Buccal bone plate in immediately placed and restored implant with Bio-Oss® collagen graft: a 1-year follow-up study

A New Concept of Horizontal Bone Augmentation Using Collagen Bovine Bone Blocks Without Membrane at Implant Placement: A Preliminary Study

Purpose

A buccal bone thickness (BBT) of at least 1.8-2 mm is necessary to ensure long-term implant stability, and a bone grafting procedure is commonly needed to restore this BBT. This study aims to prove the effectiveness of a novel bone augmentation technique in which minero-organic bone substitutes are solely used to restore adequate BBT, excluding the need for coverage membranes.

Methods

Fifty partially edentulous patients having a residual bone width ranging between 5 and 6 mm were enrolled in this study. The horizontal buccal defects were grafted simultaneously at implant placement. Minero-organic collagen bovine bone blocks (CBBB) were placed on the outer side of the buccal bone wall, and adapted to the defect morphology through slow compressive movements. The grafted sites were not covered with any type of membrane nor stabilized with fixation pins. Cone-beam computed tomography scans were obtained pre-operatively, immediately post-surgery, and four months later. Scans were superimposed on the ITK-Snap software to measure the amount of bone gain and assess the percentage of CBBB resorption. Measurements were effectuated at four different levels apically to crestal level.

Results

Radiographic findings showed BBT increase and CBBB resorption in all cases, four months post-grafting. A mean horizontal bone gain of 1.39 mm was calculated at a crestal level.

Conclusion

Based on these findings, it appears that this novel and user-friendly bone grafting technique can achieve positive outcomes from both clinical and radiographic perspectives.

Histological and Biological Response to Different Types of Biomaterials: A Narrative Single Research Center Experience over Three Decades

Background: In more than three decades of work of the Retrieval Bank of the Laboratory for Undemineralized Hard Tissue Histology of the University of Chieti-Pescara in Italy, many types of biomaterials were received and evaluated. The present retrospective review aimed to evaluate the histological and biological aspects of the evaluated bone substitute biomaterials. Methods: In the present study, the authors prepared a retrospective analysis after the screening of some databases (PubMed, Scopus, and EMBASE) to find papers published from the Retrieval Bank of the Laboratory for Undermineralized Hard Tissue Histology of the University of Chieti-Pescara analyzing only the papers dealing with bone substitute biomaterials and scaffolds, in the form of granules and block grafts, for bone regeneration procedures. Results: Fifty-two articles were found, including in vitro, in vivo, and clinical studies of different biomaterials. These articles were evaluated and organized in tables for a better understanding. Conclusions: Over three decades of studies have made it possible to assess the quality of many bone substitute biomaterials, helping to improve the physicochemical and biological properties of the biomaterials used in daily clinical practice.

Clinical evaluation of the buccal aspect around immediate implant using dual zone therapeutic concept versus buccal gap fill to bone level: A randomized controlled clinical trial

OBJECTIVE

Soft tissue esthetics for immediate implant is considered challenging when restoring a tooth in an esthetic zone. This study aimed to evaluate the buccal aspect after immediate implant using the dual-zone therapeutic concept compared to grafting the buccal gap to the bone crest.

MATERIALS AND METHODS

Twenty-four patients were randomly assigned into either immediate implant with the dual-zone therapeutic concept (DZ, test group) or with bone grafting till buccal bone crest with immediate temporization (BCG, control group). Pink esthetic score (PES), buccal bone loss (BBL), mid-facial recession (MFR), soft tissue thickness (STT), keratinized tissue width (KTW), post-operative swelling (POS), and patient satisfaction (PS) were evaluated for 1 year.

RESULTS

At 12 months the PES in the test group was 11.36 ± 1.69, and 10.80 ± 1.55 in the control group, with no statistically significant difference (p = 0.45). MFR in the DZ and BCG groups was 0.27 ± 0.34 and 0.45 ± 0.44 after 12 months with no statistical significance difference (p = 0.195). The STT assessment showed a statistically significant increase in both groups, however the intergroup comparison was statistically not significant (p = 0.23). The mean KTW in the DZ and BCG groups was 4.55 ± 1.08 and 4.20 ± 0.82 mm, respectively with no statistical significance (p = 0.42). There was no statistical significant difference in patient satisfaction between the two groups except in question number 10 concerning the post-operative swelling which was higher in the DZ group (p = 0.009).

