Profilometric, volumetric, and esthetic analysis of guided bone regeneration with L-shaped collagenated bone substitute and connective tissue graft in the maxillary esthetic zone: A case series with 1-year observational study

Particulate Versus Cross-Linked Collagenated Bone Substitutes for Guided Bone Regeneration: A Randomized Controlled Trial

AIM

To compare the dimensional outcomes of horizontal augmentation with the retentive-flap technique using particulate and cross-linked collagenated bone substitutes.

MATERIALS AND METHODS

This two-centre, two-arm randomized clinical trial investigated 69 subjects: 34 in the particulate group and 35 in the collagenated group. Patients were randomly assigned to receive single implant placement with simultaneous guided bone regeneration (GBR) using either particulate deproteinized porcine bone material (DPBM) or cross-linked collagenated DPBM. Quantitative evaluations were conducted for horizontal width, augmented area, and augmented volume in both hard and soft tissue dimensions.

RESULTS

Immediately after surgery, the collagenated group exhibited higher hard tissue dimensions in terms of horizontal width and augmented area. After 4 months, the difference between the two groups decreased to a non-significant level, mainly attributable to the high shrinkage rate of the collagenated group (32.32 [20.79] %) compared to the particulate group (19.90 [14.33] %). No significant difference was observed regarding the soft tissue contour analyses between the two groups after 4 months.

CONCLUSIONS

There were no significant differences between cross-linked collagenated and particulated DPBMs regarding the dimensional outcomes of horizontal augmentation with the retentive-flap technique. The high resorption rate of the collagenated bone substitute negates its initial superiority in both radiographic and soft tissue dimensions (no. KCT0005348).

Trends in dentomaxillofacial radiology

Oral and maxillofacial diagnostic imaging is of paramount importance in dental clinical diagnosis, treatment planning, and follow-up procedures. Periapical radiographic examination and numerous panoramic systems are used in routine clinical dental practice. Cone beam CT is widely used and currently the method of choice in oral and maxillofacial implantology, endodontics, maxillofacial surgery, periodontics, degenerative temporomandibular joint disease, orthodontics, airway studies, sleep disorders, and forensic dentistry. Another innovative laboratory research tool that offers three-dimensional (3D) detailed high-resolution images of in vitro teeth and neighboring structures with submicrometric accuracy is microcomputed tomography. Ultra-high radiation doses, long scanning times, and high costs preclude its routine clinical use. In response to the high demand for a technique that could provide real-time images using a cost-effective, rapid, user-friendly, and portable technique without ionizing radiation, some authors proposed ultrasound imaging methods as an alternative to X-ray imaging techniques. Ultrasonography can be used in the dentomaxillofacial region for various diagnostic purposes such as salivary gland and superficial tissue examination. Recently, dedicated dental magnetic resonance imaging with appropriate software, hardware, sequences, and field of view tailored to fit dentomaxillofacial anatomy was introduced. Lately, 3D printing technologies and their application in dentistry has attracted attention. During 3D printing a given material is added in successive layers to create a 3D object. The application of this technology has the potential to decrease operation time and minimize operator bias and the possibility of procedural errors. Another hot topic regarding dentomaxillofacial radiology is artificial intelligence, which is a field related to computer science dedicated to developing systems or machines that can perform tasks traditionally associated with human intelligence. It is obvious that further investigation and research in the field of dentomaxillofacial radiology will make great contributions to diagnostic imaging for various dental specialties.

A Flexible Membrane May Improve Bone Regeneration by Increasing Hydrophilicity and Conformability in Lateral Bone Augmentation

Collagen membranes play a crucial role in guided bone regeneration (GBR) by preventing soft tissue infiltration and maintaining space for bone formation. This study investigated the impact of collagen membrane flexibility on GBR outcomes through in vitro and in vivo analyses. Flexible (0.3 mm in width) and stiff (0.5 mm in width) porcine collagen membranes were compared. In vitro tests assessed hydrophilicity, enzymatic degradation, conformability, space maintenance, and tensile strength. An in vivo study using a canine model evaluated bone regeneration in standardized mandibular defects filled with deproteinized porcine bone mineral and covered with no membrane, flexible membrane, or stiff membrane. Micro-computed tomography and histomorphometric analyses were performed at 8 and 16 weeks. The flexible membrane demonstrated superior hydrophilicity, faster enzymatic degradation, and greater conformability in vitro. In vivo, micro-computed tomography analysis revealed similar alveolar ridge widths across all groups. Histomorphometric analysis at 16 weeks showed significantly larger regenerated areas in the flexible membrane group compared to controls in coronal, middle, and apical regions. Both membrane groups exhibited higher regeneration ratios than controls, with significant differences in the coronal area. The flexible membrane group demonstrated significantly higher new bone formation in all regions compared to controls at 16 weeks. These findings suggest that flexible membrane substantially enhances GBR outcomes by increasing hydrophilicity and conformability. The study highlights the potential clinical benefits of incorporating flexible membranes in GBR procedures for improved bone regeneration outcomes.

