Effect of lateral bone augmentation procedures in correcting peri-implant bone dehiscence and fenestration defects: A systematic review and network meta-analysis

Guided bone regeneration for peri-implant augmentation: A retrospective study comparing two surgical techniques with a mean follow-up of 26 months

OBJECTIVES

To introduce a modified guided bone regeneration (GBR) technique using intact periosteum and deproteinized bovine bone mineral (DBBM) for peri-implant augmentation and compare the clinical outcomes with those of conventional GBR.

MATERIALS AND METHODS

Patients who received peri-implant augmentation in posterior sites between 2015 and 2021 were reviewed in this study. Group A was treated with a modified GBR technique, and Group B was treated with conventional GBR. For group comparison, propensity score matching was performed with a sensitivity analysis. The implant survival rate, dimensional changes in hard tissue, marginal bone loss (MBL), and peri-implant parameters were evaluated.

RESULTS

In total, 114 implants from 98 patients were included. The implant survival rates were 95.74% in Group A and 95.00% in Group B during the follow-up period. At 6 months, the median horizontal thickness was recorded at 0.87 mm (IQ1-IQ3 = 0.00-1.75 mm) in Group A, exhibiting a relatively lower value compared to the corresponding measurement of 0.98 mm (IQ1-IQ3 = 0.00-1.89 mm) in Group B (p = .937). Vertical height displayed no statistically significant intergroup difference between the two groups (p = .758). The mean follow-up period was 25.83 ± 12.93 months after loading in Group A and 27.47 ± 21.29 months in Group B (p = .761). MBL and peri-implant parameters were comparable between the two groups.

CONCLUSIONS

Within the limitations of this study, the modified GBR technique using intact periosteum and DBBM grafting might be a viable alternative to correct bone defects around implants in molar and premolar sites.

3D-printed bredigite scaffolds with ordered arrangement structures promote bone regeneration by inducing macrophage polarization in onlay grafts

Bone tissue engineering scaffolds may provide a potential strategy for onlay bone grafts for oral implants. For determining the fate of scaffold biomaterials and osteogenesis effects, the host immune response is crucial. In the present study, bredigite (BRT) bioceramic scaffolds with an ordered arrangement structure (BRT-O) and a random morphology (BRT-R) were fabricated. The physicochemical properties of scaffolds were first characterized by scanning electron microscopy, mechanical test and micro-Fourier transform infrared spectroscopy. In addition, their osteogenic and immunomodulatory properties in an onlay grafting model were investigated. In vitro, the BRT-O scaffolds facilitated the macrophage polarization towards a pro-regenerative M2 phenotype, which subsequently facilitated the migration and osteogenic differentiation of bone marrow-derived mesenchymal stem cells. In vivo, an onlay grafting model was successfully established in the cranium of rabbits. In addition, the BRT-O scaffolds grafted on rabbit cranium promoted bone regeneration and CD68 + CD206 + M2 macrophage polarization. In conclusion, the 3D-printed BRT-O scaffold presents as a promising scaffold biomaterial for onlay grafts by regulating the local immune microenvironment.

[Role of collagen membrane in modified guided bone regeneration surgery using buccal punch flap approach: A retrospective and radiographical cohort study]

OBJECTIVE

To investigate whether the placement of absorbable collagen membrane increase the stability of alveolar ridge contour after guided bone regeneration (GBR) using buccal punch flap.

METHODS

From June 2019 to June 2023, patients who underwent GBR using buccal punch flap simultaneously with a single implant placement in posterior region (from first premolar to second molar) were divided into coverage group, in which particular bone graft was covered by collagen membrane and non-coverage group. Cone beam CT (CBCT) was taken before surgery (T0), immediately after surgery (T1), and 3-7 months after surgery (T2), and the thickness of the buccal bone plate at different levels (0, 2, 4, and 6 mm) below the smooth-rough interface of the implant (BBT-0, -2, -4, -6) was mea-sured after superimposition of CBCT models using Mimics software.

RESULTS

A total of 29 patients, including 15 patients in coverage group and 14 patients in non-coverage group, were investigated in this study. At T0, T1, and T2, there was no significant difference in BBT between the two groups (P>0.05). At T1, BBT-0 was (2.50±0.90) mm in the coverage group and (2.97±1.28) mm in the non-coverage group, with corresponding BBT-2 of (3.65±1.08) mm and (3.58±1.26) mm, respectively. At T2, BBT-0 was (1.22±0.55) mm in the coverage group and (1.70±0.97) mm in the non-coverage group, with corresponding BBT-2 of (2.32±0.94) mm and (2.57±1.26) mm, respectively. From T1 to T2, there were no statistically significant differences in the absolute values [(0.47±0.54)-(1.33±0.75) mm] and percentages [(10.04%±24.81%)-(48.43%±18.32%)] of BBT change between the two groups. The thickness of new bone formation in the buccal bone plate from T0 to T2 ranged from (1.27±1.09) mm to (2.75±2.15) mm with no statistical difference between the two groups at all levels.

CONCLUSION

In the short term, the GBR using buccal punch flap with or without collagen membrane coverage can effectively repair the buccal implant bone defect. But collagen membrane coverage showed no additional benefit on alveolar ridge contour stability compared with non-membrane coverage.

Using the intact periosteum for horizontal bone augmentation of peri-implant defects: a retrospective cohort study

The objectives of this study were to observe hard tissue changes in guided bone regeneration (GBR) with intact periosteum and soft block deproteinised bovine bone mineral (DBBM), and evaluate whether the result of horizontal bone augmentation varied by initial peri-implant defect depth. Forty patients with a single missing tooth and contained peri-implant defect were categorised into three groups according to their presurgical defect depth (≤ 2, 2-4, and 4-6 mm). Cone-beam computed tomography (CBCT) images were collected and reconstructed preoperatively, postoperatively, and at six months' follow up. The buccal bone width (BBW -0, -3, -5), alveolar bone width (ABW -0, -3, -5) and volume of augmented area were measured. At the six-month follow up the increase in BBW, ABW at all levels, and in bone volume, was statistically significant (all p < 0.001). No statistical significance in bone dimensions or bone resorption was found among groups (all p > 0.05). Histological analysis detected new bone formation in intimate contact with bone grafts underlying the periosteum. Within the limitations of this study, the insights gained may be of assistance to suggest that comparable and acceptable results of horizontal bone augmentation can be achieved in cases of peri-implant defect depth of ≤6 mm by means of GBR with intact periosteum.