Nine studies were included in the review: three prospective cohort studies (n=118 patients); and six case series studies (number undeterminable). For three of the nine studies, data was utilised from only a subgroup of the total study population.
Six of the studies were rated as having a high risk of bias and three as having a medium risk of bias. Confounders were only adjusted for adequately in one study.
There was substantial variation in the way outcomes were defined and measured in the included studies.
The following is a summation of the review’s comprehensive outcome reporting:
Implant survival
This outcome was measured in five studies (two cohort studies and three case series studies). All studies except one reported better implant survival in the non-periodontitis patients than in the treated periodontitis patients; this was statistically significant in two studies.
Implant success
This outcome was measured in five studies (three cohort studies and two case series studies). All studies except one reported better implant success in the non-periodontitis patients than with treated periodontitis patients, although this was statistically significant in only one study.
Bone-level change
Measured in five studies (three cohort studies and two case series studies). All studies reported less bone loss in the non-periodontitis patients than in the treated periodontitis patients; this was statistically significant in one study.
Peri-implantitis
This outcome was measured in three studies (one cohort study and two case series studies). All studies reported lower rates of peri-implantitis in the non-periodontitis patients than with treated periodontitis patients; this was statistically significant in two studies.