Horizontal Alveolar Ridge Augmentation with Xenogenic Block Grafts Compared with Autogenous Bone Block Grafts for Implant-retained Rehabilitation: a Systematic Review and Meta-Analysis

Factors leading to implant failure: An umbrella review of meta-analyses of observational studies and trials

STATEMENT OF PROBLEM

The evidence concerning factors leading to implant failure remains inconclusive. Existing systematic reviews have reported mixed results for patient-related, surgical, and prosthetic factors contributing to implant failure.

PURPOSE

The purpose of this umbrella review was to summarize the evidence and assess existing biases from meta-analyses of randomized controlled trials (RCTs) and observational (cohort and case-control) studies to establish clinically relevant factors associated with implant failure.

MATERIAL AND METHODS

The study had been registered with the International Prospective Register of Systematic Reviews (PROSPERO) (CRD42025634487). The Scopus, PubMed, the Cochrane Database of Systematic Reviews, and Epistemonikos databases were searched from inception until June 2024, and the effect sizes were recalculated using a random-effects model for each meta-analysis. Between-study heterogeneity, 95% prediction interval, small-study effects, excess significance, and credibility ceilings were evaluated. The credibility of evidence from meta-analyses of cohort and case-control studies was ranked by established criteria as nonsignificant, weak, suggestive, highly suggestive, or convincing.

RESULTS

A total of 2922 publications were identified, 224 full-texts were evaluated, and 25 articles describing 35 associations were included in the study. Among meta-analyses of RCTs (n=9), 6 (67%) statistically significant associations were identified (P<.05). According to the GRADE assessment, turned versus anodized implants, submerged versus nonsubmerged implant healing, and bone augmentation with long implants versus short implants were associated with a higher risk of implant failure (high certainty evidence). Short implants (<10 mm) versus long implants (>10 mm) and immediate versus delayed implant placement were associated with higher risk for implant failure (moderate certainty evidence). Among the meta-analyses of cohort and case-control studies (n=26), 18 (69%) associations were statistically significant (P<.05). None were graded as convincing. Highly suggestive evidence was established for the association between smoking and implant failure. Suggestive evidence emerged for associations including periodontally compromised versus periodontally healthy patients, proton pump inhibitor therapy, Crohn's disease, bone quality type II versus type IV, bone quality type III versus type IV, nonsubmerged immediately loaded versus submerged delayed loaded implants, short implants (<10 mm) versus long implants (>10 mm), selective serotonin re-uptake inhibitor therapy, turned versus anodized implants, and immediately loaded versus conventionally loaded implants. These findings remained robust after sensitivity analyses.

CONCLUSIONS

Observational studies suggest that smoking is associated with an increased incidence of implant failure. Evidence from observational and randomized trials has supported using anodized implants for better outcomes. Several factors were identified as leading to an increased risk of dental implant failure. The remaining factors require additional high-quality studies for better assessment and clinical recommendations.

Cone beam computed tomography based upper airway measurement after orthognathic surgery: a comparative evaluation of different imaging software

Cone-beam computed tomography (CBCT) enhances understanding of the upper airway (UA). This study compared three software products' abilities in visualizing and quantifying specific upper airway changes using CBCT. We conducted a retrospective analysis of pre- and post-operative CBCT images from 29 patients using Dolphin (Do), Romexis 5 (Ro5), and Romexis 6 (Ro6) software, focusing on alterations in oropharyngeal volume and minimum cross-sectional area as key indicators of orthognathic surgery outcomes. ANOVA analysis showed significant differences in volume measurements between Do/Ro5 (p = 0.034) and Do/Ro6 (p = 0.047), but no difference between Ro5 and Ro6 (p = 0.685). No significant differences were found in minimum cross-sectional area parameters. Despite standardized protocols, interpretation discrepancies exist between Do and Ro 5/6, possibly due to program-specific properties. Further studies on threshold value comparability are needed for data standardization. Direct comparisons of clinical data from Do, Ro5, and Ro6 are limited due to methodological disparities. Nonetheless, these programs allow reproducible and quantifiable measurements for clinical assessments of these specific airway changes following orthognathic surgery.

