Cannizzaro 2010.

Methods	Trial design: multicenter, randomised, parallel group trial Location: Italy Number of centres: four (private dental practices) Recruitment period: February to November 2008 Funding source: Z systems partially supported this trial
Participants	Inclusion criteria: patients missing a single tooth with residual bone height of at least 10 mm and width of at least 5 mm allowing implant placement with an insertion torque of at least 35 Ncm Exclusion criteria: general contraindications to implant surgery, lack of opposite occluding dentition in the area intended for implant placement, acute infection in the area intended for implant placement, immunosuppression or immunodepression, untreated periodontitis, poor oral hygiene and motivation, irradiation in the head or neck area, bruxism, under treatment or past treatment with intravenous amino‐bisphosphonates, uncontrolled diabetes, pregnant or lactating, substance abuse, psychiatric disorders or unrealistic expectations, participation in other clinical trials interfering with present protocol, having been referred only for implant placement or unable to be followed for at least one year, requiring the use of a membrane at implant placement, implant sites subjectively evaluated as being characterised by soft bone quality Age at baseline: occlusal 38 (918‐54); non‐occlusal 39 (26‐55) Gender: M17/F23 Number randomised: 40 Number evaluated: 40
Interventions	Comparison: Occlusal versus non‐occlusal immediate loading Gp A (n = 20) Immediate loading: (Occlusal) Single implants immediately restored the same day with acrylic single crowns in occlusion Gp B (n = 20) Immediate loading: (Non‐occlusal) Single implants immediately restored the same day with acrylic single crowns not in occlusion Permanent ceramic crowns were cemented after 4 to 5 months in both groups Z‐Look3® (Z‐System, Oensingen, Switzerland) one‐piece zirconia sand‐blasted screws were used Duration of follow‐up: 1 year
Outcomes	Prosthesis/implant failures, marginal bone levels, complications 1‐year data used
Notes	Sample size calculation: sample size calculation reported and states that the original intention was to recruit 80 patients in each group to detect a difference between a proportion of 0.999 and 0.920 (patients experiencing at least one implant failure)
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Reported in the article: "A computer generated restricted randomisation list was created. Only one investigator (ME), who was not involved in the selection and treatment of the patients, knew the randomization sequence and had access to the randomization list stored in a pass‐word protected portable computer"
Allocation concealment (selection bias)	Low risk	Reported in the article: "The randomised codes were enclosed in sequentially‐numbered, identical, opaque, sealed envelopes. Flap closure was obtained with vicryl 4.0 and the envelope containing the randomisation code was opened to disclose patient allocation........ Envelopes were opened sequentially after the implants were placed. Therefore, treatment allocation was concealed to the investigators in charge of enrolling and treating the patients"
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Reported in the article: "One dentist (CT) who treated 10 patients performed all radiographic assessments without knowing group allocation for the patients of the other 3 centres, therefore the outcome assessor was blinded for 30 out of 40 patients........ " Author replied that: "implant success was assessed by blinded outcome assessors at each centers"
Incomplete outcome data (attrition bias) All outcomes	Low risk	All data presented
Selective reporting (reporting bias)	Low risk	All outcomes appear to be presented
Other bias	Low risk	None detected