Longitudinal Investigation Of Chronic Periodontitis During Maintenance Therapy

Periodontal disease is among the most common diseases that attack human beings, and meanwhile it is the main cause of tooth loss in adults. Chronic periodontitis is most likely to be met in clinical work compared to any other type of periodontal disease, thus needs paying much more attention to. It is important to study the characteristics of disease progression during therapeutic period for that it would do a great deal of good in guiding treatment regimen, arresting disease progression in time, monitoring disease relapse and so on. Researches have shown that non-surgical periodontal treatment can effectively halt disease progression, reduce pocket depth, gain attachment level, and hinder further bone loss. Thereafter to keep the periodontal supportive tissue unchanged in a reasonably long time, maintenance procedure plays a significant role. Patients who maintain regular periodontal maintenance intervals experience more pocket reduction, less attachment loss and lose fewer teeth than patients who receive less periodontal maintenance or none at all. Even after surgical treatment, patients may suffer continuous periodontal breakdown if they receive no maintenance care. The arising and progression of periodontal disease may vary between regions andraces. So far the single report on the longitudinal observation of maintenance therapy inland was carried out by Cao et al in 1994. However a fairly large-sampled long-term investigation cannot be achieved till now.The Objectives of our study is to investigate the characteristics of clinical parameters, X-Ray, and microorganism changes during maintenance therapy of chronic periodontitis. Methods: 22 patients with chronic periodontitis were enrolled in a 9-month maintenance care program after non-surgical periodontal therapy. Oral hygiene instructions together with supra- and sub-gingival scaling and root planing were carried out every 3 to 4 months. Clinical parameters including probing pocket depth (PPD), probing attachment level (PAL), and bleeding on probing (BOP) were recorded at baseline and each re-examination points. Numeral X-Ray panoramas were taken at baseline and the 9-th month to investigate the changes of alveolar bone height at clinically active sites(PAL loss ≥2 mm). Bone height and root length were measured and the alveolar bone level was expressed as the ratio of the two values. Comparing the before-and-after ratio one can tell whether there was any obvious change in bone height as had been detected in clinical probing. Sub-gingival dental plaques were collected at 3 active sites or deep pockets from each patient at the second and third re-examinations. The smears were dyed with 2% Congo red, and then suffocated by 36% hydrochloric acid. The detection rate of cocci, rods, and spirochtes were figured out by taking count of 200 bacteria under microscope. Results: Utilizing subject mean for analysis: PPD decreased for 0.44 mm, and PAL showed a positive change of 0.38 mm, BOP% dropped for 18.94%. The recoveries were mainly observed during the first 3 months. PAL gain was most pronounced at approximal sites, and averaged to 0.49 mm. Lingual surfaces were in the second place with the gainamounting to 0.30 mm.And the buccal surfaces were the least. The differences among these three sites were statistically significant. Utilizing individual site for analysis: (1) periodontal pocket: The composition experienced a distinct change when the shallow pocket(0-3 mm) proportion rose and the proportions of medium deep(4-5 mm) and deep(^6 mm) pockets went down throughout the interval. Sites with ^4 mm pockets at baseline exhibited a greater percentage of pocket deepening than initial shallow pockets. And posterior teeth manifested the similar trend when comparing with anterior teeth. (2) attachment level: About 82% of the sites remain unchanged during the maintenance period, while 4% exhibited a PAL loss and 13% gain. The incidence of active site averaged to 5.75%/year. Molars and upper premolars appeared to be the most likely teeth to suffer from periodontal breakdown. The incidences at buccal, lingual, and approximal sites did not show any significant difference. As the baseline pocket depth increased, there were more sites demonstrated more amount of PAL gain. (3) X-Ray examinations: No significant change of alveolar bone height was observed during the 9-month interval. (4) microorganism composition: Nor did any microorganism differences can be found between the active and non-active sites. Conclusions: Non-surgical periodontal treatment followed by regular maintenance therapy may stabilize or even improve the periodontal health in a fairly short period, but had limited effect on bone level changes.Based on these findings, the present study summarized some of the rules of disease progression through longitudinal observation of 22 chronic periodontitis patients. And successfully stabilized or even improved the clinical parameters of most sites, but failed to bring any increase in bone level.