CONCLUSIONS

Both treatment modalities are considered reliable methods to achieve good soft tissue esthetics. However, both treatment modalities were not effective in preventing facial bone resorption despite the use of bone graft.

Immediate implant placement with or without socket grafting: A systematic review and meta-analysis

OBJECTIVES

To assess the effect of grafting the gap (SG) between the implant surface and alveolar socket on hard and soft tissue changes following single immediate implant placement (IIP).

MATERIALS AND METHODS

Two independent reviewers conducted an electronic literature search in Pubmed, Web of Science, Embase and Cochrane databases as well as a manual search to identify eligible clinical studies up to August 2021. Randomized controlled trials (RCTs) comparing IIP with and without SG were included for a qualitative analysis. Meta-analyses were performed when possible.

RESULTS

Out of 3627 records, 15 RCTs were selected and reported on 577 patients who received 604 single immediate implants (IIP + SG: 298 implants in 292 patients; IIP: 306 implants in 285 patients) with a mean follow-up ranging from 4 to 36 months. Two RCTs showed low risk of bias. Meta-analysis revealed 0.59 mm (95% CI [0.41; 0.78], p < 0.001) or 54% less horizontal buccal bone resorption following IIP + SG when compared to IIP alone. In addition, 0.58 mm (95% CI [0.28; 0.88], p < 0.001) less apical migration of the midfacial soft tissue level was found when immediate implants were installed with SG. A trend towards less distal papillary recession was found (MD 0.60 mm, 95% CI [-0.08; 1.28], p = 0.080) when SG was performed, while mesial papillae appeared not significantly affected by SG. Vertical buccal bone changes were also not significantly affected by SG. Insufficient data were available for meta-analyses on horizontal midfacial soft tissue changes, pink esthetic score, marginal bone level changes, probing depth and bleeding on probing. Based on GRADE guidelines, a moderate recommendation for SG following IIP can be made.

CONCLUSION

SG may contribute to horizontal bone preservation and soft tissue stability at the midfacial aspect of immediate implants. Therefore, SG should be considered as an adjunct to IIP in clinical practice.

A Comparative Study of Two Bone Graft Substitutes–InterOss® Collagen and OCS-B Collagen®

Bone is a complex hierarchical tissue composed of organic and inorganic materials that provide structure, support, and protection to organs. However, there are some critical size defects that are unable to regenerate on their own and therefore require clinical repair. Bone graft substitutes allow repair by providing a temporary resorbable device. Among the common filler materials that aid in regeneration is hydroxyapatite particles of either animal or human origin which is used to fill or reconstruct periodontal and bony defects in the mouth. However, particulate graft substitutes suffer from localized migration away from the implantation site, necessitating the use of a barrier membrane. In this study, we designed InterOss Collagen, combining bovine hydroxyapatite granules with porcine-skin derived collagen to form a bone filler composite. Physiochemical properties of InterOss Collagen and a commercially available product, OsteoConductive Substitute-Bovine(OCS-B) Collagen, referred to as OCS-B Collagen, were examined. We found two bone graft substitutes to be mostly similar, though InterOss Collagen showed comparatively higher surface area and porosity. We conducted an in vivo study in rabbits to evaluate local tissue responses, percent material resorption and bone formation and showed that the two materials exhibited similar degradation profiles, inflammatory and healing responses following implantation. Based on these results, InterOss Collagen is a promising dental bone grafting material for periodontal and maxillofacial surgeries.

