Retention Of Implant-supported Restorations Research Articles

Comparison of the Effect of Implant Abutment Surface Modifications on the Retention of Implant-Supported Restorations.

To evaluate and compare the difference in retention between implant-supported restorations with and without surface modification of the implant abutments. A total of 30 patients with singletooth implants were restored with cement-retained (Multilink N, Ivoclar) restorations using titanium base abutments (Variobase, Straumann) and randomly assigned surface modifications. Group 1 used nonmodified abutments, group 2 used sandblasted abutments, and group 3 used sandblasted abutments followed by an application of metal primer. All patients were recalled for a baseline examination 6 months after crown placement. The pull-out strength and intergroup distribution of mean pull-out strength were assessed. To assess differences between the three groups, intergroup statistical comparison of continuous variables was done using one-way ANOVA with Tukey correction for multiple group comparisons. The results of the intergroup mean pull-out strength distribution revealed that the distribution of mean ± SD pull-out strength in group 1, group 2, and group 3 were 220.79 ± 94.23, 488.64 ± 84.12, and 705.46 ± 112.75 Ncm, respectively. Sandblasting followed by the application of metal primer produced the highest retention of porcelain-fused-to-metal (PFM) crowns to titanium base abutments, followed by sandblasting alone, with the least retention being observed with no surface treatment.

Effect of Cement Type and Cementation Technique on the Retention of Implant-Supported Restorations.

This study aimed to assess the effect of cement type and cementation technique on the retention of cement-retained implant-supported restorations. In this in vitro study, 20 solid abutments were screwed onto the fixture analogs and were mounted in acrylic resin molds using a surveyor. Twenty computer-aided design/computer-aided manufacturing (CAD/CAM) metal crowns with an occlusal loop were fabricated, divided into two groups (n = 10), and bonded with temporary dental cement (Temp-Bond™; group 1) or glass ionomer (GC; group 2). Each group was subcategorized based on its cementation method (half-filling or abutment replica technique). The cement was applied to the copings that were placed vertically on the abutment with applying a 5-kg load for 10 min. The samples were then incubated at 37°C for 24 h and subjected to 3000 thermal cycles. The samples underwent axial tensile load within a universal testing machine. Data were analyzed using two-way ANOVA. GC cement yielded significantly higher retention than Temp-Bond™ (P < 0.05). In the GC group, the half-filling subgroup showed significantly higher retention than the abutment replica subgroup (P < 0.05). The mean retention value in the Temp-Bond™ group revealed no significant difference between the two subgroups (P > 0.05). GC yielded higher retention than Temp-Bond™ while using the half-filling cementation technique (P = 0.00). However, this difference was not significant between GC and Temp-Bond™ with the abutment replica technique (P = 0.960). Within the limitations of this study, the results showed that permanent cementation with half-filling technique yielded significantly higher retention in implant restorations.

Retentive Strength of Implant-Supported Base Metal Copings Over Short Metal Abutments Using Different Luting Agents and Surface Treatments

To evaluate the effect of surface treatments on retention of implant-supported restorations over short abutments. One hundred twenty metal copings were made on Straumann solid abutments (3 mm length). The copings were divided into 2 groups: control and air abraded (50 μm Al2O3). The copings were luted using Fleck's, Poly F, Panavia F, and Fuji Plus. In resin cements groups, 2 subgroups were studied base on the application of Alloy Primer (n = 10). After conditioning in saliva and 5000 thermal cycles, retentive strengths of specimens were measured. Data were analyzed by 1-way ANOVA and Tukey honestly significant difference tests (α = 0.05). Panavia F 2.0 combined with Alloy Primer showed the most retentive values. In control and air abraded groups, there was no significant difference between the studied luting agents. Alloy Primer significantly increased the retention of copings luted with Panavia F 2.0. Within the limitations of this study, the retentive strength of metal copings over short implant abutments was not improved by airborne-particle abrasion. However, Alloy primer enhanced the retention of metal copings that were luted using Panavia F 2.0.