Straalen, M. van (Matthijs) (2017) Digitale occlusie analyse bij implantaatgedragen kronen in de posterieure regio. thesis, Dentistry.
Full text available on request.Abstract
Background: Occlusal overload is often regarded as one of the main causes for biomechanical failure of the implant supported crown. However, current methods of occlusal analysis used in clinical practice do not provide any valid indication of occlusal load. Establishing an appropriate occlusion on the implant supported crown plays a vital role in controlling occlusal forces. The level of harmony between static and dynamic occlusion determines the applied occlusal forces during functional activity. It must be emphasized that dental implants react in a different fashion to occlusal force than teeth. To review the relation between occlusion and biomechanical failure of the implant supported crown it is first warranted to objectively measure the distribution of occlusal force and contact timing in patients with an implant supported crown. The following guidelines for a well-maintained and controlled implant-specific occlusion concept have been proposed: a) Bilateral simultaneous contact and evenly distributed occlusal force b) No premature contacts c) Infraocclusion d) Lateral excursive movements without working/non-working interferences. Objective: The main purpose of this study is to digitally analyze static and dynamic occlusion with the T-Scan® Novus (Tekscan, South Boston, USA) in patients with an posterior implant supported crown and to verify if the results of the T-Scan meet the guidelines for implant-specific occlusion. Also, a possible correlation between a quantifiable time-delay, such that the natural teeth occlude prior to the implant prosthesis, and the applied occlusal force on the implant supported crown in maximum intercuspation (MIC) is investigated. A secondary objective was to assess the interrater reliability of the T-Scan Novus. Methods: This cross-sectional study was conducted at the Dentistry and Oral Hygiene department of the University Medical Center of Groningen. Patients that had received a posterior implant-supported crown that had been in function for approximately 1 year were included. The T-Scan Novus was used to record static and dynamic occlusion for each subject. The distribution of force in MIC and the corresponding load to occlusal contact on the implant-supported crown was equilibrated. The following occlusal parameters were also recorded for the implant supported crown: initial contact, time-delay and presence of working/non-working side interferences during lateral excursions. The intraclass correlation coefficient (ICC) was used to asses interrater reliability. Results: The study population comprised 40 subjects, 27 females en 13 males (median age 59 years, aged 26- 83). The mean measurement of force distribution on the implant supported crown in MIC was 6,9 % (± 6,5) of the total bite force exerted. On the most posterior implant supported crowns the mean measurement of force distribution in MIC was higher (10,4 % (±6,7)). In 20% of the subjects the implant supported crown received much higher force than other teeth during closure. The bilateral left-to-right side force distribution in MIC was 47,26 % to 52,74 % with a mean bilateral force discrepancy of 19,5 % (±13,3). No premature contacts were found on the implant supported crowns. The mean occlusion time was 0,15 sec (±0,09). No infraocclusion on the implant supported crown was found in 23% of the subjects. A statistically significant relation was found between a quantifiable time-delay on the implant supported crown and the corresponding relative force in MIC (r(df)= -0.56, p< 0.01). Working-side interferences on the implant supported crown were found in 30% of the subjects. The ICC values of the separately compared force percentages per tooth in MIC varied from 0,86 (95%- BI: 0,72-0,91) tot 0,96 (95%-BI: 0,9-0,98) . Conclusion: This study shows there are multiple deviations from clinical guidelines for ideal implant occlusion when occlusion in patients with posterior implant supported crowns is established using conventional methods. Within the limitations of this study, it can be stated that, using conventional methods, integration of guidelines for implant-specific occlusion is limited. The T-Scan Novus seems an reliable tool for creating an preservational and guidelines-based implant occlusion. Prevention of occlusal overloading on the implant supported crown by establishing an appropriate implant occlusion could reduce biomechanical complications, thus increasing the longevity of the implant supported crown.
| Item Type: | Thesis (UNSPECIFIED) |
|---|---|
| Supervisor name: | Pelt, Dr. A.W.J. van |
| Faculty: | Medical Sciences |
| Date Deposited: | 19 Nov 2021 13:30 |
| Last Modified: | 19 Nov 2021 13:30 |
| URI: | https://umcg.studenttheses.ub.rug.nl/id/eprint/2806 |
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