Raman 2014.

Methods	Trial design: 2‐arm, multicentre, parallel‐design RCT Location: Malaysia Setting: Hospital Number of centres: 2, patients recruited from outpatient Diabetes Clinic of the University of Malaya Medical Centre, then treated at Periodontology Clinic at the Faculty of Dentistry, University of Malaya Recruitment period: Recruitment period not explicit, although states screening and treatment from May 2010 ‐ April 2011 Funding source: 2 research grants from University of Malaya (P0027/2009B and RG/11HTM)
Participants	Inclusion criteria: Moderate‐advanced chronic periodontitis; at least 12 teeth; 5 or more > PD 5 mm or > and attachment loss 4 mm or > in at least 2 quadrants which bleed on probing Exclusion criteria: Systemic antibiotic use in prior 4 months; pregnancy; current smoker; cardiovascular/cerebrovascular event in prior 12 months; diabetes medication change during study; non‐surgical periodontal therapy in prior 6 months; surgical periodontal therapy in prior 12 months Age at baseline: Overall 56.2 yrs (SD 8.1); Gp A: 57.7 yrs (SD 9.9); Gp B: 54.6 yrs (SD 6.2) Sex (M:F): Overall M20:F12; Gp A M11:F4; Gp B: M9:F8 Tobacco use: Current smokers excluded from participation Alcohol consumption: Not reported Diabetes type: All type 2 Duration since diabetes diagnosis: Overall: <7 yrs n = 7 (21.9%), 7‐12 yrs n = 8 (25.0%), >12 yrs n = 17 (53.1%); Gp A: <7 yrs n = 4 (26.7%), 7‐12 yrs n = 4 (26.7%), >12 yrs n = 7 (46.7%); Gp B: <7 yrs n = 3 (17.6%), 7‐12 yrs n = 4 (23.5%), >12 yrs n = 10 (58.8%) Metabolic control: Fair mean HbA1c at baseline Mean HbA1c at baseline: Gp A: 7.80 (SD 1.50); Gp B: 7.60 (SD 1.50) Antidiabetic therapy: Not reported fully. Only a quote: "All subjects who completed the study were on oral hypoglycaemic drugs" Other medical conditions: Not reported Other clinical investigations: Systemic hs‐CRP, GBI Number randomised: 40 Number evaluated: 32 (Gp A: n = 15; Gp B: n = 17)
Interventions	SRP + OHI (x 3) + adjunctive chlorhexidine mouthrinse versus OHI (x 3) Gp A (n = 20): Repeat OHI (modified Bass technique, soft‐bristled toothbrush, compact‐tuft toothbrush, interdental brush, floss (using TePe oral hygiene education set)) until PI <20%, followed by SRP (single visit, ultrasonic scaler, Gracey curettes) and 0.12% chlorhexidine mouthrinse (Hexipro, Evapharm, Kuala Lumpur, Malaysia) 3 x 15 ml p/d for 14 days. OHI repeated at each monthly visit Gp B (n = 20): OHI (modified Bass technique, soft‐bristled toothbrush, compact‐tuft toothbrush, interdental brush, floss (using TePe oral hygiene education set)). OHI repeated at each monthly visit Duration of follow‐up: 3 months
Outcomes	Primary: HbA1c at baseline and 3 months Secondary: PI, PPD, PAL (corresponds to CAL) at baseline, 2 months, and 3 months
Notes	Sample size calculation: 30 required (15 per arm; 80% power). Accounting for attrition, recruited 40 (20 per arm). Results confirm arms were sufficiently powered after accounting for attrition. Quote: "This gave a within group analyses power of 80% for the NSPT group [Gp A] and 88% for the OHI group [Gp B]" Data analysis: Per‐protocol SES: Ethnicity data provided. Overall: Malay n = 9 (28.1%); Chinese n = 8 (25%); Indian n = 6 (46.9%) Gp A: Malay n = 5 (33.3%); Chinese n = 4 (26.7%); Indian n = 6 (40.0%) Gp A: Malay n = 4 (23.5%); Chinese n = 4 (23.5%); Indian n = 9 (52.9%) Adverse events: Not reported HbA1c assessment method: Not reported. Assessed by private laboratory, using 15 ml venous blood Conflicts of interest: Authors declare no conflict of interests Trial ID: NCT01951547
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "All subjects were assigned via block randomisation to age matched NSPT and OHI groups. Following randomisation, baseline values for hs‐CRP and HbA1c were obtained"
Allocation concealment (selection bias)	Unclear risk	Not reported
Blinding of participants	High risk	Not possible
Blinding of clinical operator	High risk	States "not double‐blinded." Not reported further
Incomplete outcome data (attrition bias) All outcomes	High risk	Per‐protocol analysis: not all participants analysed in groups randomised to, regardless of intervention actually received Gp A: lost 5 patients. 2 due to medication change during study (exclusion criteria); 2 withdrew for unspecified reasons; and 1 unable to attend recall due to distance Gp B: lost 3 patients. 1 due to medication change during study; and 2 withdrew for unspecified reasons
Selective reporting (reporting bias)	Unclear risk	All outcomes fully reported on, except adverse events
Other bias	High risk	Quote: "..during the randomization of subjects, more participants with poor metabolic control were placed in the NSPT group. In the OHI group, there was equal distribution of participants with poor and good metabolic control"