Outcomes of non-surgical periodontal treatment by dental hygienists in training: Impact of site- and patient-level factors

Objectives: To investigate the site- and patient-level factors that impact on the response to non-surgical periodontal therapy in patients with chronic periodontitis. Methods: A retrospective evaluation of clinical outcomes following non-surgical periodontal therapy delivered by dental hygienists in training was undertaken. Case notes from 195 patients with chronic periodontitis were reviewed and clinical data pre- and post-treatment abstracted. Patients were categorized as 'responders' or 'non-responders' according to defined outcome criteria, and the relationship between clinical and demographic variables and treatment outcomes was assessed. Results: Overall, there was a good response to the periodontal treatment. At deep sites (those with pretreatment probing depth ≥5 mm), the mean probing depth reduction was 1.6 ± 0.9 mm. Seventy-one (36%) patients were classified as non-responders (indicating that at least 30% of their deep sites did not improve by at least 2 mm following treatment). The non-responding group contained a significantly greater proportion of smokers (28%) than the responding group (16%). Plaque scores did not differ significantly between responders or non-responders either pre- or post-treatment. Regression analyses indicated that smoking status (odds ratio, OR: 2.04), mean pretreatment probing depth (OR: 1.49) and percentage of deep sites ≥5 mm at pretreatment (OR: 1.02) were significantly associated with response to treatment. Conclusion: This study supports the benefits of non-surgical therapy in the treatment of chronic periodontitis by dental hygienists in training. Better responses to treatment tend to be observed in non-smokers and in those with less advanced periodontitis at baseline.