The research study by Shultis et al. (1), which sought to establish a correlation between periodontal disease and overt nephropathy and end-stage renal disease in type 2 diabetes, raises several concerns.
First, while the analysis of the data attempted to preclude those with known risk factors, it fell short of accounting for many other common complications of diabetes and their direct and indirect impact on oral diseases. Diabetes risk factors and complications that might be associated with alveolar bone changes and were not considered in this research investigation are secondary hyperparathyroidism, musculoskeletal and rheumatologic disorders, bone metabolism alterations, eating disorders, nutritional disorders, self-care behaviors, psychosocial problems, and thyroid disease.
Second, the assessment and diagnosis of periodontal diseases in this study is inconsistent with the definition currently adopted by the American Academy of Periodontology. According to their position statement on the classification of periodontal disease, “to arrive at a periodontal diagnosis, the dentist must rely upon such factors as: 1) the presence or absence of clinical signs of inflammation (e.g., bleeding on probing); 2) probing depths; 3) extent and pattern of loss of clinical attachment and bone; 4) patient's medical and dental histories; and 5) presence or absence of miscellaneous signs and symptoms, including pain, ulceration, and amount of observable plaque and calculus.” The quantitative assessment of only attachment loss by measuring the distance between the cementoenamel junctions to the level of alveolar bone in the interproximal area of the tooth is not considered an acceptable means for the diagnosis and assessment of periodontal disease (2).
To a certain extent, dental researchers investigating the systemic relationships of periodontal diseases tend to downplay the complex mechanism, pathophysiology, and complications of diabetes. Much remains to be learned about the complex interrelationship between diabetes and oral diseases, and it is unrealistic for this type of research to encompass these factors. However, multiple factors that might influence the risk of oral health problems should always be acknowledged in performing research of this type. This will lead to a better understanding of the oral-systemic relationship that justifiably exists.
In summary, utilizing an assessment instrument that does not agree with the professional criteria for diagnosis of periodontal disease and equating the two is unacceptable. Failing to allude to these differences and an attempt to establish a relationship to chronic kidney disease and end-stage renal disease without acknowledging other possible mechanisms does not substantiate this study's conclusions.
