Alveolar ridge changes 1-year after early implant placement, with or without alveolar ridge preservation at single-implant sites in the aesthetic region: A secondary analysis of radiographic and profilometric outcomes from a randomized controlled trial

Efficacy of collagenated bone substitutes for bone regeneration in two-wall-damaged extraction sockets without barrier membranes

OBJECTIVES

To evaluate ridge dimensional changes following alveolar ridge augmentation in two-wall-damaged extraction sockets without a barrier membrane, using two types of collagenated bone substitutes i. cross-linked (CL-CB) and ii. non-cross-linked (NCL-CB).

MATERIALS AND METHODS

Two-wall defects were created in mandibles of seven beagle dogs and treated in three groups: (i) no grafting (control), (ii) sockets filled with NCL-CB, and (iii) sockets filled with CL-CB. No barrier membrane was used. One animal was sacrificed after 1 week of healing for tissue assessments (n = 1), and the other six were sacrificed after 8 weeks of healing for microcomputed tomography (micro-CT) and histological analyses (n = 6).

RESULTS

Compared to unextracted sites, radiographic analysis revealed that the alveolar ridge dimension decreased to 83.29 ± 24.96% in group NCL-CB, 73.46 ± 16.59% in group CL-CB and 55.41 ± 12.95% in non-grafted sites (intergroup p = 0.062). Histological analysis showed that compared to baseline values the ridge area decreased to 68.75 ± 14.20% in the non-grafted group, 79.88 ± 20.05% in the NCL-CB group and 76.10 ± 21.09% in the CL-CB group with no significant differences between the groups (p > 0.05). Qualitative histological analyses revealed significantly less mineralized tissue in both test groups, amounting to 25.28 ± 10.40% in group NCL-CB, 29.86 ± 12.04% in group CL-CB, and 67.15 ± 14.35% in non-grafted sites (intergroup p < 0.05).

CONCLUSION

The efficacy of alveolar ridge augmentation using either cross-linked or non-cross-linked collagenated bone substitutes alone might be limited in severely damaged sockets such as those with two-wall defects.

CLINICAL RELEVANCE

In situations where sockets are extensively damaged, like those with two-wall defects, relying solely on soft-type bone block substitutes without a barrier membrane may not provide sufficient bone regeneration. This study highlights the importance of considering additional regenerative strategies, such as the use of barrier membranes, to enhance clinical outcomes.

The effects of β-TCP and/or xenogeneic bone substitute on alveolar ridge preservation: a randomized clinical trial

OBJECTIVES

After tooth extraction, the alveolar ridge undergoes significant absorption, and the alveolar ridge preservation (ARP) will alleviate the complexity of implantation operations in specific clinical occasions and then improve the functionality and aesthetics of subsequent restoration. However, the effectiveness of β-tricalcium phosphate (β-TCP) composite materials for ARP needs to be confirmed by more clinical trials and more sufficient evidence. This study was aimed at evaluating the effects of β-TCP coating porous bovine deproteinization bone (β-TCP/PBDB) on ARP when compared with Bio-Oss®.

MATERIALS AND METHODS

After baseline clinical examination, teeth extractions and the ARP were conducted randomly by β-TCP/PBDB or the Bio-Oss®. A collagen sponge was applied over the bone substitutes. After 6 months, clinical examination and cone-beam computerized tomography (CBCT) imaging analysis were conducted to evaluate the changes in alveolar bone volume.

RESULTS

In the clinical trial, a total of 123 patients successfully completed the protocol. The surgical socket and the soft tissues healed well. The reduction of alveolar ridge width was 1.27 ± 1.32 mm, 0.89 ± 1.31 mm, and 0.63 ± 1.37 mm at three levels (1 mm, 3 mm, 5 mm) below the crest of alveolar ridge respectively using β-TCP/PBDB, while those were 1.12 ± 1.65 mm, 0.55 ± 1.41 mm, 0.56 ± 1.32 mm respectively in the Bio-Oss® group. The reduction of alveolar ridge height was 0.75 ± 1.96 mm in buccal and 0.95 ± 1.96 mm in lingual using β-TCP/PBDB while those were 1.01 ± 2.44 mm and 0.99 ± 2.13 mm respectively in the Bio-Oss® group. There is no significant difference in the width and height changes of the alveolar ridge compared to Bio-Oss® (p > 0.05).

