The functional loading of implants increases their stability: A retrospective clinical study

Clinical and Radiographic Evaluation of Soft Tissue and Bone Status in Immediate Loaded Implants Placed Following Their Extraction in the Maxillary Anterior Region

INTRODUCTION

In the maxillary anterior region, teeth extraction leads to significant soft and hard tissue changes. Immediate implant placement following extraction aims to reduce bone loss and overall treatment time. However, it may result in adverse soft tissue changes impacting esthetics. This study evaluates the clinical and radiographic outcomes of immediately loaded implants in the maxillary anterior region, focusing on soft tissue preservation and bone status.

MATERIALS AND METHODS

This study, conducted from April 2022 to August 2024 at the Department of Oral and Maxillofacial Surgery, Ragas Dental College and Hospital, included 10 immediately loaded implants in seven patients. Following atraumatic extraction, implants were placed and loaded with functional provisional crowns fabricated using three-dimensional (3D) rapid prototyping models. Parameters such as crestal bone loss, buccal and palatal bone width, and interdental papilla thickness were evaluated preoperatively and postoperatively using radiographs and clinical assessments.

RESULTS

The study found significant crestal bone loss at both mesial and distal sites over time, with the greatest loss observed at the three-month follow-up. Buccal and palatal bone width showed no significant differences preoperatively and postoperatively. Interdental papilla thickness and overall pink esthetic scores also showed no significant differences between preoperative and postoperative evaluations.

CONCLUSION

Immediate implant placement in the maxillary anterior region, using 3D rapid prototyping for custom splint fabrication, demonstrated effective preservation of soft tissue profile and bone architecture. This approach provides functional and esthetic benefits, although careful monitoring of crestal bone loss is necessary.

Correlation between peri-implant bone mineral density and primary implant stability based on artificial intelligence classification

Currently, the classification of bone mineral density (BMD) in many research studies remains rather broad, often neglecting localized changes in BMD. This study aims to explore the correlation between peri-implant BMD and primary implant stability using a new artificial intelligence (AI)-based BMD grading system. 49 patients who received dental implant treatment at the Affiliated Hospital of Stomatology of Fujian Medical University were included. Recorded the implant stability quotient (ISQ) after implantation and the insertion torque value (ITV). A new AI-based BMD grading system was used to obtain the distribution of BMD in implant site, and the bone mineral density coefficients (BMDC) of the coronal, middle, apical, and total of the 1 mm site outside the implant were calculated by model overlap and image overlap technology. Our objective was to investigate the relationship between primary implant stability and BMDC values obtained from the new AI-based BMD grading system. There was a significant positive correlation between BMDC and ISQ value in the coronal, middle, and total of the implant (P < 0.05). However, there was no significant correlation between BMDC and ISQ values in the apical (P > 0.05). Furthermore, BMDC was notably higher at implant sites with greater ITV (P < 0.05). BMDC calculated from the new AI-based BMD grading system could more accurately present the BMD distribution in the intended implant site, thereby providing a dependable benchmark for predicting primary implant stability.

Marginal bone level change during sequential loading periods of partial edentulous rehabilitation using immediately loaded self-tapping implants: a 6.5-year retrospective study

PURPOSE

A large number of studies have suggested the practicability and predictability of immediate implant function, but few studies have reported marginal bone level changes during sequential loading periods. The purpose of this study was to evaluate the marginal bone remodeling of immediately loaded self-tapping implants both at each time point and during each loading period between two time points.

MATERIALS AND METHODS

The patients included in this retrospective study were treated with immediately loaded NobelSpeedy Replace implants between August 2008 and July 2009. Differences in the marginal bone level (MBL) at each time point and the marginal bone level change (ΔMBL) between two time points were analyzed with Bonferroni correction (P < .05).

RESULTS

Overall, 24 patients (mean age, 47.3 ± 12.8 years) with 42 immediately loaded implants and a median follow-up of 6.5 years (IQR, 67.8 months) were included. The cumulative survival rate after 10 - 12 years was 95.2%. Continuous but slow marginal bone loss was observed during long-term follow-up. MBL at both 7.5 years and 11 years was significantly lower than that at loading, 6 months, 2 years and 4 years (P < .05). No bone loss difference was found in any period before 4 years of follow up (P > .05). The loading period of 4 years to 7.5 years showed the largest ΔMBL compared to those of other time periods (P < .05).

