Modified Disk-Up Sinus Reamer for Sinus Floor Elevation and Simultaneous Implant Placement: An Animal Study with Miniature Pigs.

Objective: The disk-up sinus reamer (DSR) is a modified instrument used to elevate the maxillary sinus floor. This study aimed to compare the effects of modified DSR sinus floor elevation (DSFE) with osteotome sinus floor elevation (OSFE), both with simultaneous implant placement. Methods: Twelve miniature pigs were treated with DSFE on one side and OSFE on the other. Implants 9 mm in length were placed in six pigs without grafting, while implants 11 mm in length were placed in the other six pigs with grafting. After submerged healing for 3 months, vertical bone gain (VBG), general and histological observation, and bone contact ratio (BCR) were analyzed. Results: The mean maxillary residual bone height (RBH) when implants were placed was 6.45 ± 0.36 mm. In the no-grafting group, DSFE and OSFE had a similar VBG after 3 months. The grafting group with DSFE recorded a significantly higher VBG (VBG0: 7.83 ± 0.44 mm, VBG1: 7.54 ± 0.40 mm) than the graft group with OSFE (VBG0: 5.45 ± 0.56 mm, VBG1: 4.34 ± 2.15 mm) (p < 0.05). One implant became loose and the sinus mucosa of three pigs appeared metallic in color on the control side (OSFE). Conclusions: The effect of OSFE and DSFE is similar when there is no need for grafting. DSFE seems a better alternative method for sinus floor elevation with grafting when more VBG is needed.

Comparative evaluation of BioHPP and titanium as a framework veneered with composite resin for implant-supported fixed dental prostheses.

STATEMENT OF PROBLEM: High rates of veneering chipping are a common prosthodontic complication of restorations with a titanium framework. A new bio high-performance polymer (BioHPP) based on polyetheretherketone (PEEK) has been introduced for denture superstructures. Clinical reports suggest that BioHPP could be used as an alternative framework material to support complete-arch restorations. However, peer-reviewed information is lacking regarding the performance of BioHPP as a framework material for implant-supported screw-retained fixed dental prostheses (FDPs) veneered with composite resin. PURPOSE: The purpose of this in vitro study was to evaluate and compare the bond strength of modified PEEK (BioHHP) and titanium with a veneering composite resin and compare the marginal fit and fracture resistance of implant-supported screw-retained FDPs fabricated by using computer-aided design and computer-aided manufacturing (CAD-CAM) frameworks veneered with composite resin. MATERIAL AND METHODS: A composite resin was bonded to 2 framework materials (n=20/group): pure titanium (Ti) and BioHPP (Bi). The shear bond strength (SBS) was determined after 24-hour wet storage. Furthermore, 20 3-unit CAD-CAM BioHPP and titanium frameworks were fabricated (n=10/group). The marginal fit between frameworks and abutments was evaluated by scanning electron microscopy by using the single-screw test. After thermocycling and mastication simulation, the fracture resistance of FDPs veneered with the composite resin was examined. The independent sample t test was used to evaluate differences (α=.05). RESULTS: Significantly higher shear bond strengths were obtained in group Bi (31.1 ±3.5 MPa) than in group Ti (20.5 ±1.8 MPa). The mean marginal gap width was 19 ±4 µm in group Bi and 16 ±6 µm in group Ti. Statistical tests showed no significant differences (P>.05). After loading, veneering chipping was observed at a load of 1960 ±233 N in group Ti. Although the BioHPP frameworks fractured at 1518 ±134 N, no chipping occurred. CONCLUSIONS: The bond strength of BioHPP with the composite resin was greater than that of titanium. CAD-CAM BioHPP frameworks exhibit good marginal fit and fracture resistance. BioHPP may be a suitable alternative to metal as a framework to be veneered with composite resin.