Κλινικές και ακτινογραφικές παράμετροι επιτυχίας μετά από εφαρμογή οστεοενσωματούμενων οδοντικών εμφυτευμάτων: δεκαετής αναδρομική μελέτη

Abstract

IntroductionThe evolution of dental implantology since the 1980s has established osseointegrated implants as a reliable and standard treatment for tooth loss. However, as the initial enthusiasm for this technology has matured, the focus of the scientific community has shifted toward the long-term biological and technical stability of these restorations. This doctoral dissertation explored the long-term clinical and radiographic outcomes of dental implants (specifically the Biomet 3i system) over a functional loading period of at least 10 years (range 10 to 23 years). There is a paucity of studies examining the long-term survival and success of the 3i implant system, with no studies exceeding a follow-up of 10 years and all featuring small samples of implants and patients. Another motivation for this research was the observation in current literature that many studies utilize "convenience samples"—patients treated in highly controlled university environments—which may not reflect the "real-world" challenges of general dental practice. The primary objective was to evaluate implant survival and success rates in a diverse patient population from a private practice environment, specifically analyzing the impact of high-risk factors: history of periodontitis, smoking habits, and the level of adherence to Supportive Periodontal Therapy (SPT). Furthermore, the study investigated the long-term performance of various implant surfaces, connection types (internal vs. external hex), and prosthetic configurations, including the use of cantilevered extensions. Materials and Methods The study utilized a retrospective design, identifying 534 implants placed in 208 patients between 2001 and 2013. An effort was made to contact all patients, inviting them for a re-evaluation visit. Clinical measurements during the follow-up visit included Probing Depth (PD), Attachment Loss (AL), Bleeding on Probing (BOP), Plaque Index (PI), and Gingival Index (GI). Implant and patient characteristics were also recorded. Radiographs of the implants utilizing the parallel technique were taken. Radiographic analysis focused on Marginal Bone Loss (MBL), measured using the imageJ software and comparing baseline (after implant placement) and re-evaluation measurements. Peri-implant health was assessed as Health, Peri-implant mucositis, Peri-implantitis (PI). The primary outcome variable of the study was MBL and the secondary outcome variable was prevalence of PI. Subjective patient satisfaction was assessed using Patient-Related Outcome Measures (PROMs) through a structured questionnaire.ResultsA total of 107 patients with 260 implants were able to present for a re-evaluation appointment. The mean follow-up time was 14.56±3.19 years. The study recorded an overall implant survival rate exceeding 90% over the ten-plus year period, which is consistent with leading international longitudinal studies. The survival rate of implants in function was 98.4%. Clinical and radiographic parameters: The mean values were as follows: MBL: 1.14±1.48 mm, PD: 4.10±1.31 mm, AL: 4.10±1.31 mm., BOP: 17.44±27.22%, PL: 17.44±27.22%. A significant percentage of implants (37.7%) exhibited minimal bone loss , and 17.3% exhibited bone loss exceeding 2 mm. Minimal bone loss was associated with lack of smoking, lack of history of periodontal disease, good oral hygiene and placement in the lower posterior quadrant. Years of loading did not influence MBL or prevalence of PI. Biological Complications and Risk Factors: Peri-implantitis (PI) was diagnosed in15% of implants and 23.4% of patients. A major finding was the significant correlation between periodontal history and peri-implant health. MBL and peri-implantitis prevalence was markedly higher in patients with a history of periodontitis (1.56 mm. and 28.7%) compared to those who were periodontally healthy (0.87 and 6.2%). Smoking was also identified as a critical risk factor, directly associated with increased MBL (1.01 mm vs. 1.44 mm) and a higher prevalence of PI (27% vs. 10.2%).Compliance to Supportive Periodontal Treatment (SPT) did not show statistical significance in this patient group. When sub-group analysis was performed, compliance to SPT was beneficial to non-smokers and patients without a history of periodontal disease. Other factors that showed statistical significance in MBL and prevalence of PI were the morphology of the implant neck (favoring smooth collar implants), depth of placement (favoring placement at the height of the osseous crest). Non-significant factors included internal vs external hex connection, width of keratinized gingiva, history of guided bone regeneration and screw-retained vs cemented abutment to crown connection. Fixed Partial Dental Prostheses With Cantilever Extensions (FPDPC): Nineteen patients with 21 FPDPC's supported by 47 implants were re-evaluated after a mean loading time of 13.3 years. Implant survival rate was 100% and implant success rate was 91.5%, accounting for 4 implants (8.5%) that presented with peri-implantitis. Three of the FPDPC's had to be replaced due to fracture of the cantilever teeth and one other FPDPC had abutment screw fracture which was corrected, leading to prosthetic survival and success rates of 86% and 81%, respectively. Mean MBL from implant placement to time of re-evaluation was 0.99 mm. Patient Feedback (PROMs): 94% of patients reported high satisfaction with their treatment choice and would recommend the procedure to others. Overall, more than 95% of patients were satisfied with the esthetics and function of their implant restorations. Multiple linear regression: When MBL was considered this analysis highlighted the role of smoking, history of periodontal disease, implant length and width of keratinized gingiva as important factors. For PI, important factors were history of periodontitis and width of keratinized gingiva, with marginal significance exhibited by smoking and previous history of guided bone regeneration. DiscussionThis study compared favorably to other long-term retrospective studies as regards the number of patients and the loss to follow-up that is frequently encountered in this type of research. Primary implant success and long-term implant survival percentages are comparable to other long-term studies and meta-analyses, with percentages exceeding 95%. The same was found for mean MBL. The fact that 37% of all implants did not exhibit MBL over time, which was also reported in another study (Donatti, 2018) confirmed the theorem that marginal bone loss was not a natural and inevitable effect of time in function (Donatti, 2018). Prevalence of PI was also comparable to other long-term studies. History of periodontal disease was confirmed as a risk factor for MBL and PI as previously stated in the literature. Smoking as a risk factor has been ambiguous but in this study was found to be a significant risk factor for both variables. A central point of discussion is the role of Supportive Periodontal Therapy (SPT). While overall statistical differences in MBL between compliant and non-compliant groups were not always dramatic, a deeper analysis of non-smokers and periodontally healthy patients revealed that SPT was important for such patients. The conclusion was that smoking and history of periodontal disease were risk factors required stricter SPT protocols in order to show favorable results. Other findings were quite particular for this study, since not many other studies have presented long-term results with regards to depth of implant placement, external vs internal hex connections or cemented vs screw-retained connection. The effect of keratinized gingiva was not adequately addressed because initial recording of that dimension was not performed after prosthesis delivery. Conclusions and Clinical RecommendationsThe 3i implant system showed good long-term efficacy and success with implant survival reaching 98.4% over a mean follow-up of 14.5 years. Marginal bone loss was 1.14 mm and prevalence of peri-implantitis was 15%. History of periodontal disease and smoking were identified as major risk factors, while compliance to SPT, depth of implant placement and the morphology of the implant neck were also found to be statistically significant risk factors. Years of implant loading, nature of hexagonal connection or method of abutment connection, and width of keratinized gingiva were not found to be significant risk factors. A significant percentage of implants (37%) exhibited minimal MBL, which was most often seen in patients without a history of periodontal disease, non-smokers, with good oral hygiene and in implants placed in the lower posterior quadrants. Future research should focus on long-term prospective studies with various implant systems to further elucidate the effect of various risk factors. SPT protocols should also be addressed for patients with multiple risk factors. Finally patient perception of treatment should also be studied and treatments should be tailored to meet patient needs.

