The objective of this study was to determine whether temporary splinting of periodontitis-affected mobile teeth, prior to non-surgical mechanical therapy, affects treatment outcome by eliminating scaling and root planing-induced trauma to the teeth. Mandibular anterior teeth of 29 patients (15 females; 14 males; age range 30 to 48 years) with adult periodontitis were evaluated. Clinical measurements were performed at 4 sites per tooth including mesial, distal, buccal and lingual aspects at baseline, 3 and 6 months after treatment. The following clinical parameters were analyzed: plaque index (PI), gingival index (GI), bleeding on probing (BOP), pocket depth (PD), probing attachment level (PAL), gingival margin level (GML) and tooth mobility (TM). Patients were randomly divided into 3 groups: i) group 1 (n = 8) received scaling and root planing (SRP) only, ii) group 2 (n = 10) received scaling and root planing before splinting and iii) group 3 (n = 11) received scaling and root planing after splinting. Statistical analysis revealed that there were no significant differences among the groups for either bleeding on probing or probing attachment level values at any of the time intervals. At the end of the study, the greatest decrease in pocket depth was noted in group 2 (1.24+/-0.10 mm) which was thought to be the result of gingival recession (0.73+/-0.07 mm). Group 1 was the only group that showed reduction in tooth mobility at 3 months compared to baseline (1.67+/-0.55 PTV units). Group 3 displayed the least reduction in tooth mobility during the entire study period (0.26+/-0.44 PTV units). In conclusion, splinting of mobile teeth before SRP, and thereby elimination of potential SRP-induced trauma to the mobile teeth, did not show any adjunctive effect on healing when compared to splinting after SRP. Thorough debridement of root surfaces, even performed in the presence of increased mobility, resulted in improvements in clinical parameters, i.e. mechanical manipulation of mobile teeth during periodontal treatment did not affect clinical outcome negatively.