CONCLUSION

Slight bone loss occurred continuously, and more radical changes of marginal bone can be observed during the period of 4-7.5 years. Thus, long-term effective follow-up of immediately loaded implants is needed.

Factors Affecting Implant Stability Quotients at Immediately and Conventionally Loaded Implants in the Posterior Maxilla: A Split-Mouth Randomized Controlled Trial

PURPOSE

To assess primary and secondary stability of variable-thread tapered implants in the posterior maxilla and analyze the impact of various factors on implant stability quotients (ISQs).

MATERIALS AND METHODS

Twenty-six subjects received 3-4 adjacent implants in the maxillary premolar-molar sextants to replace bilateral tooth loss. The implants on one side were immediately loaded with a provisional fixed prosthesis regardless of their primary stability. The contralateral control implants were conventionally loaded. Bone quality was subjectively recorded and primary stability was assessed by means of insertion torque values (ITVs) and ISQs in 4 directions. Secondary stability was measured by ISQ at definitive prosthesis delivery (3-3.5 months postoperatively), and 12 months after definitive loading. The impact of measurement direction, loading protocol, time, site-related (bone quality, implant position, crestal buccal bone thickness, apical cortical anchorage), and implant-related (implant dimensions, abutment height) variables on ISQs was assessed.

RESULTS

For logistic reasons, ISQs were obtained for only 18 patients with 60 test and 60 control implants. Most of the implants (82%) at baseline had their lowest ISQ on the buccal aspect. There were no significant differences between ISQs measured in the buccal and palatal directions, or between ISQs in the mesial and distal directions. The mean of buccal and palatal ISQs was significantly lower than the mean of the 2 interproximal measurements at all evaluation periods. ISQs were not significantly different between the 2 loading groups at any time point. All implants showed a time-dependent increase in ISQs. Baseline ISQ correlated weakly with bone quality and ITV. None of the variables had a significant impact on baseline ISQs, except for implants in second molar sites which showed poorer primary stability than first premolars.

CONCLUSION

Measurement direction and time are the most significant parameters affecting ISQs of variable-thread tapered implants in the posterior maxilla.

The Bone Buttress Theory: The Effect of the Mechanical Loading of Bone on the Osseointegration of Dental Implants

Simple Summary

The bone, as a vertebrate support tissue, is capable of adapting its structure and function to the mechanical demands resulting from the loads that are produced during the performance of its activity. This regulatory action also occurs during the healing processes of a fracture. The purpose of this study was to determine to what extent a dynamic load was capable of modulating the bone healing response around a titanium implant. The study was carried out on experimental rabbits, to which dental implants were placed in the tibiae and there were two test groups, one in which they did not undergo exercise during healing period and another that ran daily during this process on a treadmill. The trail results showed an improvement in the osseointegration process of the implant in the group in which it was subjected to load. The importance of these results is that it opens the door to a better understanding of the mechanisms that can modulate bone healing, especially around dental implants, supporting implant loading protocols that are based on efficiency.

Abstract

Objectives: To determine the effect of mechanical loading of bone on the stability and histomorphometric variables of the osseointegration of dental implants using an experimental test in an animal model. Materials and Methods: A total of 4 human implants were placed in both tibiae of 10 New Zealand rabbits (n = 40). A 6-week osseointegration was considered, and the rabbits were randomly assigned to two groups: Group A (Test group) included 5 rabbits that ran on a treadmill for 20 min daily during the osseointegration period; Group B (Controls) included the other 5 that were housed conventionally. The monitored variables were related to the primary and secondary stability of the dental implants (implant stability quotient—ISQ), vertical bone growth, bone to implant contact (BIC), area of regenerated bone and the percentage of immature matrix. Results: The results of the study show a greater vertical bone growth (Group A 1.26 ± 0.48 mm, Group B 0.32 ± 0.47 mm, p < 0.001), higher ISQ values (Group A 11.25 ± 6.10 ISQ, 15.73%; Group B 5.80 ± 5.97 ISQ, 7.99%, p = 0.006) and a higher BIC (Group A 19.37%, Group B 23.60%, p = 0.0058) for implants in the test group, with statistically significant differences. A higher percentage of immature bone matrix was observed for implants in the control group (20.68 ± 9.53) than those in the test group (15.38 ± 8.84) (p = 0.108). A larger area of regenerated bone was also observed for the test implants (Group A 280.50 ± 125.40 mm², Group B 228.00 ± 141.40 mm²), but it was not statistically significant (p = 0.121). Conclusions: The mechanical loading of bone improves the stability and the histomorphometric variables of the osseointegration of dental implants.

