Correlation between Buccal Bone Thickness at Implant Placement in Healed Sites and Buccal Soft Tissue Maturation Pattern: A Prospective Three-Year Study

Risk factors for gingival invagination: A retrospective study

AIM

This study aimed to identify the risk factors for gingival invagination during orthodontic treatment after premolar extraction.

MATERIALS AND METHODS

The medical records of 135 patients who had undergone interdental space closure after premolar extraction were collected, and cone beam computed tomography was performed to determine the presence of gingival invagination. The risk factors were examined using mixed-effects models and generalized propensity score weighting (GPSW) to develop a predictive model.

RESULTS

Univariate analysis revealed that the extraction site, buccal bone thickness 4 mm apical to the cemento-enamel junction (MB1), mid-root buccal bone thickness (MB2) and vertical skeletal relationships were related to gingival invagination (p < .05). Furthermore, a subsequent multivariable mixed-effects model analysis indicated a significantly increased risk of gingival invagination at MB1 < 1 mm (p < .001; odds ratio [ORMB1≤0.5mm] = 29.304; 95% confidence interval [CI]: 8.986-93.807; OR0.5

CONCLUSIONS

The risk of gingival invagination is higher in patients with MB1 < 1 mm and in normodivergent or hyperdivergent patients.

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Key Words

• gingiva
• orthodontics
• periodontal diseases
• risk factors
• tooth extraction

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MESH Headings

• Humans
• Female
• Retrospective Studies
• Male
• Risk Factors
• Cone-Beam Computed Tomography
• Bicuspid/diagnostic imaging
• Adult
• Gingival Diseases/etiology
• Adolescent
• Tooth Extraction/adverse effects
• Young Adult

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Grants

• 2022Z02 Applied Basic Research Program, Affiliated Stomatological Hospital of Southwest Medical University
• 2023ZYD0112 Centralized Guided Local Science and Technology Development Project

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Affiliation(s)

M Han Department of Orthodontics, The Affiliated Stomatological Hospital, Southwest Medical University, Luzhou, China
S H Li Department of Orthodontics, The Affiliated Stomatological Hospital, Southwest Medical University, Luzhou, China
Y Yao Department of Orthodontics, The Affiliated Stomatological Hospital, Southwest Medical University, Luzhou, China
Yijiao Zhao The Center of Digital Dentistry, Faculty of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing, China
L P You Department of Orthodontics, The Affiliated Stomatological Hospital, Southwest Medical University, Luzhou, China
Q Zheng Department of Orthodontics, The Affiliated Stomatological Hospital, Southwest Medical University, Luzhou, China
X M Xu Department of Orthodontics, The Affiliated Stomatological Hospital, Southwest Medical University, Luzhou, China

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Efficacy of the Sausage Technique in Rebuilding the Crestal Buccal Bone Thickness: A Retrospective Analysis

The goal was to evaluate the efficacy of the sausage technique in reconstructing the crestal buccal bone thickness, focusing on the distribution shape of the regenerated volume. Ten implants were placed in five patients with Cawood-Howell class IV defects. A cone beam computed tomography (CBCT) was executed at T0 (before surgery). Guided bone regeneration (GBR) with the sausage technique utilized a resorbable collagen membrane, made of a 50% autologous bone and a 50% anorganic bovine bone matrix (ABBM) mixture. After 6 months, a CBCT (T1) was performed before implant placement. Using CBCT software, a plane parallel to the implant axis intersected perpendicular planes every 1.5 mm from the crest level. T0 and T1 CBCT sections were analyzed, yielding 140 measurements. Statistical analysis via SPSS revealed a significant increase in thickness (average 2.82 ± 1.79 mm). Maximum gains occurred at 4.5 mm from the coronal crest line (3.8 ± 1.51 mm). The GBR sausage technique was effective with minimal post-operative complications, yielding the biggest gain at the mid-ridge sagittal area. Within the analysis limitations, it can be assumed that the sausage technique is effective for horizontal GBR in the maxilla, but a lesser volume might be achieved at the crestal level because it seems to follow a bowed regeneration shape.

