Collection will occur at three times: before surgery, thirty days after and sixty days after. The samples will be stored in a freezer with temperature regulated at -20ºC and subsequently metagenomic analysis will be performed through the extraction, amplification and sequencing of the V3-V4 region of the bacterial 16S ribosomal RNA (rRNA) gene.

Resultados

We will seek to establish the relationship between the oral microbiota and the clinical outcome after the extraction procedure in patients irradiated in the head and neck region and using antiresorptive medications. We will identify and compare the microbiota of the post-extraction alveolar socket, and identify possible microorganisms that may be related to protection or delay in alveolar repair.

Conclusões

We will seek to identify for the first time the global image of the oral microbiota of patients susceptible to the development of necrosis, and to better understand the composition of the microbiome resident in the oral cavity of patients irradiated in the head and neck region and using antiresorptive medications, and with this, enable prevention and better therapeutic management for this side effect.

Palavras Chave

Oral microbiome; Bisphosphonate-associated osteonecrosis; Osteoradionecrosis