Retrospective Clinical Study of a Freely Removable Implant-Supported Fixed Dental Prosthesis by a Microlocking System

Abstract

This retrospective clinical study was conducted to evaluate the clinical usefulness of a freely removable microlocking implant prosthesis (MLP) that was developed to overcome the problems with conventional implant prostheses. A total of 54 patients (male: 31, female: 23) and 100 implant prostheses were included. Patients were divided into three groups such as 6-12 months, 12-18 months, and 18-24 months according to the used period after implant prosthesis delivery, and the patients in each group were recalled for examinations of survival rate, marginal bone resorption, peri-implant soft tissue indices, and complications. The prosthetic complications were analysed by combining the recorded chart data during the periodic checks including the last call for this study. During a 2-year observation period, all the implants showed a 100% survival rate without clinical mobility and functional problems. There was no significant difference in marginal bone resorption, plaque index, and bleeding index over the observation period after implant prosthesis delivery. Probing depth of the 18-24 months group ( 1.5 ± 0.19 mm ) was significantly lower than that of the 6-12 months group ( p < 0.05 ). The main complication was abutment loosening (4%), followed by implant prosthesis fracture (2%) and food impaction (2%) which were recorded. Within the limits of the present study, the implant prostheses with MLP are considered to be an applicable and predictable treatment method.

Influence of an Implant Fixture including a Freely Removable Micro-Locking Implant Prosthesis on Peri-Implant Tissues and Implant Prostheses: A Prospective Clinical Study

“…Several laboratory studies, case reports, and clinical studies have suggested the possible successful clinical application of the ML system [ 26 , 27 , 28 ]. However, in a 1 year prospective clinical study, the cumulative survival rate of implants in MLF was reported to be 100%, which indicates that changing the implant prosthesis connection method would not significantly affect implant survival [ 29 ].…”

“…Radiographs were taken by using a Portable X-ray unit (Port II, Genoray, Seongnam, Korea) and measurements were obtained by using the PACS software (Digi-X, Hanjin Digi-X Co., Seoul, Korea). The means and standard deviations were calculated after scale correction based on known fixture lengths ( Figure 4 ) [ 29 , 35 ].…”

“…Z 1 − α, Z 1 − β was the quantile value from the normal distribution. Based on the findings of a previous non-inferiority margin, (δ) was set at 1.0, significance level (α) at 5%, power (β) at 80%, and standard deviation (σ) at 1.1 [ 29 ].…”

“…The MLA system is connected to fixtures by using an abutment screw, such as the conventional screw-retained implant prostheses, and this connection method is easily applied to existing implant systems. However, complications such as the screw loosening or screw fractures are possible [ 25 , 26 , 27 , 28 , 29 ].…”

“…In order to exclude screw-related mechanical complications, an implant fixture including an ML system that is similar to a one-piece implant was developed. To date, few clinical studies have been conducted on implant fixtures such as the MLA or MLF systems [ 25 , 26 , 27 , 28 , 29 ] and, in order to establish a scientific basis, long-term clinical trials are required for the one-piece ML system. In the present study, marginal bone loss and complications were evaluated by prospective clinical examination and radiological analysis in patients fitted with a screw-free one-piece MLF or a two-piece MLA system.…”