Microbiological Analysis of Plaque and Its Composition in Three Patient Groups under Different Orthodontic Treatments

BACKGROUND

This article analyzes differences in microbiological parameters and periodontal health conditions among three patient groups: those undergoing conventional orthodontic treatment with fixed appliances, patients undergoing orthodontic treatment with clear aligners, and a control group receiving no treatment.

MATERIALS AND METHODS

In this study, 60 patients were enrolled. The microbiological analysis employed a qualitative and semi-quantitative methodology of bacterial morphotype analysis.

RESULTS

The analyses revealed a significant difference in favor of clear oral and periodontal health aligners. This could be attributed to better bacterial biofilm removal and reduced mechanical stress on the periodontal ligament, factors facilitated by the ease of clear aligner removal. Significant differences (p-value < 0.05) were observed for the Full-Mouth Plaque Score, Full-Mouth Bleeding Score, Plaque Index, and periodontal health assessment measurements.

CONCLUSIONS

Although overall hygiene appears to be improved in patients in the aligners group compared to those treated with conventional orthodontic appliances, there are no statistically significant results regarding plaque composition. Microbiological aspects will be further addressed using more specific techniques in the follow-up of this research.

A review on guided bone regeneration using titanium mesh

The gold standard for bone regeneration in atrophic ridge patients is guided bone regeneration (GBR). This makes it possible to get enough bone volume for an appropriate implant-prosthetic rehabilitation. The barrier membranes must meet the primary GBR design requirements, which include adequate integration with the surrounding tissue, spaciousness and clinical manageability. Titanium mesh's superior mechanical qualities and biocompatibility have broadened the indications of GBR technology, enabling it to be used to restore alveolar ridges with more significant bone defects. GBR with titanium mesh is being used in many clinical settings and for a range of clinical procedures. Furthermore, several advancements in digitalization and material modification have resulted from the study of GBR using titanium mesh. Hence, we report a review on the various characteristics of titanium mesh and its current use in clinical settings for bone augmentation.

Periodontal Phenotype Modification of Peri-Implant Soft Tissue Deficiency Using Subepithelial Connective Tissue Grafts and Bone Grafts in the Esthetic Region

Peri-implant soft tissue deficiency (PSTD) is a significant factor impacting aesthetics, particularly in the anterior zone, where labial bone resorption and thin peri-implant phenotypes are common. The occurrence of a gray color around the implant fixture due to PSTD can be aesthetically concerning in the esthetic zone. In cases involving natural teeth, autogenous soft tissue grafts such as subepithelial connective tissue grafts (SCTGs), free gingival grafts (FGGs), and coronally advanced flaps (CAFs) are commonly utilized. However, there are limited reports of using bone grafts in conjunction with these techniques for modifying the gingival phenotype around both teeth and implants. In the presented cases where PSTD resulted in visible gray coloration of the implant fixture in the esthetic zone, mechanical and chemical decontamination of the exposed implant surface was performed using a titanium brush and tetracycline (Tc) HCl. Subsequently, to enhance peri-implant mucosa thickness and mask the titanium color, simultaneous SCTG and bone grafting procedures were conducted. Within the limitations of these case reports, successful esthetic outcomes were achieved and maintained without recurrence for 3-6 years following the simultaneous subepithelial connective tissue graft and bone graft procedures. These findings suggest the potential efficacy of this combined approach in addressing PSTD and enhancing aesthetic results around dental implants, though further studies are needed to validate these outcomes.

Simultaneous Implant and Guided Bone Regeneration Using Bovine-Derived Xenograft and Acellular Dermal Matrix in Aesthetic Zone

INTRODUCTION

Implant placement in the maxillary anterior area requires sufficient quantity and quality of both soft and hard tissue. In cases where soft and hard tissues are insufficient, additional regeneration using biomaterials is recommended. Treatment using bovine-derived xenograft and acellular dermal matrix (ADM) may increase bone volume and soft tissue thickness. Case and management: A 65-year-old woman sought help for discomfort and aesthetic issues with her denture, reporting missing teeth (11, 12, 13, 14, and 21) and bone volume shrinkage due to disuse atrophy. Intraoral examination revealed 1 mm gingival thickness. CBCT showed labio-palatal bone thickness of 6.0 mm, 5.8 mm, and 4.7 mm for teeth 21, 12 and 14, respectively. Implant planning and surgical guide fabrication were carried out before the surgery. Surgery included the placement of implants 3.3 mm in diameter and 12 mm in length, with the use of xenograft and ADM. Three months post-op, improvements in soft and hard tissues were observed, with a final prosthesis being a long-span implant-supported bridge.