Does initial buccal crest thickness affect final buccal crest thickness after flapless immediate implant placement and provisionalization: A prospective cone beam computed tomogram cohort study

BACKGROUND

Flapless immediate implant placement and provisionalization (FIIPP) in the aesthetic zone is still controversial. Especially, an initial buccal crest thickness (BCT) of ≤1 mm is thought to be disruptive for the final buccal crest stability jeopardizing the aesthetic outcome.

PURPOSE

To radiographically assess the BCT and buccal crest height (BCH) after 1 year and to calculate the correlation between initial and final achieved BCT.

MATERIALS AND METHODS

The study was designed as a prospective study on FIIPP. Only patients were included in whom one maxillary incisor was considered as lost. In six centers, 100 consecutive patients received FIIPP. Implants were placed in a maximal palatal position of the socket, thereby creating a buccal space of at least 2 mm, which was subsequently filled with a bovine bone substitute. Files of preoperative (T0), peroperative (T1) and 1-year postoperative (T3) cone beam computed tomogram (CBCT) scans were imported into the Maxillim™ software to analyze the changes in BCT-BCH over time.

RESULTS

Preoperatively, 85% of the cases showed a BCT ≤1 mm, in 25% of the patients also a small buccal defect (≤5 mm) was present. Mean BCT at the level of the implant-shoulder increased from 0.6 mm at baseline to 3.3 mm immediate postoperatively and compacted to 2.4 mm after 1 year. Mean BCH improved from 0.7 to 3.1 mm peroperatively, and resorbed to 1.7 mm after 1 year. The Pearson correlation of 0.38 between initial and final BCT was significant (p = 0.01) and therefore is valued as moderate. If only patients (75%) with an intact alveolus were included in the analysis, still a "moderate correlation" of 0.32 (p = 0.01) was calculated.

CONCLUSIONS

A "moderate correlation" was shown for the hypothesis that "thinner preoperative BCT's deliver thinner BCT's" 1 year after performing FIIPP.

Buccal bone dimensional changes at immediate implant sites in the maxillary esthetic zone within a 4-12-month follow-up period: A systematic review and meta-analysis

OBJECTIVE

To evaluate the changes in buccal bone dimensions (CBD) following immediate implant placement in the maxillary esthetic zone and to identify the factors influencing the degree of buccal bone resorption for different placement and restoration protocols.

MATERIAL AND METHODS

An electronic search was conducted using the EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), and MEDLINE (PubMed) databases, combined with a manual and gray literature search, up to January 2021. Selected clinical studies had to report the changes in horizontal buccal bone dimension in maxillary immediate implantation sites (premolar to premolar) at baseline and at follow-up visits within a year of implantation. A meta-analysis was conducted to calculate the mean value of the changes in horizontal and vertical buccal bone dimensions (CHBD and CVBD) around implants. To further investigate the heterogeneity and identify factors associated with buccal bone loss after immediate implant placement, subgroup analysis and univariate meta-regression were performed.

RESULTS

From a total of 3498 articles, 4 randomized controlled trials and 12 nonrandomized controlled trials were included for analysis. The mean survival rate of 568 implants was 99.6%. The mean CHBD and CVBD values were 0.71 mm (95% confidence interval: [0.56, 0.86]) and 0.58 mm (95% confidence interval: [0.43, 0.72]), respectively. For possible factors that related to bone resorption, including buccal bone thickness, flap design, bone grafting, horizontal defect dimension, and restoration protocol, bone grafting was the only variable that significantly influenced CHBD.

CONCLUSIONS

This study demonstrated that immediate implant placement in the esthetic zone does not prevent buccal bone from resorption. Due to data heterogeneity and the small sample size of the studies included in the analysis, further well-conducted, randomized controlled trials with homogeneous samples are required to investigate the correlation of CBD with different variables.

Immediate implant placement combining socket seal abutment and peri-implant socket filling: A prospective case series

OBJECTIVES

The aim of this prospective case series was to assess the implant outcomes as well as hard and soft tissue dimensional changes of immediate implant placement in posterior sites using a custom-made sealing socket abutment (SSA) combined to peri-implant socket filling (PISF).