Enhancing guided bone regeneration with cross-linked collagen-conjugated xenogeneic bone blocks and membrane fixation: A preclinical in vivo study

OBJECTIVE

To determine whether combining cross-linked (CL) collagen-integrated xenogeneic bone blocks stabilized with the fixation of resorbable collagen membranes (CM) can enhance guided bone regeneration (GBR) in the overaugmented calvarial defect model.

MATERIALS AND METHODS

Four circular defects with a diameter of 8 mm were prepared in the calvarium of 13 rabbits. Defects were randomly assigned to receive one of the following treatments: (i) non-cross-linked (NCL) porcine-derived collagen-embedded bone block covered by a CM without fixation (NCL + unfix group); (ii) NCL bone block covered by CM with fixation using bone-tack (NCL + fix group); (iii) cross-linked (CL) porcine-derived collagen-embedded bone block covered by CM without fixation (CL + unfix group); and (iv) CL bone block covered by CM with fixation using bone-tack fixation (CL + fix group). The efficacy of GBR was assessed through histological and molecular analyses after 2 and 8 weeks.

RESULTS

At 2 weeks, there were no significant differences in histologically measured areas of newly formed bone among the groups. At 8 weeks, however, the CL + fix group exhibited a larger area of new bone (5.08 ± 1.09 mm2, mean ± standard deviation) compared to the NCL + unfix (1.62 ± 0.42 mm2; p < .0083), NCL + fix (3.97 ± 1.39 mm2) and CL + unfix (2.55 ± 1.04 mm2) groups. Additionally, the expression levels of tumour necrosis factor-alpha, fibroblast growth factor-2, vascular endothelial growth factor, osteocalcin and calcitonin receptor were significantly higher in the CL + fix group compared to the other three groups (p < .0083).

CONCLUSION

Cross-linked bone blocks stabilized with collagen membrane fixation can significantly enhance GBR.

Profilometric, esthetic, and patient-reported outcomes of the L-shape technique combined with delayed connective tissue grafting in the maxillary anterior region: A 3-year case series study

OBJECTIVE

To evaluate the profilometric, esthetic, and patient-reported outcomes of peri-implant tissues in the maxillary anterior esthetic zone following guided bone regeneration (GBR) using the L-shape technique combined with delayed connective tissue grafting (CTG).

MATERIALS AND METHODS

Profilometric and pink esthetic score (PES) measurements were performed at the time of implant surgery with GBR (T0) and at the 1- (T1), 2- (T2), and 3-year (T3) follow-up. Patient-reported outcomes were also assessed using the Oral Health Impact Profile-14 (OHIP-14) questionnaire. Statistical analysis over 3 years of follow-up assessed changes at time points (T0, T1, T2, and T3) and time periods (T0-T1, T0-T2, and T0-T3) using the Wilcoxon signed-rank test.

RESULTS

A total of 12 patients (57.5 ± 12.3 years) were included in this study. The mean profilometric change in peri-implant tissues over the 3-year follow-up period was 3.49 ± 1.11 mm, and the buccal contours were not significantly different between the comparison periods. The PES remained stable, while all OHIP-14 domain scores improved significantly.

CONCLUSION

Simultaneous implant placement and GBR using the L-shape technique combined with delayed CTG in the maxillary anterior region provides stable buccal profiles and consistent esthetics and improves patient-reported quality of life over a 3-year period.

CLINICAL SIGNIFICANCE

This study demonstrated that GBR using the L-shape technique combined with delayed CTG in the maxillary anterior region improved the buccal profile, esthetics, and patient-reported quality of life.

Clinical outcomes of narrow- and regular-diameter implants with bone augmentation in the anterior maxilla: a systematic review and meta-analysis

OBJECTIVES

To evaluate the clinical outcomes of narrow-diameter implants (NDIs) and regular-diameter implants (RDIs) with bone augmentation in the anterior maxilla, with implant survival rate (ISR) as the primary outcome. Additionally, secondary outcomes such as peri-implant marginal bone loss (MBL), pocket probing depth (PPD), mechanical complications, and biological complications were also considered.

MATERIALS AND METHODS

A thorough literature search was performed to identify randomized controlled trials and cohort studies comparing outcomes of NDIs and RDIs with bone augmentation in the anterior maxilla published up to February 2024. Only studies with a minimum follow-up period of 12 months were selected for analysis. Meta-analysis was performed if at least two articles with similar characteristics were available.

