Full- versus partial-mouth disinfection in the treatment of periodontal infections. Long-term clinical observations of a pilot study.

A classical treatment for chronic adult periodontitis consists of four to six consecutive sessions of scaling and root planing at a 1- to 2-week interval. Such a so-called "quadrant or sextant therapy" might result in a reinfection of a previously disinfected area by bacteria from an untreated region. The purpose of this study was to investigate, over an 8-month period, the clinical benefits of full-mouth disinfection within a 24-hour period in the control of chronic periodontitis. Ten adult patients with advanced chronic periodontitis were randomly assigned to a test and a control group. The control group received the standard scheme of initial periodontal therapy, consisting of scaling and root planing of the four quadrants was performed within 24 hours and immediately followed by a thorough supra- and subgingival chlorhexidine application to limit any transfer of bacteria. The latter involved tongue brushing with a 1% chlorhexidine gel for 60 seconds, mouthrinsing with a 0.2% chlorhexidine solution twice for 60 seconds, repeated subgingival irrigation of all pockets with a 1% chlorhexidine gel (3 times within 10 minutes), and mouthrinsing twice daily with a 0.2% chlorhexidine solution during 2 weeks. In addition, both groups received thorough oral hygiene instructions. The plaque index, gingival index, probing depth, gingival recession, and bleeding on probing were recorded prior to professional cleaning and at 1, 2, 4, and 8 months afterwards. Although the test group scored higher plaque indices than the control group, especially at months 2 and 4, the gingival index and bleeding tendency showed similar improvements with time. However, when the gingival/plaque ratio was considered, the latter was lower in the test group at all follow-up visits. For pockets > or = 7 mm, full-mouth disinfection showed a significantly (P = 0.01) higher reduction in probing depth at each follow-up visit with, at month 8, a reduction of 4 mm (from 8 mm to 4 mm), in comparison to 3 mm (from 8 mm to 5 mm) for the classical therapy. The increase in gingival recession in the full-mouth disinfection group remained below 0.7 mm, while in the control group it reached 1.9 mm after 8 months. This resulted in a gain of clinical attachment level of 3.7 mm for the test group versus 1.9 mm for the control group. A radiographical examination also indicated a superior improvement for the test group when compared to the control group. This pilot study suggests that a full-mouth disinfection in one day results in an improved clinical outcome in chronic periodontitis as compared to scalings per quadrant at 2-week intervals over several weeks.