The aim of this study was to longitudinally evaluate alterations in the position of the periimplant soft tissue margin, occurring during a 2-year period after insertion of fixed prostheses. 41 patients, subjected to treatment with partial or full-arch implant supported fixed prostheses based on a total of 163 standard Brånemark oral implants, were included in the study. A baseline examination was performed at time of insertion of the prosthetic construction and involved assessments of plaque, mucositis, probing depth, bleeding on probing marginal soft tissue level, width of masticatory mucosa and marginal soft tissue mobility. All patients were re-examined after 6 months, and after 1 and 2 years, respectively. A regression analysis was performed to evaluate if alterations, occurring in the position of the periimplant soft tissue margin during the 2 years, could be predicted by various variables recorded at time of the installation of the fixed prosthesis. The descriptive analysis showed a slight decrease in mean probing depth (0.2 mm) and width of masticatory mucosa (0.3 mm) during the follow-up period. Apical displacement of the soft tissue margin mainly took place during the first 6 months of observation. Lingual sites in the mandible showed the most pronounced soft tissue recession, decrease of probing depth, and decrease of width of masticatory mucosa. The statistical analysis revealed that lack of masticatory mucosa and mobility of the periimplant soft tissue at time of bridge installation were poor predictors of soft tissue recession occurring during the 2 years of follow-up, but indicated in greater amount of recession in women than men, in the mandible than in the maxilla, at lingual than at facial sites and with increased initial probing depth. It was suggested that the recession of the periimplant soft tissue margin mainly may be the result of a remodelling of the soft tissue in order to establish "appropriate biological dimensions" of the periimplant soft tissue barrier, i.e., the required dimension of epithelial-connective tissue attachment in relation to the faciolingual thickness of the supracrestal soft tissue.

The aim of this study was to evaluate the soft tissue conditions at osseo-integrated oral implants in relation to the width of masticatory mucosa. Thirty-nine patients who had received a full-arch fixed bridge reconstruction > or = 10 years ago or a partial reconstruction > or = 5 years ago on a total of 171 implants ad modum Brånemark were included in the study. The examinations involved assessments of plaque, gingivitis, bleeding on probing, probing depth, width of masticatory mucosa and marginal tissue mobility. Simple correlation analysis as well as multiple regression analysis were performed to evaluate relationships between recorded parameters. The results showed that 24% of the sites were lacking masticatory mucosa, and an additional 13% of the implants had a width of less than 2 mm. Mobility of the facial marginal soft tissue, i.e., lack of an attached portion of masticatory mucosa, was observed at 61% of all implants. No major differences in the clinical parameters examined were found between sites with and without an "adequate" width of masticatory mucosa. Multiple regression analyses revealed that neither the width of masticatory mucosa nor the mobility of the border tissue had a significant influence on (i) the standard of plaque control or (ii) the health condition of the peri-implant mucosa, as determined by bleeding on probing. Hence, the study failed to support the concept that the lack of an attached portion of masticatory mucosa may jeopardize the maintenance of soft tissue health around dental implants.

A higher alveolar buccal bony crest resorption and a more apical soft tissue marginal position should be expected, when implants are surrounded with thin alveolar mucosa at the time of installation, independently of the thickness of the buccal bony crest.

Different patterns of sequential early healing were found at implants installed in healed alveolar bone or in alveolar sockets immediately after tooth extractions. However, three months after implant installation, no statistically significant differences were found for the hard- and soft-tissue dimensions.

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