CONCLUSIONS

Disuse alveolar atrophy causes soft and hard tissue deficiency. The use of xenograft and ADM show favourable results even on a geriatric patient.

Bone regeneration in implant dentistry: Which are the factors affecting the clinical outcome?

The key factors that are needed for bone regeneration to take place include cells (osteoprogenitor and immune-inflammatory cells), a scaffold (blood clot) that facilitates the deposition of the bone matrix, signaling molecules, blood supply, and mechanical stability. However, even when these principles are met, the overall amount of regenerated bone, its stability over time and the incidence of complications may significantly vary. This manuscript provides a critical review on the main local and systemic factors that may have an impact on bone regeneration, trying to focus, whenever possible, on bone regeneration simultaneous to implant placement to treat bone dehiscence/fenestration defects or for bone contouring. In the future, it is likely that bone tissue engineering will change our approach to bone regeneration in implant dentistry by replacing the current biomaterials with osteoinductive scaffolds combined with cells and mechanical/soluble factors and by employing immunomodulatory materials that can both modulate the immune response and control other bone regeneration processes such as osteogenesis, osteoclastogenesis, or inflammation. However, there are currently important knowledge gaps on the biology of osseous formation and on the factors that can influence it that require further investigation. It is recommended that future studies should combine traditional clinical and radiographic assessments with non-invasive imaging and with patient-reported outcome measures. We also envisage that the integration of multi-omics approaches will help uncover the mechanisms responsible for the variability in regenerative outcomes observed in clinical practice.

Influence of buccal bone wall thickness on the peri-implant hard and soft tissue dimensional changes: A systematic review

BACKGROUND

The significance on the association between the peri-implant bucco-lingual dimension (BLD) at the stage of implant placement and the occurrence of biological and esthetic complications is yet unknown.

MATERIAL AND METHODS

Systematic screening of electronic sources was carried out to identify clinical and preclinical studies reporting on the baseline BLD and/or buccal bone thickness (BBT) values. A secondary objective was to assess the effect of simultaneous grafting at sites with deficient or no buccal bone wall (BBW) at baseline. The primary outcome variables were BBT, BLD, and buccal vertical bone loss (VBL) at re-evaluation. Moreover, radiographic, clinical, and patient-reported outcome measures (PROMs) were evaluated.

RESULTS

Overall, 12 clinical and four preclinical studies met the inclusion criteria. Inconsistencies were found in defining the critical BBT across the clinical and preclinical data evaluated. The clinical evidence demonstrated that during healing, dimensional changes occur in the alveolar bone and in the BBW that may compromise the integrity of the peri-implant bone, leading to VBL and mucosal recession (MR), particularly in scenarios exhibiting a thin BBW. The preclinical evidence validated the fact that implants placed in the presence of a thin BBW, are more prone to exhibit major dimensional changes and VBL. Moreover, the clinical data supported that, in scenarios where dehiscence-type defects occur and are left for spontaneous healing, greater VBL and MR together with the occurrence of biologic complications are expected. Furthermore, the augmentation of dehiscence-type defects is associated with hard and soft tissue stability. PROMs were not reported.

CONCLUSIONS

Dimensional changes occur as result of implant placement in healed ridges that may lead to instability of the peri-implant hard and soft tissues. Sites presenting a thin BBW are more prone to exhibit major changes that may compromise the integrity of the buccal bone and may lead to biologic and esthetic complications.

