Three different manufactures represented the implants included in the analysis. Seven subjects had Brånemark implants, four subjects had been treated with Astra Tech implants and one subject had a Straumann implant. Eleven subjects had periodontal supportive care performed by their hygienist or general dentist at a frequency of 6 months to once yearly. One subject reported sporadic visits. About 50% of the subjects performed dental home care twice a day including tooth brushing and interdental cleaning. Access for oral hygiene procedures was deemed acceptable for all the supraconstructions in both groups. None of the re-assessed patients reported prosthodontic retreatment after completing the previous study. Technical complications were observed in two supraconstructions, one with fractured occlusal screw (bridge screw) and one presented a lost filling of the access hole.

Three implants in the PTG group were lost during the study period.

Two implants had to be excluded due to technical complications, one from each group.

The results thus refer to 12 implants, evenly distributed between the two treatment modalities.

The PTG group showed a mean PPD of 4.3 mm (± 2.4) at the deepest site compared with 3.5 mm (± 1.2) in the OFD group. The baseline mean PPD was 6.5 mm (± 1.9) in the PTG group and 6.5 mm (± 2.3) in the control group and at 12 months 4.9 mm (± 1.8) in the PTG group and 4.4 mm (± 4.4) in the control group.

Five of the test implants and five of the control implants had at least one site with positive BoP score. Suppuration was demonstrated at five implants, two in the PTG group and three in the OFD group. The plaque scores were slightly higher in the OFD group at the final examination (Table 2).

The mean width of keratinized tissue for the PTG group and OFD group was 1.5 mm (± 1.0) and 2.8 mm (± 1.2), respectively. From baseline to the follow-up examinations presented here, the width of keratinized tissue decreased more in the PTG group as compared with the OFD group.