An Evaluation of Salivary Oxidant and Antioxidant Levels in Peri-implant Health and Disease

INTRODUCTION

Inflammatory lesions that develop in the tissues surrounding implants are generally referred to as peri-implant diseases. Peri-implant disease has two subgroups; peri-implant mucositis, which is reversible inflammatory lesion limited to the surrounding mucosal tissues, and peri-impantitis which is characterized by bone destruction around the dental implants. Peri-implant disease develops as a result of a balance problem between bacterial loading and host response around an implant that has been correctly secured by osseointegration. Bacteria produce tissue destruction directly, via toxic products, and indirectly, by activating host defense systems; in other words, by inflammation. Various types of molecules are formed in inflammatory lesions; these include reactive species such as free radicals (FR) and reactive oxygen species (ROS). ROS are physiological formations that are the endogenous sources of the mitochondrial electron transport chain seen in every living organism. ROS occur as a natural product of normal oxygen metabolism, and play an important role in cell signals and hemostasis. ROS increase during inflammation; hence, oxidizing conditions increase and cell structures are damaged. This condition is known as oxidative stress (OS). OS depends on an increase in FR production and/or a decrease in the protective mechanism (antioxidant status), and OS is defined as a balance problem between oxidants and antioxidants in the body.

Many studies support the idea that OS plays an important role in the etiology and severity of periodontal diseases.

The etiology and the pathogenic mechanism are similar in the periodontitis and peri-implant diseases processes. However, those studies indicating the effect of OS on peri-implant tissues have used quite small groups or small numbers of biomarkers. The results obtained have been contradictory.

Therefore, this study aimed to determine oxidant and antioxidant levels in the saliva of patients with various levels of peri-implant diseases and the relationship between oxidative stress and peri-implant diseases.

Inclusion criteria

• Adults aged 18 and older;
• Being systemically healthy; ,
• Being non-smokers;
• For dental implant groups, at least 1 osseointegrated implant;
• Dental implant applied by at least a specialist-level physician;
• Dental implants having the same surface and the same design;
• Correct prosthetic restoration of occlusal loading;
• Dental implant having been in function for at least 6 months.

Exclusion criteria

• Any history of medical conditions;
• Presence of active periodontal disease;
• Use of antibiotic or anti-inflammatory medications in the past 3 months;
• Pregnancy;
• Use of AO supplements;
• Smoking;
• Poor oral hygiene;
• Inflammation in the oral area;
• Presence of active caries;
• Presence of oral mucosal lesions such as oral lichen planus or recurrent aphthous stomatitis.