RESULTS

Of the 288 articles initially considered, 5 were included in the analysis, involving 282 NDIs and 100 RDIs. At the 36-month follow-up, no statistically significant differences in ISR, which ranged 93.8-100% for NDIs and were 100% for RDIs, were observed between the two groups (relative risk, 0.989; 95% confidence interval, 0.839-1.165; p = 0.896). Similarly, MBL and PPD did not differ significantly between the two groups. Soft tissue dehiscence was the most common complication found in RDIs.

CONCLUSION

The results indicate that NDIs yield clinical outcomes similar to those of RDIs with bone augmentation in the anterior maxilla over a 36-month follow-up period.

CLINICAL RELEVANCE

Considering the similar clinical outcomes, the shortened treatment duration and more rapid esthetic improvement associated with NDIs may render them preferrable to RDIs with bone augmentation, particularly in this esthetic zone.

Alveolar ridge preservation of damaged or periodontally compromised extraction sockets with bovine- and porcine-derived block bone substitutes: A retrospective case-control study

PURPOSE

Alveolar ridge preservation (ARP) was introduced to minimize postextraction alveolar bone loss and extraction socket remodeling; however, current knowledge of the ARP procedure for nonintact extraction sockets is still limited and inconclusive. This retrospective study aimed to evaluate the difference between using deproteinized bovine bone mineral with 10% collagen (DBBM-C) and deproteinized porcine bone mineral with 10% collagen (DPBM-C) when performing ARP procedures in damaged or periodontally compromised extraction sockets based on clinical, radiographic, and profilometric outcomes.

METHODS

In total, 108 extraction sockets were grafted with 67 DBBM-C and 41 DPBM-C. Changes in radiographic (horizontal width and vertical height) and profilometric outcomes were measured after the ARP procedure and before the implant surgery. Postoperative discomfort (including the severity and duration of pain and swelling), early wound healing outcomes (including spontaneous bleeding and persistent swelling), implant stability, and treatment modalities for implant placement were also assessed.

RESULTS

Radiographically, the DBBM-C group decreased by -1.70 ± 2.26 mm (-21.50%) and - 1.39 ± 1.85 mm (-30.47%) horizontally and vertically, and the corresponding DPBM-C group decreased by -1.66 ± 1.80 mm (-20.82%) and -1.44 ± 1.97 mm (-27.89%) horizontally and vertically at an average of 5.6 months. There were no serious or adverse complications in any of the cases, and none of the measured parameters differed significantly between the groups.

CONCLUSION

Within the limitations of this study, ARP with DBBM-C and DPBM-C showed similar clinical, radiographic, and profilometric outcomes in nonintact extraction sockets.

Evaluation of the clinical and radiographic effectiveness of treating peri-implant bone defects with a new biphasic calcium phosphate bone graft: a prospective, multicenter randomized controlled trial

PURPOSE

Biphasic calcium phosphate (BCP), a widely used biomaterial for bone regeneration, contains synthetic hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP), the ratio of which can be adjusted to modulate the rate of degradation. The aim of this study was to evaluate the clinical and radiographic benefits of reconstructing peri-implant bone defects with a newly developed BCP consisting of 40% β-TCP and 60% HA compared to demineralized bovine bone mineral (DBBM).

METHODS

This prospective, multicenter, parallel, single-blind randomized controlled trial was conducted at the periodontology departments of 3 different dental hospitals. Changes in clinical (defect width and height) and radiographic (augmented horizontal bone thickness) parameters were measured between implant surgery with guided bone regeneration (GBR) and re-entry surgery. Postoperative discomfort (severity and duration of pain and swelling) and early soft-tissue wound healing (dehiscence and inflammation) were also assessed. Data were compared between the BCP (test) and DBBM (control) groups using the independent t-test and the χ² test.

RESULTS

Of the 53 cases included, 27 were in the test group and 26 were in the control group. After a healing period of 18 weeks, the full and mean resolution of buccal dehiscence defects were 59.3% (n=16) and 71.3% in the test group and 42.3% (n=11) and 57.9% in the control group, respectively. There were no significant differences between the groups in terms of the change in mean horizontal bone augmentation (test group: -0.50±0.66 mm vs. control groups: -0.66±0.83 mm, P=0.133), postoperative discomfort, or early wound healing. No adverse or fatal complications occurred in either group.

CONCLUSION

The GBR procedure with the newly developed BCP showed favorable clinical, radiographic, postoperative discomfort-related, and early wound healing outcomes for peri-implant dehiscence defects that were similar to those for DBBM.

TRIAL REGISTRATION

Clinical Research Information Service Identifier: KCT0006428.