CONCLUSIONS

This prospective, randomized, controlled clinical trial provided evidence that β-TCP/PBDB is a safe material and the effectiveness of β-TCP/PBDB in maintaining the volume and contour of the alveolar ridge is comparable to that of the Bio-Oss® material.

CLINICAL RELEVANCE

The β-TCP/PBDB can be used as one option of bone substitute material for ARP.

In vivo experimental study comparing alveolar ridge preservation versus guided bone regeneration after unassisted socket healing at intact and damaged sites in narrow alveolar ridges

BACKGROUND

To compare bone regeneration and dimensional alteration of alveolar ridge at intact and damaged extraction sockets after alveolar ridge preservation (ARP) and implant placement versus unassisted socket healing followed by guided bone regeneration (GBR) with simultaneous implant placement.

METHODS

In 6 beagle dogs, 3 types of extraction sockets in the mandible were created: (1) intact sockets, (2) 1-wall defect sockets and (3) 2-wall defect sockets. The sockets were allocated to undergo either (1) ARP and implant placement 8 weeks later (ARP group) or (2) GBR with simultaneous implant placement after 8 weeks of unassisted socket healing (GBR group). After an additional healing period of 8 weeks, bone regeneration and dimensional changes were evaluated radiographically and histologically.

RESULTS

GBR showed superior bone formation and greater bone gains compared to ARP, regardless of the initial extraction-socket configuration. Although ARP maintained the preexisting alveolar ridge dimensions, peri-implant bone defects were still detected at 8 weeks of follow-up. Histomorphometric analyses confirmed that GBR increased dimensions of the alveolar ridge compared to baseline, and the augmentation and bone regeneration were greater with GBR than with ARP.

CONCLUSION

Early implant placement with ARP can mitigate alveolar ridge changes in the narrow alveolar ridge. However, early implant placement with simultaneous GBR creates the conditions for enhanced bone regeneration around the implant and greater ridge augmentation compared to ARP, irrespective of the extraction-socket configuration.

Deproteinized Bovine Bone Mineral With Collagen for Anterior Maxillary Ridge Augmentation: A Retrospective Cohort Study

OBJECTIVES

This study aimed to assess the effects of deproteinized bovine bone mineral with collagen (DBBMC) combined with deproteinized bovine bone mineral (DBBM) on facial alveolar bone augmentation in the anterior maxillary region.

MATERIALS AND METHODS

Patients receiving dental implant placement with simultaneous lateral bone augmentation using DBBM (control group) or DBBMC combined with DBBM (test group) were included in the study. The radiographic assessment of facial alveolar bone, such as facial horizontal bone thickness (FHBT), facial vertical bone level (FVBL), and square of facial bone (SFB), was taken by cone beam computed tomography (CBCT). Generalized estimated equation (GEE) was performed to identify influencing factors associated with the contraction in square of facial bone (SFBC).

RESULTS

A total of 164 implants from 164 patients were included in this study. After 6 months post-surgery, the SFBC and the alterations of FHBT and FVBL in the test group were significantly higher than those in the control group (p < 0.05). After 1-2 years after restorations, the SFBC and the alterations of FHBT and FVBL in the test group were significantly lower than those in the control group (p < 0.05). Spearman correlation analysis demonstrated a positive correlation between the alterations of FVBL and FHBT at the implant platform level in the test group (rs = 0.322, p = 0.001; rs = 0.349, p = 0.002). Implant timing of early loading (p = 0.014) and the implant site of the central incisor (p = 0.040) were significantly associated with the SFBC.

CONCLUSIONS

The applications of DBBMC combined with DBBM achieved better facial alveolar bone augmentation in the anterior maxillary region, especially in early implant placement.

3D surface defect map for assessing buccolingual profile of single tooth gaps following alveolar ridge preservation

AIM

A new, non-invasive approach suggests using single intraoral optical scanning to analyze the ridge profile of single-tooth gaps following alveolar ridge preservation in the absence of a baseline scan. This method involves creating a three-dimensional (3D) surface map to identify and assess contour changes and ridge profiles based on the adjacent teeth.

