Influence of occlusal loading on peri-implant inflammatory cytokines in crevicular fluid: a prospective longitudinal study

Abstract

Objective The objective of the study was to evaluate the relation between occlusal loading and peri-implant crevicular fluid cytokine expression in patients with implant-supported complete fixed prostheses in both arches. Material and methods A prospective longitudinal clinical study was performed at a university clinic. Fifteen patients were selected and 11 were included. All patients had bimaxillary implant-supported complete fixed ceramo-metallic prostheses loaded at least 12 months before the beginning of the study. Allocation was established for each patient using a computerized occlusal analysis system. The test implant was the maxillary implant closest to the point of highest occlusal loading. The maxillary implant with least loading was the control implant. Occlusal adjustment was performed using a round diamond burr. This occlusal distribution was verified with the occlusal analysis system. Expression of cytokines from peri-implant crevicular fluid (TNF-α, IL-10, IL-6, IL-1β, IL-8) were recorded and analyzed in both test and control implants before (baseline: T0) and 2 (T1) and 12 months (T2) after occlusal adjustment. The Brunner-Langer non-parametric test was performed. Results At T0, the expression of IL-10 was significantly higher in the test group implants (p = 0.018). Between T0 and T1, the expression of all the cytokines decreased in the implants of both groups with statistically significant differences, except for TNF (p = 0.271). When comparing both groups at T1, there was no statistically significant difference in any of the analyzed cytokines. At T2, TNF-α suffered when compared with baseline, a statistical decrease in both study and control implants (p < 0,001). At T2, there were no statistically significant differences between groups in any of the cytokines analyzed. Conclusions Implants with higher occlusal load presented higher expression of IL-10 in peri-implant crevicular fluid. Occlusal adjustment produced a decrease in the expression of all the analyzed cytokines, both in test and control implants.

Cytokine expression in gingival crevicular fluid around teeth opposing dental implants and 3-unit fixed partial dentures in a cross-sectional study

“…Previous research has also noticed that occlusal stress triggers increases in the proinflammatory cytokines IL-1β, IL-6 and IL-17. In addition, another study showed that implants with a higher occlusal load presented higher levels of IL-10 in peri-implant crevicular fluid, which indicated the role of IL-10 in monitoring the occlusal force and counterbalancing the increased proinflammatory cytokines [ 28 ].…”

On Peri-Implant Bone Loss Theories: Trying To Piece Together the Jigsaw

“…But once again, the lack of a high degree of evidence studies is not to say that occlusal loads do not influence MBL and/or PI onset and progression. Within a still undefined “ideal threshold” (probably variable in each individual), occlusal forces transmitted to the bone may enhance both osteointegration and the features of the bone in close contact with the implant [ 108 , 109 ]. Probably, in absence of a clear definition of what exactly is “excessive occlusal load” [ 109 ] and given the complexity of exactly measuring in vivo the real strength and direction of occlusal loads in every single implant, it is difficult to clarify this point by now.…”

“…Within a still undefined “ideal threshold” (probably variable in each individual), occlusal forces transmitted to the bone may enhance both osteointegration and the features of the bone in close contact with the implant [ 108 , 109 ]. Probably, in absence of a clear definition of what exactly is “excessive occlusal load” [ 109 ] and given the complexity of exactly measuring in vivo the real strength and direction of occlusal loads in every single implant, it is difficult to clarify this point by now. Nevertheless, the loads transmitted through the implant-bone contact have lastly an influence on the RANKL/RANK/OPG pathway through the so-called “mechano-transduction phenomena” [ 108 ].…”

Oclusión bio-fisiológica protectora en prótesis implantosoportada

“…Dicho principio no parece poder establecerse en estos casos, ya que la mandíbula no se comporta igual que los huesos largos, ni las cargas que se producen en la cavidad oral son cargas estáticas. Otros trabajos mencionan que solo existe pérdida de hueso peri-implantario cuando existe una sobrecarga oclusal coexistiendo junto a inflamación de los tejidos peri-implantarios (58)(59) (60). Miyata remarca que la sobrecarga por sí sola no produce reabsorción de hueso peri-implantario, sino que se necesita que haya placa bacteriana e inflamación de los tejidos adyacentes para que se produzca daño biológico.…”