The traditional clinical indicators of implant performance are mobility, pocket depth, keratinized tissue width, amount of bleeding, amount of plaque accumulation, and gingival appearance.
This report examines measurements of these variables at intervals of 1 to 2 months for 36 months for 27 implants in 11 rhesus monkeys. The implants were cylindrical porous-rooted titanium alloy and were placed in premolar and molar mandibular sites using a two-stage technique. The implants were used to support both single-unit and multiple-unit restorations. Examination of traditional plots of indicator values versus time revealed no readily observable trends either for individual implants or for pooled implant data. The assumption was made that each observation may be expressed in terms of the additive relationship between the mean response of the total group of responses for an individual, the effect of time, and the error associated with the measurements. The data were analyzed using a multivariate analysis of variance with a repeated measures design (MANOVA, SPSS Inc., Chicago, Illinois). The analysis provided a control on differences between individuals because the effect of time was measured relative to the average response of the individual.
The conclusions of this study are (1) that the technique applied can be useful in determining trends in the measured indicators and (2) that a difference can be observed between implants supporting single-unit restorations and those supporting multiple-unit restorations.