Correlation between Accuracy in Computer-Guided Implantology and Peri-Implant Tissue Stability: A Prospective Clinical and Radiological Pilot Study

The present pilot study was designed by hypothesizing a possible correlation between lack of accuracy in implant placement and peri-implant hard and soft tissue health. A total of five patients underwent computer-guided implant surgery and full-arch immediate loading between 2013 and 2014. They subsequently underwent postoperative cone-beam computed tomography (CBCT). After a follow-up of 5 years, all patients were recalled for a clinical-radiographic evaluation of peri-implant health status. The mean linear deviation was 0.5 ± 0.2 mm at the implant's head and 0.6 ± 0.2 mm at the implant's apex, while the mean angular deviation of the long axis was 2.8° ± 1.2°. A mean marginal bone loss (MBL) of 1.16 ± 0.94 mm and 2.01 ± 1.76 mm was observed after 1 and 5 years of follow-up, respectively. At 5 years, the mean peri-implant probing depth (PPD) was 4.09 ± 1.44 mm, 66.6% of the evaluated implants showed peri-implant bleeding on probing (BOP), keratinized mucosa (KM) was <2 mm in 48.4% of cases, and mucosal recession (REC) ≥ 1 mm was assessed in 45.4% of the included implants. A negative correlation was observed between bucco-palatal/lingual linear inaccuracy and MBL, PPD, BOP, and KM.

Full-Digital Customized Meshes in Guided Bone Regeneration Procedures: A Scoping Review

Meshes, especially titanium ones, are being widely applied in oral surgery. In guided bone regeneration (GBR) procedures, their use is often paired with membranes, being resorbable or non-resorbable. However, they present some limitations, such as difficulty in the treatment of severe bone defects, alongside frequent mesh exposure. Customized meshes, produced by a full-digital process, have been recently introduced in GBR procedures. Therefore, the focus of the present review is to describe the main findings in recent years of clinical trials regarding patient-specific mesh produced by CAD/CAM and 3D printing workflow, made in titanium or even PEEK, applied to GBR surgeries. The purpose is to analyze their clinical management, advantages, and complications. This scoping review considered randomized clinical trials, observational studies, cohort studies, and case series/case reports studies. Studies that did not meet inclusion criteria were excluded. The preferred reporting items for scoping reviews (PRISMA-ScR) consensus was followed. A total of 15 studies were selected for this review. Based on the studies included, the literature suggests that meshes produced by a digital process are used to restore complex and severe bone defects. Moreover, they give satisfactory aesthetic results and fit the defects, counteracting grid exposure. However, more clinical trials should be conducted to evaluate long-term results, the rate of complications, and new materials for mesh manufacturing.

Cone Beam Computed Tomography (CBCT) Evaluation of Alveolar Bone Thickness and Root Angulation in Anterior Maxilla for Planning Immediate Implant Placement

OBJECTIVE

 This retrospective study aimed to measure the labial, palatal, mesial, and distal bone thickness around maxillary central and lateral incisors and canines and height from crest to apex, using cone beam computed tomography (CBCT) images and compare the results based on gender. The second objective of the study was to measure root angulation on CBCT images and its relation with the labial cortical thicknesses.  Material and Methods: After the Institutional Review Board (IRB) approval, a total of 140 CBCT volumes were included in this study according to the set criteria. On each scan, right-side maxillary central, lateral incisors, and canine were selected for the measurements. All the measurements were done at three levels at the alveolar crest (L1), mid-root (L2), and apical region (L3) for each tooth.  Results: The Student's t-test was performed to compare the result of buccal, palatal, mesial, and distal bone thickness, angulation, and height of all subjects. Buccal alveolar bone thickness was minimum at the mid-root region, and the palatal bone thickness was minimum at the crestal region. The mesial bone thickness was minimum at the mid-root level, and distal bone thickness was minimum at the crest level. The available bone height was maximum at the lateral incisor and equal for the central incisor and canine. The canine was the most angulated tooth.

CONCLUSION

 Cone beam computed tomography is a reliable imaging modality to evaluate pre-surgical immediate implant sites and measure alveolar bone thickness. The canine was the most angulated tooth with more buccal alveolar bone thickness.

Significance of buccal bone wall thickness on the fate of peri-implant hard and soft tissues: A systematic review

BACKGROUND

The significance of the association between the peri-implant buccolingual dimension (BLD) at the stage of implant placement and the occurrence of biological and esthetic complications is yet unknown.