MATERIALS AND METHODS

The present study was designed as a cross-sectional pilot analysis on a convenience sample of patients undergoing alveolar ridge preservation. Intraoral optical scans were taken on 23 patients, capturing data from 30 edentulous sites. The digital models were then imported into an image analysis software for a 3D surface defect map analysis performed by one examiner. This analysis characterized the buccolingual profile of the single tooth gap relative to the adjacent teeth. 10 linear divergence points, spaced 0.5 mm apart in a corona-apical direction, were identified at the midfacial aspect of the sites. Based on these points the sites were plotted and grouped in three different buccolingual profiles (linear, concave, and convex). Clinical parameters including Keratinized mucosa Width (KMW), and soft tissue phenotype with Colorvue biotype probes were also recorded.

RESULTS

Three different buccolingual patterns (linear, convex, and concave) were identified. Seven sites exhibited a linear profile, 10 sites displayed a concave shape, and 13 showed a convex profile. The linear profile had surface discrepancies similar to the neighboring teeth. In contrast, the convex profile revealed mid-buccal discrepancy localized only at the crestal aspect, while the concave had an extended divergence ranging from 1 to 5 mm below the soft tissue margin. Univariate and multiple logistic regression analyses did not reveal any statistically significant variables influencing profilometric analysis; however, when combining phenotype and KMW, thick phenotypes demonstrated a higher proportion of concavity (OR = 4.83) compared to thin ones, suggesting a significant trend. With every 1 mm of increase in KMW, the probability of showing a concavity decreased (p = 0.057).

CONCLUSION

A 3D surface defect map represents a useful tool for objectively quantifying ridge defects and profiles by assessing profilometric and surface differences compared to adjacent dentition using a single intraoral scan. This method also indicates that KMW may play a critical role in preventing concavity defects. The 3D defect map can guide decision-making during soft tissue augmentation procedures by emphasizing the specific location of the defect and providing more detailed insights into its localization. These parameters can enable the tailoring of flap management and soft tissue grafting strategies to address the patient's individual needs.

Alveolar ridge preservation in posterior maxillary teeth for reduction in the potential need for sinus floor elevation procedures: A pilot study

OBJECTIVES

To investigate the effects of alveolar ridge preservation (ARP) on ridge height, sinus pneumatization and the potential need for lateral sinus augmentation following extraction in the posterior maxilla.

MATERIALS AND METHODS

This randomized controlled pilot study included 28 patients requiring extraction in the posterior maxilla with bone height between 6 and 8 mm. The sites were randomly allocated to either unassisted socket healing (Control), ARP with deproteinized bovine bone mineral (DBBM) (Test 1), or collagen-stabilized DBBM (Test 2) groups. Pre- and post-operative CTs at 4 months were taken to determine changes in ridge heights, sinus volume, and the need for sinus floor elevation (SFE) procedures for cases where the residual mid-ridge height was < 5 mm. Site-level analyses for changes in vertical ridge dimensions and sinus volume pre- and post-extraction/ARP were conducted using paired t-tests. Differences in mean changes in vertical ridge dimensions and sinus volume between the groups were determined using one-way ANOVA.

RESULTS

Significantly greater mean mid-ridge height reduction occurred in the control group (-2.7 ± 0.9 mm) compared to Test 1 (0.9 ± 3.7 mm) and Test 2 (1.0 ± 2.8 mm) groups (p < .05). No significant changes in mean mid-ridge height were found in either test groups. Volumetric analysis showed a significantly greater increase in sinus volume in the control group (0.7 ± 0.7 cm3) compared to Test 1 (n = 3, -0.7 ± 0.8 cm3) group (p = .03). 89% of patients in the control group would require lateral window SFE  compared to Test 1 (42.8%) and Test 2 (40%) groups.

CONCLUSION

ARP was effective in attenuating height changes in the middle of the ridge and may reduce sinus pneumatization following extraction in the posterior maxilla. This could potentially decrease the need for more invasive sinus augmentation procedures.

Early implant placement versus ridge preservation and delayed implant placement: Analysis of profilometric, clinician- and patient-reported outcomes from a two-centre RCT

OBJECTIVES

To compare early implant placement (EP) to alveolar ridge preservation and delayed implant placement (ARP/DP) in terms of contour changes, along with clinician- and patient-reported outcome measures (PROMs) until the delivery of the implant-supported restoration.

