Palatal soft tissue thickness around dental implants and natural teeth in health and disease: A cross sectional study

BackgroundPrevious studies focused on the influence of buccal mucosa thickness on peri-implant bone loss and inflammation, with inconclusive results. We observed substantially thicker palatal mucosal tissues at peri-implantitis sites. Therefore, we hypothesize that thick palatal peri-implant mucosa may be associated with deeper pockets and disease severity. PurposeTo compare the thickness of the palatal tissue between natural teeth and implants in periodontal health and disease. MethodsAdult, non-smoker, healthy patients who visited our department for periodontal examination or treatment with restored implants in the posterior maxilla were recruited. Probing depth (PD), plaque index (PI), gingival index (GI) and radiographic measurements were recorded around implant and the contralateral tooth. Palatal tissue thickness was measured using a 30G needle that was inserted perpendicular into the mucosa at the bottom of the periodontal/peri-implant pocket and 3 mm coronally. Differences in the palatal tissue thickness between teeth and implants (in the same patient) was performed using t-test; as well as between peri-implantitis and non-peri-implantitis sites (among patients). ResultsSixty patients were included. Thirty-four implants were diagnosed with peri-implantitis and 26 healthy/mucositis implants with corresponding 24 healthy/gingivitis teeth and 36 teeth with attachment loss. Mean PD was higher around implants (4.47 +/- 1.57 mm) than teeth (3.61 +/- 1.23 mm, p = 0.001). The thickness of implants' palatal mucosa was higher than in teeth, at the base of the pocket and 3 mm coronally (4.58 +/- 1.38 mm vs. 3.01 +/- 1.11, p = 0.000; 3.58 +/- 2.15 vs. 1.89 +/- 1.11, p = 0.000, respectively). Mean palatal tissue thickness was 4.32 +/- 2.35 mm for the peri-implantitis group while only 2.61 +/- 1.39 in healthy implants, 3 mm coronal to the base of the pocket (p = 0.001). Palatal thickness at peri-implantitis sites was higher (4.32 +/- 2.35) compared to periodontitis sites (2.23 +/- 0.93), p = 0.000. Implant sites with palatal mucosa >4 mm (n = 32) had deeper mean pockets (5.58 +/- 1.98) compared with thinner (<= 4 mm) sites (n = 28) (4.48 +/- 1.18, p = 0.018). ConclusionThicker palatal tissue around implants is associated with deeper palatal pockets. Thick palatal tissue was found around implants diagnosed with peri-implantitis.