MATERIAL AND METHODS

Twenty patients were considered for single extraction and immediate implant in upper or lower posterior regions. The remaining peri-implant sockets were filled with Deproteinized Bovine Bone Mineral. Based on intra-oral scans (IOS), custom-made SSAs were placed the same day. Implant survival rate, peri-implant bone changes, peri-implant health and pink esthetic score (PES) were recorded up to 1 year post-implant placement. Moreover, CBCT and IOS were performed to monitor hard and soft tissue dimensional changes.

RESULTS

One implant failed to osseointegrate leading to an implant survival rate of 95% after 1 year. Peri-implant bone changes yielded 0.19 ± 0.31 mm and 84.2% of the implants displayed no or mild bleeding on probing. Horizontal bone remodeling was not significant from baseline to 1 year at any levels. Finally, soft tissue profile was stable in the most cervical area while minor changes occurred during the first 6 months below the gingival margin. The absence of mid-buccal recession (0.07 mm) and good PES were found after 1 year.

CONCLUSION

Despite its limitations, this study showed that immediate implants in the posterior region using the SSA + PISF protocol resulted in promising implant outcomes with limited hard and soft tissue dimensional changes while decreasing the overall treatment time.

Efficacy of different surgical techniques for peri-implant tissue preservation in immediate implant placement: a systematic review and meta-analysis

INTRODUCTION

Preserving peri-implant tissues after immediate implant placement (IIP), especially in aesthetic zones, is a topic of interest.

OBJECTIVES

This systematic review investigated the effects of currently available surgical procedures for preserving peri-implant tissue or ensuring dimensional stability following immediate implant placement.

MATERIALS AND METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement's guidelines were followed, and articles were sought on the PubMed and Cochrane databases with no date restrictions. Only randomised clinical trials that evaluated changes in soft and hard tissues around immediately placed implants were included. Statistical analyses were performed, and the studies´ quality was assessed using the Cochrane Collaboration tool. The agreement between reviewers was assessed based on Cohen's kappa statistics.

RESULTS

Of the 14 studies that met the inclusion criteria, 11 were analysed in the meta-analysis (kappa = 0.814; almost perfect agreement). The use of connective tissue grafts resulted in a significantly greater improvement of the facial gingival level (MD = -0.51; 95% CI: -0.76 to -0.31; p = < .001), and the placement of bone grafts significantly reduced the horizontal resorption of the buccal bone (MD = -0.59; 95% CI: -0.78 to -0.39; p < .001).

CONCLUSION

Connective tissue grafts and bone grafts positively influence tissue preservation around immediately placed implants. Neither the flapless technique nor palatal implant positioning resulted in significant improvements to any of the investigated parameters. Additional longitudinal studies are required.

CLINICAL RELEVANCE

This meta-analysis is useful for discerning the effects of soft tissue augmentation, bone grafting, the flapless technique, and palatal implant positioning on preserving peri-implant tissues after immediate implant placement.

Immediate implant placement and loading in the esthetic area when the buccal socket wall is significantly damaged

OBJECTIVES

Recent clinical recommendations contraindicate immediate implant placement when the socket buccal bone plate is significantly damaged. The connective tissue graft (CTG) is increasingly being used in implant therapy and can replace periodontal defects lacking bone wall in periodontal regenerative surgery. Therefore, CTG could be used to allow immediate implant placement and loading even when the buccal socket wall is damaged, facilitating graft material stability.

CLINICAL CONSIDERATIONS

In the first case, deep bone dehiscence was caused by a vertical root fracture. In the second case, a big bone fenestration was caused by a chronic endodontic periapical lesion. Both cases were treated with immediate implant placement and loading. A buccal CTG was used to compensate for the lack of bone and allow stabilization of the particulate xenograft in the gap between the implant and the damaged buccal socket wall. In both cases, a provisional screw-retained crown was immediately delivered, and the definitive layered zirconia crown was delivered after 3 months. Esthetic results and patient satisfaction monitored for 1 year after loading proved to be encouraging.

CONCLUSIONS

Although further investigations with longer follow-up are required, the approach is likely to yield good results after 1 year of loading.