MATERIALS AND METHODS

Patients with a failing single tooth in the maxilla or mandible were recruited in two centres. After tooth extraction, patients were randomly assigned (1:1) to either EP or ARP/DP. At abutment connection and crown delivery, the buccal contour changes at 3 mm below the mucosal margin (primary outcome) along with clinician- (ease of treatment) and patient-reported outcomes were assessed using numeric rating scales and OHIP-14.

RESULTS

A total of 46 patients were analysed. The mean buccal contour at abutment connection decreased by -1.2 ± 0.6 mm in group EP and -1.6 ± 0.8 mm in group ARP/DP (estimated mean difference; 0.45 [95%CI, -0.02; 0.94]; p = .061) with no significant differences between the groups. ARP/DP was consistently easier than EP across all stages of the surgery (estimated mean difference; 2.0 [95%CI, 1.3; 2.7] p < .001): during flap elevation (EP: 4.8 vs. ARP/DP: 1.6), implant placement (EP: 5.7 vs. ARP/DP: 2.2) and wound closure (EP: 3.4 vs. ARP/DP: 1.6). Both interventions improved quality of life but patients who underwent ARP/DP were significantly more satisfied at the time of crown delivery (ARP/DP: 9.6 vs. EP: 9.1, p = .02).

CONCLUSIONS

EP and ARP/DP show no significant differences in buccal contour changes, aesthetics and patient-reported outcomes. However, ARP/DP is an easier procedure at all stages of the surgery compared to EP and could therefore be the preferred therapy for less experienced clinicians.

Alveolar ridge preservation versus early implant placement in single non-molar sites: A systematic review and meta-analysis

OBJECTIVES

The aim of this systematic review and meta-analyses was to evaluate the outcomes of alveolar ridge preservation (ARP) following extraction of non-molar teeth in comparison to early implant placement (EIP) in terms of clinical and radiographic changes, need for additional augmentation at the time of implant placement, patient-reported outcomes, and implant failure rate.

METHODS

Electronic databases were searched to identify randomized and non-randomized studies that compared ARP to EIP. The risk of bias was assessed using the Cochrane Collaboration's Risk of Bias tool. Data were analyzed using a statistical software program.

RESULTS

A total of 106 studies were identified, of which five studies with 198 non-molar extraction sockets in 198 participants were included. Overall meta-analysis showed significant differences in changes in midfacial mucosal margin (mean difference (MD) -0.09; 95% confidence interval (CI) -0.17 to -0.01; p = .03) and ridge width (MD -1.70; 95% CI -3.19 to -0.20; p = .03) in favor of ARP. The use of ARP was also associated with less need for additional augmentation at implant placement, but the difference was not statistically significant.

CONCLUSIONS

Within the limitation of this review, ARP following extraction of non-molar teeth has short-term positive effects on soft tissue contour, mucosal margin and thickness, and alveolar ridge width and height. It can also simplify future implant treatment by minimizing the need for additional augmentation.

Immediate loading on two adjacent single dental implants with definitive nonsplinted restorations: A proof of concept in the posterior zone

OBJECTIVES

To evaluate clinical, clinician- and patient-reported outcomes (PROs) of two adjacent single posterior implants immediately loaded with definitive single crowns up to 1 year. Ten patients in need of two adjacent posterior single implants were included. All implants were placed applying a fully digital workflow. Definitive screw-retained single zirconia crowns were delivered within 72 h after implant placement. Clinical parameters, patient- and clinician-reported outcomes were assessed up to 1 year of follow-up.

CLINICAL CONSIDERATIONS

Clinical outcomes remained stable, with no implant failures or technical and biological complications throughout the observation period. Patient satisfaction was very high at baseline (crown delivery) and remained consistently high at 6 and 12 months of follow-up. Crown insertion 3 days after implant placement was rated as an easy procedure by clinicians.

CONCLUSIONS

Two adjacent single implants with immediate definitive restorations (<72 h) in the posterior region appear to be a viable and easy treatment option to shorten the overall treatment time and potentially enhancing patient satisfaction. However, randomized controlled trials are needed to confirm the advantages of this treatment protocol over a delayed loading approach.

CLINICAL SIGNIFICANCE

In selected cases, immediate implant loading with definitive restorations in the posterior region appears a valuable and straightforward option to shorten the overall treatment time.