Evaluation of the Related Factors Influencing the Stability of Dental Implants

With the development of oral medicine,dental implants has become a very popular solution to remediate the loss of teeth and dental rehabilitation. For the last few decades, the immediate loading protocol have become more and more popular because the increasing demands of shortened treatment time. Implant stability is considered one of the most important parameters in implant dentistry. It affects the healing and successful osseointegration of implants. For any implant procedure, successful implant integration is a prerequisite criterion, which depends on a series of procedure-related and patient-dependent factors. It also has been considered that preoperative measurement is critical and may give valuable information to predict loading time and survival of the implants.

In this clinical study, the samples were collected from patients with single teeth missing who came from the department of prosthodontics from the School of Stomatology of the Fourth Military Medical University.The prospective cohort study was used to investigate the correlation between different factors and the early stability of the implants. And then, using the correlation between different factors and the early implant stability gives predictable data about implant stability and then evaluate the accuracy and reliability.

Ethical and institutional approval was obtained from the study institution. From May 2015 to May 2017, teeth missing consecutive patients requiring implant treatment consented to participate in this study to investigate the correlation between implant stability and bone density.

Cone beam computed tomography (CBCT) was used for preoperative radiological evaluation of the jawbone for each patient, and then bone density in Houndsfield units scale was assessed by SimPlant Pro 11.04 software. Immediately after the implant placement and 12 weeks later, stability measurements were performed with Osstell™ Mentor.The captured data was represented in a quantitative unit called Implant Stability Quotient (ISQ) on a scale from 1 to 100 and averaged for each implant.

The descriptive statistical methods were used to show the differences in bone density and ISQ values among location, gender, age and implant diameter variables. Mann-whitney test was used for comparison of HU values and ISQ values between different age and gender groups. Kruskal-Wallis test was used for comparison of HU values and ISQ values between different location and implant diameter groups. The changes of ISQ values over time were compared using Wilcoxon signed rank test. The Spearman's rank correlation coefficient was used to investigate the correlation between ISQ values and HU values.

At last, to investigate the possible correlations between implant stability and bone density and to study the feasibility of predicting implant stability by using preoperative CBCT.

Eligibility Criteria:
Inclusion Criteria:

* the patients who had undergone tooth extraction within the previous 3 months

Exclusion Criteria:

* those who required bone augmentation simultaneously with implant insertion, and patients with any systemic disease