RESUMEN
PURPOSE: This systematic review and meta-analysis aimed to investigate the clinical outcomes of xenogeneic bone blocks (XBB) used for lateral ridge augmentation, specifically focusing on bone gain, graft survival, and implant survival. MATERIALS AND METHODS: Data search was conducted in Pubmed, Embase, and ClinicalTrial.gov for randomized controlled trials (RCTs), and prospective cohort studies up to March 1, 2024. Horizontal bone gain (HBG), horizontal bone resorption (HBR), graft survival rate, and implant survival rate were analyzed. Cochrane Risk of Bias Tool 2 and Newcastle-Ottawa Scale were applied to assess the quality and risks of the included studies. RESULTS: Four RCTs and five prospective cohortstudies, comprised 120 graft sites and 141 implants in total were included for the meta- analysis. Non-comparative analysis resulted in a weighted mean horizontal bone gain (HBG) of 4.38 mm and horizontal bone resorption (HBR) of 0.85 mm. Comparative analysis with data from 4 RCTs that paired xenogeneic bone block (XBB) with autogenous bone block (ABB) exhibited a statistically significant greater HBG in XBB, with a mean difference of 0.72mm (95% CI=0.067 to 1.382, p=0.031, I2=28.2%). The weighted graft survival rate for XBB was 91.3% (95% CI = 76.6% to 97.1%, I2 = 58.0 %), and the weighted implant survival rate was 84.3% (95% CI = 72.6% to 91.6%, I2 = 31.6 %). Histologically, mean percentage of mineralized vital bone in XBB ranged from 11.6% to 29.8%, and the resorption rate ranged from 7.3% to 21%. CONCLUSION: The utilization of xenogeneic bone block for lateral ridge augmentation demonstrates an acceptable survival rate and yields an adequate volume of bone for subsequent implant therapy. Nonetheless, the survival rate of implants placed in ridges augmented with xenogeneic blocks is less favorable when compared to those augmented with autogenous block grafts.
RESUMEN
PURPOSE: The aim of this in vitro study was to assess the effects of using different cements and titanium copings designs on the retention of implant-supported fixed dental prostheses (IFDPs) using a pull-out test. MATERIALS AND METHODS: Fifty zirconia (ZirCAD; Ivoclar Vivadent) and 20 prepolymerized denture acrylic resin (AvaDent) rectangular (36 mm × 12 mm × 8 mm) specimens were milled to mimic the lower left segmental portion of the All-on-Four IFDPs. Cylindrical titanium copings (Variobase; Straumann) (V) were used in 2 prepolymerized denture acrylic resin groups (n = 10) while conical titanium copings (Straumann) (C) were used as a control group for zirconia with 4 groups using cylindrical titanium copings. Before cementation, the outer surfaces of all titanium copings and the intaglio bonding surface of prosthetic specimens were airborne-particle abraded. All specimens were cemented following the manufacturer's recommendations and instructions according to the experimental design. After artificial aging (5000 cycles of 5°C 55°C, dwelling time 20 s; 150 N, 1.5 Hz in a 37°C water bath), all specimens were subjected to retention force testing using a pull-out test using a universal testing machine and a custom fixture with a crosshead speed 5 mm/min. Modes of failure were classified as Type 1, 2, or 3. Retention force values were analyzed by the t-test for the prepolymerized denture acrylic resin specimen groups, and 1-way ANOVA and the Tukey test for the zirconia groups at α = 0.05. RESULTS: Mean and standard deviation retention force values varied from 101.1 ± 67.1 to 509.0 ± 65.2 N for the prepolymerized denture acrylic resin specimen groups. The zirconia groups ranged from 572.8 ± 274.7 to 1416.1 ± 258.0 N. There is no statistically significant difference in retention force values between V and C specimens cementing to zirconia with Panavia SA cement (Kuraray Noritake) (p = 0.587). The retention forces and failure modes were influenced by the cement used (p < 0.05). Modes of failure were predominantly Type 2 (mixed failure) and Type 1 (adhesive fracture from prosthetic materials) except for the quick-set resin group (Type 3, adhesive failure from coping). CONCLUSIONS: When bonding IFDPs onto titanium copings, quick-set resin provided significantly higher retention force for prepolymerized denture acrylic resin prostheses. Conical and cylindrical titanium copings performed similarly when cemented to zirconia with Panavia SA cement under the same protocol. The stability of the bonded interface and retention forces between zirconia prostheses and titanium copings varied from the cement used.