Osteoinductively Functionalized 3D-Printed Scaffold for Vertical Bone Augmentation in Beagle Dogs

OBJECTIVE

To evaluate the efficacy of 3D-printed scaffolds that were osteoinductively functionalized with a bone morphogenetic protein 2 (BMP-2)-incorporated biomimetic calcium phosphate particles (BMP-2-inc. BpNcCaP)/hyaluronic acid (HA) composite gel in vertical bone augmentation in beagle dogs.

MATERIALS AND METHODS

Four Beagle dogs were used in this study. Three months after the extraction of 1st, 2nd, 3rd, and 4th premolars at both sides of the lower jaws of Beagle dogs, one or two critical-size vertical bone defects (4 mm vertical bone defect without buccal and lingual bone) on each side were surgically created. The defects were randomly subjected to the following groups: (1) Control (without bone-defect-filling materials); (2) 3D scaffold; (3) BMP2-inc. BpNcCaP/HA-functionalized 3D scaffold. Six weeks post-surgery, samples were harvested and subjected to micro-CT and histomorphometric analyses.

RESULTS

The struts of the BMP2-inc. BpNcCaP/HA-func. 3D scaffold were covered by a thick layer of cemented irregular particles with an average pore size at 327 ± 27 μm. The BpNcCaP/HA-func. 3D scaffold group bore significantly higher bone volume, bone volume fraction, trabecular number, trabecular thickness, bone mineral density, connectivity density, and bone volumes in three directions (mesiodistal, buccolingual, and apicocoronal) when compared with the groups of Control and 3D scaffold. Moreover, the BMP2-inc. BpNcCaP/HA-func. 3D scaffold group bore significantly lower trabecular separation and exhibited significantly higher bone-to-scaffold contact percentage and newly formed bone area percentage within pores in comparison with 3D scaffold.

CONCLUSIONS

BMP2-inc. BpNcCaP/HA-func. 3D scaffold dramatically enhanced vertical alveolar bone augmentation, which suggests a promising application potential of BMP2-inc. BpNcCaP/HA-func. 3D scaffold in dental clinic.

The Use of Autogenous Teeth Tissues Grafts for Alveolar Bone Reconstruction: a Systematic Review

Objectives

Enough bone around the implant is an important factor in ensuring the stability and longevity of the implant. Therefore, alveolar bone regeneration procedures are often required. A relatively new bone substitute is made from autogenous teeth. There are more and more studies in the scientific literature that perform regenerative alveolar bone procedures using autogenous tissues substitutes made from extracted teeth. The objective of this systematic literature review is to systematize information and present conclusions about the effectiveness of this regenerative material.

Material and Methods

Scientific articles were selected using the PRISMA recommendations. Publications have been carried out since January 1, 2012 to January 1, 2022. The review includes articles in English, clinical studies in humans who underwent bone augmentation prior to or during dental implantation using an autogenous teeth tissues substitute.

Results

A total of 7 publications were included in this systematic literature review. Summarizing the data of the publications, 258 patients participated in the studies, 240 subjects were included in the results for various reasons, and a total of 298 implants were inserted. No statistically significant results were found in the five studies. Two studies comparing autogenous tooth graft with xenogeneic bone graft and autogenous teeth tissues showed statistically significant positive results in autogenous tooth group.

Conclusions

Within the limitations of this study, autogenous tissues graft derived from teeth are an effective material and can be used as an alternative to other bone grafts existing on the market. Further studies with a longer follow-up period are needed to validate these findings.

First Clinical Case Report of a Xenograft-Allograft Combination for Alveolar Ridge Augmentation Using a Bovine Bone Substitute Material with Hyaluronate (Cerabone® Plus) Combined with Allogeneic Bone Granules (Maxgraft®)

BACKGROUND

A patient had lost the first left maxillary incisor in the esthetic zone.

METHODS

The defect in the alveolar ridge was reconstructed for an implant-supported restoration using a new xenogeneic bone substitute containing hyaluronate, which was used in combination with allogeneic bone granules.

RESULTS

After three years of follow-up, the dental implant was stable and showed no signs of infection.

CONCLUSIONS

This is the first case report with a long-term follow-up time of three years of a successful clinical application of a xenograft-allograft combination (cerabone® plus combined with maxgraft®) for alveolar ridge augmentation before dental implantation. Cerabone® plus offers volume stability, provides reliable and efficient structural support of the oral soft tissues in the augmented region (particularly crucial in the aesthetic zone), and preserves the alveolar ridge shape.