Pontoriero 1999.

Methods	1‐year follow‐up split‐mouth study including 4 parallel arms with 40 patients in total. Only 2 parallel arms evaluated. No drop outs at 1 year.
Participants	Patients in good general health and motivated for good oral hygiene. Teeth with PPD greater or equal to 6 mm and IBD greater or equal to 3 mm. In 2 groups, however, defects shallower than 3 mm were included and therefore were excluded from the present review. Age ranging between 32‐61; 15 males and 25 females recruited in 1 private practice.
Interventions	4 split‐mouth groups were included: (1) GTR with Guidor resorbable barriers versus flap surgery; (2) GTR with Resolut resorbable barriers versus flap surgery; (3) GTR with Gore‐Tex non‐resorbable barriers versus flap surgery; (4) Emdogain versus flap surgery and placebo. We analysed only groups (3) and (4) since in the other 2 groups defects shallower than 3 mm were included.
Outcomes	FMPS, BOP and for experimental teeth only: PAL, PPD, REC at baseline and 1 year. Tooth loss and postoperative infections. Additional intrasurgical measurements were taken. 1‐year data used.
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "The 40 subjects were randomly divided into 4 treatment groups including 10 subjects each: 3 membrane groups and one Emdogain® group".
Allocation concealment (selection bias)	Unclear risk	Author informed us that allocation to intervention group was concealed, but did not explain how.
Blinding (performance bias and detection bias) All outcomes	Low risk	Author informed us that both the outcome assessor and the patients were blinded to which site received which treatment.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Outcome data on PAL, PPD and REC are presented in Table 2: Result of GTR and Emdogain® therapy. Comment: No missing data. No drop outs.
Selective reporting (reporting bias)	Low risk	All pre‐specified outcomes are reported in Tables 2 and 4. Comment: Only data from the Gore‐Tex® and Emdogain® groups (3 and 4) are included in this review. Data from the other 2 groups had to be excluded on the basis of not meeting the 3 mm intrabony defect criterion. The author informed us that no teeth were extracted and no postoperative complication was reported. Changes in bone level and aesthetics were not evaluated as treatment outcomes.
Other bias	Low risk	No other source of bias can be identified.