Pathogenic bacterial species - as causal relationship and risk factor in peri-implantitis progression

Introduction: The oral bacterial microbiota consists of 700 bacterial species, from which pathogenic bacterial species will be selected, as they initiate and maintain the infection of dental implants. The aim of the present study is to evaluate, by Odds Ratio, the causal relationship between the presence of pathogenic bacteria and mucositis/peri-implantitis, while establishing, by Risk Ratio, the extent to which pathogenic bacterial species may contribute to the unfavorable evolution of peri-implantitis. Materials and methods: The study group included 54 patients who were evaluated clinically and paraclinically seven days after the insertion of dental implants, and divided into three groups: with a favorable evolution, with mucositis and peri-implantitis. After the clinical examination, samples of peri-implant fluid and subgingival plaque were collected for bacteriological examination and included in a bacterial score consisting of five steps, depending on the pathogenicity of the identified bacterial species. Results and discussion: The Odds Ratio (72.2-bacterial score 3; 22.86-bacterial score 4) demonstrated the existence of a causal relationship between pathogenic bacterial species and mucositis/ peri-implantitis, while the by Risk Ratio (15.83-bacterial score 3; 15.90-bacterial score 4) showed that pathogenic bacteria represent an important risk factor in the unfavorable evolution of mucositis and peri-implantitis. Conclusions: The relationship between bacteria and infections following the insertion of dental implants is demonstrated by the high values of both Odds Ratio and Risk Ratio. Understanding the role that bacteria play in the etiopathogenesis of peri-implantitis is essential in developing strategies for the prevention, diagnosis and treatment of peri-implantitis.