[The incidence of local plaque retentive factors in chronic periodontitis]

One of the leading local risk factors for chronic periodontitis is the presence of plaque retentive factors in the oral cavity. The main objective of the study was to assess how the local irritation and plaque retention caused by untreated carious lesions, subgingival and approximal overhanging crown margins can affect the attachment loss at patients with chronic periodontitis. The incidence of plaque retentive factors were evaluated on 200 panoramic radiographs randomly selected from the archive of the Department of Periodontology. On the radiographs each fully erupted tooth were studied under magnifying glasses (1:2 magnification), and the distance between CEJ and the most coronal bone level was measured with a ruler with mm scales. The quality of restorations were evaluated based on the approximal adaptation of their margins. During the clinical examination the presence of local plaque retentive factors were registered by tooth, and the radiological alveolar bone level were recorded around both the healthy and restored or filled teeth. Statistical analyzes were made with linear regression analysis and ANOVA. Only 177 out of the randomly selected 200 radiographs met the incursion criteria and could be evaluated. The average age of patients was 49.98 years and the average approximal bone loss was 5.439 mm, showing increasing tendency with age. The 177 patients had a total of 3618 teeth and 1407 teeth presented plaque retentive factors including 164 untreated approximal carious lesions, and 1243 faulty restorations with approximal overhangs or open margins. Radiographically 82.5% of the restorations had incorrect approximal marginal adaptation. The majority of the untreated carious lesions occurred in the molar as well as in the front regions. The average bone loss at the teeth with faulty restorations were higher than at the sound teeth. 113 patients had an average bone loss higher than >4 mm. In those patients the differences between sound and restored teeth were smaller than those in the groups of patients with mild bone loss. Nevertheless neither group showed statistically significant differences between restored and sound teeth. In mild to moderate periodontitis local plaque retentive factors, overhanging crown margins or carious lesions are decisive aggregating factors both in gingivitis and periodontitis, especially in the susceptible population. In severe periodontitis according to our data there were only minimal differences between the attachment level around sound teeth and teeth with faulty restorations and local plaque retentive factors.