Αντικείμενο τους παρούσας διδακτορικής διατριβής ήταν η μακροχρόνια αναδρομική αξιολόγηση (10-23 έτη) τους κλινικής και ακτινογραφικής επιτυχίας οστεοενσωματούμενων εμφυτευμάτων σε συνθήκες καθημερινού ιατρείου. Η μεθοδολογία περιέλαβε την αναδρομική εξέταση106 ασθενών με 260 εμφυτεύματα (Biomet 3i), αξιολογώντας παραμέτρους τους η οστική απώλεια, και ο επιπολασμός περιοδοντίτιδας το ιστορικό περιοδοντίτιδας, το κάπνισμα και η συμμόρφωση σε πρόγραμμα συντήρησης (ΥΠΘ). Τα αποτελέσματα έδειξαν υψηλά ποσοστά επιβίωσης (>90%), ωστόσο η παρουσία περιεμφυτευματίτιδας ήταν σημαντικά αυξημένη σε ασθενείς με ιστορικό περιοδοντίτιδας (28,7%) έναντι υγιών (6,2%). Το κάπνισμα και η ελλιπής συμμόρφωση στην ΥΠΘ αποτέλεσαν κρίσιμους επιβαρυντικούς παράγοντες για την οστική απώλεια. Συμπερασματικά, τα οδοντικά εμφυτεύματα αποτελούν αξιόπιστη λύση μακροπρόθεσμα, αλλά η επιτυχία τους εξαρτάται άμεσα από τον έλεγχο των παραγόντων κινδύνου και τη συστηματική επαγγελματική συντήρηση. Οι προσθετικές αποκαταστάσεις με πρόβολο επέδειξαν εξαιρετική σταθερότητα, ενώ η ικανοποίηση των ασθενών παρέμεινε σε πολύ υψηλά επίπεδα.