Mechano-adaptive Responses of Alveolar Bone to Implant Hyper-loading in a pre-clinical in vivo model

OBJECTIVES

Oral implants transmit biting forces to peri-implant bone. In turn, those forces subject peri-implant bone to mechanical stresses and strains. Here, our objective was to understand how peri-implant bone responded to conditions of normal versus hyper-loading in a mouse model.

MATERIAL AND METHODS

Sixty-six mice were randomly assigned to 2 groups; both groups underwent bilateral maxillary first molar extraction followed by complete healing. Titanium alloy implants were placed in healed sites and positioned below the occlusal plane. After osseointegration, a composite crown was affixed to the implant so masticatory loading would ensue. In controls, the remaining dentition was left intact but in the hyper-loaded (test) group, the remaining molars were extracted. 3D finite element analysis (FEA) calculated peri-implant strains resulting from normal and hyper-loading. Peri-implant tissues were analyzed at multiple time points using micro-computed tomography (µCT) imaging, histology, enzymatic assays of bone remodeling, and vital dye labeling to evaluate bone accrual.

RESULTS

Compared to controls, hyper-loaded implants experienced a 3.6-fold increase in occlusal force, producing higher peri-implant strains. Bone formation and resorption were both significantly elevated around hyper-loaded implants, eventually culminating in a significant increase in peri-implant bone volume/total volume (BV/TV). In our mouse model, masticatory hyper-loading of an osseointegrated implant was associated with increased peri-implant strain, increased peri-implant bone remodeling, and a net gain in bone deposition.

CONCLUSION

Hyper-loading results in bone strain with catabolic and anabolic bone responses, leading to a net gain in bone deposition.

Relationship between Implant Length and Implant Stability of Single-Implant Restorations: A 12-Month Follow-Up Clinical Study

Background and Objectives: Implant stability in vivo is contingent on multiple factors, such as bone structure, instrument positioning and implant surface modifications, implant diameter, and implant length. Resonance-frequency analysis is considered a non-invasive, reliable, predictable, and objective method by which to evaluate implant stability, due to its correlation with bone-to-implant contact. The purpose of this study was to evaluate the effect of implant length on the primary and secondary stability of single-implant crown rehabilitations, as measured by resonance-frequency analysis at different times. Materials and Methods: Implants of 10 and 11.5 mm were placed, and the resonance frequency was measured at the time of surgery (T0), as well as at 3 (T1), 6 (T2), and 12 (T3) months post-surgery. Results: A total of 559 implants were placed in 195 patients. Significant differences were observed when comparing the implant stability quotient (ISQ) values at T1, with values for 10-mm implants being greater than those for 11.5-mm implants (p = 0.035). These differences were also observed when comparing ISQ values for buccal and lingual areas. At T0, T2, and T3, no significant differences in ISQ values were observed. The use of 10-mm implants in the anterior maxilla yielded significantly greater values at T0 (p = 0.018) and T1 (p = 0.031) when compared with 11.5-mm implants. Significant differences in measurements were observed only for buccal areas (p = 0.005; p = 0.018). When comparing the sample lengths and sex, women with 11.5-mm implants showed significantly lower results than those with 10-mm implants (p < 0.001). Conclusions: There is a direct relationship between implants of a smaller length and greater ISQ values, with this relationship being most evident in the maxilla and in women.