CLINICAL SIGNIFICANCE

The purpose of this report is to show a surgical approach that seems to be able to overcome the contraindication of the quoted consensus report, which allows for good esthetic results and patient satisfaction even when the buccal bone wall of the extraction socket has been more than 50% compromised, allowing treatment time and cost reduction.

A Narrative Review of the Histological and Histomorphometrical Evaluation of the Peri-Implant Bone in Loaded and Unloaded Dental Implants. A 30-Year Experience (1988-2018)

Background: The aim of the present review was to assess the histological and histomorphometrical data from the paper published by our Laboratory on peri-implant bone in dental implants in different loading conditions. Methods: The papers published in different implant loading conditions, in dental implants retrieved from humans, and in the Hard Tissues Research Center of the University of Chieti-Pescara, Italy, were screened on MEDLINE/PubMed, Embase, Scopus, and other electronic databases until 31 December 2018. Only articles that reported the histological and histomorphometrical values of the Bone-Implant Contact (BIC) were selected. Results: The system selection provided a total of 155 papers. The manuscripts included for the narrative review were 57. These papers provided histological and histomorphometrical data. Conclusions: The bone remodeling around dental implants was found to be a dynamic process; loading changed the microstructure of the peri-implant bone; and implants were found to provide a successful function, over several decades, with different range of degrees of BIC in vivo (varying from a little more than 30% to a little more than 90%). Loaded implants presented a 10%-12% higher BIC values when compared to submerged, unloaded implants, and rougher surfaces had, on average, about a 10% higher BIC than machined surfaces.

[Clinical evaluation of the socket-shield technique for immediate implantation in the maxillary anterior region]

OBJECTIVE

This study aimed to evaluate the clinical effect of the socket-shield technique in the maxillary anterior region at one year after implant placement.

METHODS

Ten patients with maxillary anterior teeth that cannot be reserved were enrolled. Implants were installed following the socket-shield technique and restored six months after the surgery. The thickness of the labial maxillary bone of the implant was compared before and one year after the surgery. At one year follow-up, the reten-tion rate of the implants, Jemt classification, and pink and white aesthetic scores were evaluated. Postoperative complications and patient satisfaction were also analyzed.

RESULTS

One year after installation, the retention rate of the implant was 100%. The thickness of the maxillary bone at the neck, central, and root section of the implant reduced to (0.27±0.21), (0.19±0.20), and (0.28±0.29) mm, respectively, compared with the values immediately after the operation. The thickness of the labial maxillary bone at the three measurement points immediately after and one year after the operation was statistically significant (P<0.05). No significant difference (P>0.05) of the difference thickness between immediate and one year after operation at the three measurement points. The pink esthetic scores of the implant prosthesis was 9.10±0.54, and the white esthetic scores was 9.00±0.63. No complications were observed, and the patients had a high degree of satisfaction.

CONCLUSIONS

The socket-shield technique could provide acceptable treatment results but cannot completely avoid the reconstruction of the labial maxillary bone of the implants. The technique exhibits favo-rable short-term aesthetic result, but its long-term clinical effect and aesthetic problems need to be further studied.

Dimensional changes of buccal bone plate in immediate implants inserted through open flap, open flap and bone grafting and flapless techniques: A cone-beam computed tomography randomized controlled clinical trial

OBJECTIVES

To assess through cone-beam computed tomography (CBCT) buccal alveolar bone alterations after immediate implant placement using the following techniques: open flap and grafting (flap-graft), open flap and no grafting (flap-nograft) and flapless and no grafting (noflap-nograft).

MATERIALS AND METHODS

This was a three-armed parallel group randomized clinical trial with allocation ratio 1:1:1. Patients were eligible in case they needed immediate implant replacing teeth in maxillary premolar area, with sufficient buccal bone support. CBCT was performed immediately after the intervention and 6 months later. The main outcomes were CBCT measurements performed at apical (A-EA), medial (M-EM) and external and internal implant bevel level (B-EB, B-IB) and vertical defect depth (DP). Pain and discomfort, time of surgery and complications were recorded. Differences between groups were estimated through ANOVA tests and post-hoc Scheffe's analysis for pairwise comparisons. Multiple regressions were conducted to estimate influence of gingival biotype and baseline marginal gap dimension.

