Table 2.

Quality assessment scores of included studies.

	Score	Comments (treatment providers not possible to be blinded in any study)
Boonen	20	Participants and assessors blinded throughout. Clearly defined outcome measures
Abane	20	Identical treatment modality apart from surgical technique. Significant number not included in analysis
Chareanc.	19	Assessors remained blinded to treatment, clear outcomes and assessment methodology
Kotela	20	Good standardised treatment programmes with blinded assessors.
Hamilton	17	Assessors blinded to the treatment group, identical treatment strategies (aside from implant) between the two groups.
Parratte	19	Assessors remained blinded. Standardised technique, participants potentially unblinded.
Pfitzner	20	Three different implants used in three different groups.
Roh	17	Comparable groups, clearly defined criteria. Neither participants nor assessors blinded after initial randomisation.
Victor	16	Good inclusion/exclusion criteria, participants/assessors not blinded after allocation
Woolson	19	CT scanning of accurate measurements of outcome measures, assessors blinded to treatment.
Yan	16	Good inclusion/exclusion criteria and defined outcome measures
Chotanaphuti	16	Standardized treatment protocol, clearly defined outcomes. Assessors not blinded.