Influence of occlusal loading on peri-implant clinical parameters. A pilot study

Comparative Evaluation of Implant-Protected Occlusion in Partially Edentulous Fixed Restoration Using Qualitative and Quantitative Assessment - A Prospective Clinical Trial

OBJECTIVES

To compare and evaluate the occlusal variability/discrepancy recorded using qualitative (articulating paper) and quantitative (T-scan) techniques in partially edentulous implant-supported restorations.

MATERIALS AND METHODS

A total of 20 patients in the age group of 25-61 yrs participated in this study. All the patients had more than one tooth replaced with implant-supported prosthesis. After three months of restoration, occlusion reevaluated was carried out using qualitative (articulating paper) and quantitative (T-scan). T-scan data were used to measure implant occlusion time, occlusion time, and the relative occlusal force (ROFs) on implant prosthesis. And the data were statistically evaluated.

RESULTS

The T-scan values showed high points on the implants in most of the patients, which could not be evaluated by that of articulating paper outcomes.

CONCLUSION

The occlusal harmony achieved from using qualitative analysis of articulating paper was not supported by the finding of the quantitative analysis (T-scan). Also the T-scan provided the time interval of occlusion of the implant-supported restorations, which would help in better defining the implant-protected occlusal.

CLINICAL RELEVANCE

The T-scan occlusal analysis system provides ROF and time intervals of occlusal contact. This allows accurate occlusal equilibration of implant-supported restoration according to implant protected occlusal concept.

Occlusal Indicators Used in Dental Practice: A Survey Study

Introduction

The function of the masticatory apparatus is complete when the dentition is intact with contact between the individual teeth and proper occlusion with the antagonists. For years, occlusal contacts have been studied to determine their exact location and describing various materials and methods for their registration such as paper foil, silk, and Shimstock foil. For years, occlusal contacts have been studied to determine their exact location and describe various materials and methods for their registration such as paper foil, silk, shim stock foil, the T-Scan system, and more recently the OccluSense system. The primary aim of the study was at evaluating which of the occlusal indicators is the most commonly used in practice, and the secondary aim was whether dentists are willing to use digital methods to examine occlusion.

Materials and Methods

The main primary information of the survey was collected by sending electronically anonymous questionnaires to 2014 dentists, randomly selected from all regions of the country. 228 questionnaires were filled in and returned. To achieve the goal of the study, the self-developed questionnaire was created and tested to survey the opinion about the use of occlusal indicators in dental practice. Each questionnaire contains questions about the sociodemographic and professional status of the people in the group and their opinion about the positives and negatives and the effectiveness of occlusal indicators.

Results

The obtained results confirm the statement that the most frequently used occlusal indicator in dental practice is the articulation paper. Articulation foil and silk are used less frequently than articulation paper. Of the listed quality indicators, Shimstock foil is rarely used in practice. Of the indicated quantitative indicators, the T-Scan system is more used than the OccluSense system. In the era of rapid technology development, the opinion and desire of dentists to increasingly want to introduce in their clinical practice quantitative methods are the digital diagnosis of occlusion.

Conclusion

In any dental practice, if technically possible, digital methods would be used, giving more accurate and reliable data on the registered occlusal contacts.

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

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.

Bone stability around dental implants: Treatment related factors

The bone bed around dental implants is influenced by implant and augmentation materials, as well as the insertion technique used. The primary influencing factors include the dental implant design, augmentation technique, treatment protocol, and surgical procedure. In addition to these treatment-related factors, in the literature, local and systemic factors have been found to be related to the bone stability around implants. Bone is a dynamic organ that optimises itself depending on the loading condition above it. Bone achieves this optimisation through the remodelling process. Several studies have confirmed the importance of the implant design and direction of the applied force on the implant system. Equally dispersed strains and stresses in the physiological range should be achieved to ensure the success of an implant treatment. If a patient wishes to accelerate the treatment time, different protocols can be chosen. However, each one must consider the amount and quality of the available local bone. Immediate implantation is only successful if the primary stability of the implant can be provided from residual bone in the socket after tooth extraction. Immediate loading demands high primary stability and, sometimes, the distribution of mastication forces by splinting or even by inserting additional implants to ensure their success. Augmentation materials with various properties have been developed in recent years. In particular, resorption time and stableness affect the usefulness in different situations. Hence, treatment protocols can optimise the time for simultaneous implant placements or optimise the follow-up time for implant placement.