RESULTS

Forty-five patients were recruited and randomized to treatments with one lost to follow-up. Analysis of variance showed that the effect of treatment technique was not relevant for all horizontal and vertical outcomes. The three techniques exhibited almost complete fill of marginal gap, with a mean residual vertical gap of 0.27 mm and horizontal gap of 0.5 mm. Regression models indicated a positive effect of thick biotype on gap filling and dimensional bone reduction. The noflap-nograft technique resulted less painful.

CONCLUSIONS

The option of noflap-nograft surgery in post-extraction implants allows for minimal surgical intervention with comparable buccal bone changes and gap filling after a follow-up of 6 months in sites with sufficient buccal bone support.

Alterations of the bone dimension following immediate implant placement into extraction socket: systematic review and meta-analysis

AIM

This systematic review was aimed at analysing bone dimensional alterations within the first year following immediate implant placement.

MATERIALS AND METHODS

The electronic search was conducted using MEDLINE (PubMed), Cochrane Central Register of Controlled Trials (CENTRAL) and EMBASE from January 1980 to October 2013. Quality assessment of selected articles was performed using Cochrane Collaboration's tool or Newcastle-Ottawa scale according to the design of each study. A meta-analysis was performed to estimate bone dimensional reduction. Weighted mean differences in bone dimension between baseline and follow-up measurement were calculated. Subgroup analysis and mete-regression were conducted to evaluate the effects of different variables.

RESULTS

A total of 1348 articles were identified following the search process. Six studies were included in the present review. The weighted mean buccal horizontal bone dimensional reduction (BHDr) was 1.07 mm and buccal vertical bone dimensional reduction (BVDr) was 0.78 mm. The weighted mean palatal bone dimensional reduction was 0.62 mm horizontally (PHDr) and 0.50 mm vertically (PVDr). The initial thickness of the buccal alveolar plate (TB) of the socket was the only variable significantly correlated with BHDr and BVDr in meta-regression analysis.

CONCLUSIONS

The bone dimensions of immediate implant sites demonstrated approximately 0.5-1.0 mm reduction in vertical and horizontal aspects 4-12 months following surgery. The results should be interpreted with care because of the data heterogeneity. The correlation of the socket buccal wall thickness, and other variables, with dimensional changes of the bony ridge should be investigated further in controlled clinical trials.

Fixed restorations supported by Morse-taper connection implants: a retrospective clinical study with 10-20 years of follow-up

OBJECTIVES

Rehabilitation with implant-supported fixed prostheses is a predictable modality to restore lost function and esthetics; however, fixed restorations are subject to biological and prosthetic complications, which may represent a problem in the long-term. The aim of this study was to evaluate the long-term survival and complication rates of fixed restorations supported by Morse-taper connection implants.

MATERIALS AND METHODS

Between January 1992 and December 2002, 49 patients (age range 22-70 years), were included in this study. The restorations involved 58 fixed reconstructions (15 single crowns [SCS], 29 partial prostheses, 14 full-arches), supported by 178 Morse-taper connection implants with a follow-up ranging from 10 to 20 years. Outcomes such as implant survival, marginal bone loss, frequency of biological and prosthetic complications as well as "complication-free" survival of restorations were investigated.

RESULTS

The 20-year overall cumulative implant survival was 97.2%. A few biological (3.4%) and prosthetic (10.3%) complications were reported. The "complication-free" survival rate of restorations was 85.5%. No statistically significant differences were observed among patients' gender, age, smoking or parafunctional habits, prosthesis site and type.

CONCLUSIONS

Satisfactory "complication-free" survival rates can be achieved after 20 years for fixed restorations supported by Morse-taper connection implants, with minimal marginal bone loss and complications.