MATERIAL AND METHODS

Systematic screening of electronic sources was carried out to identify clinical and preclinical studies reporting on the baseline BLD and/or buccal bone thickness (BBT) values. A secondary objective was to assess the effect of simultaneous grafting at sites with deficient or no buccal bone wall (BBW) at baseline. The primary outcome variables were BBT, BLD, and vertical bone loss (VBL) at re-evaluation. Moreover, radiographic, clinical- and patient-reported outcome measures (PROMs) were evaluated.

RESULTS

Overall, 12 clinical and four preclinical studies met the inclusion criteria. The clinical evidence demonstrated that during healing, dimensional changes occur in the alveolar bone and in the BBW that may compromise the integrity of bone around a dental implant. The preclinical evidence validated the fact that implants placed in the presence of thin BBW are more prone to exhibit major dimensional changes. Moreover, the clinical and preclinical data supported that in scenarios where dehiscence-type defects are left for spontaneous healing, greater VBL and mucosal recession (MR) together with the occurrence of biologic complications are expected. Furthermore, the augmentation of dehiscence-type defects is associated with hard and soft tissue stability.

CONCLUSIONS

Dimensional changes occur as a result of implant placement in healed ridges that may lead to VBL and MR. Thin BBW (≲2 mm) are prone to exhibit major postchanges that may compromise the integrity of the buccal bone, biologic and esthetic complications.

Immediate implant placement utilizing vestibular socket therapy versus early implant placement with contour augmentation for rehabilitation of compromised extraction sockets in the esthetic zone: A randomized controlled clinical trial

OBJECTIVE

The present randomized controlled trial compares for the first time the vestibular socket therapy (VST) to the contour augmentation technique in the management of compromised fresh extraction sockets in the maxillary esthetic zone, regarding mid-facial soft tissue changes (primary outcome), mesial and distal papillae dimensions, horizontal soft tissue changes and labial bone plate thickness at apical, middle and coronal levels (secondary outcomes) over 1-year.

MATERIALS AND METHODS

Forty participants with single nonrestorable maxillary teeth in the esthetic zone were randomized into two groups; VST (test; n = 20) utilizing vestibular access for guided bone regeneration (GBR) with immediate implant placement, or contour augmentation (control; n = 20) undergoing an initial healing period followed by implant placement with GBR through a conventional access flap.

RESULTS

All implants were successfully osseo-integrated, except for one implant in the test group. VST showed significantly less mid-facial soft tissue changes of -0.53 ± 1.17 mm versus -1.87 ± 0.69 mm in the control group (p < 0.001). Similarly, changes in mesial papilla (test = -0.64 ± 0.95 mm, control = -1.20 ± 0.81 mm), distal papilla (test = -0.56 ± 1.17 mm, control = -1.26 ± 0.63 mm), horizontal soft-tissue (test = -0.82 ± 0.95 mm, control = -1.84 ± 0.88 mm; p < 0.05) were significantly less in VST. Intra-group comparisons demonstrated a significant increase in labial bone thickness, with no differences between groups. Regression analysis revealed a significant correlation between VST as well as increased coronal bone thickness with the reduction in mid-facial soft-tissue changes.

CONCLUSION

The VST showed less soft-tissue changes and could represent an innovative technique for implant placement in the maxillary esthetic zone. Both techniques showed a high implant survival rate and increased bone thickness after 12 months.

Stability of contour augmentation of implant-supported single crowns in the esthetic zone: One-year cone-beam computed tomography results of a comparative, randomized, prospective, two-center clinical study using two different bone grafting techniques in early implant placement

BACKGROUND

Early implant placement with contour augmentation could provide support and volume to the hard and soft tissues. Herein, we aimed to ascertain whether freeze-dried bone allograft (FDBA) shares with deproteinized bovine bone material (DBBM) the results for esthetic outcomes for anterior teeth and stability of peri-implant facial bone thickness and height by conducting guided bone regeneration.

METHODS

Forty-eight patients were randomly assigned into two groups. In the control group, autogenous bone chips was used to cover the exposed implant surface, followed by a layer of DBBM. This graft combination was then covered with two layers of collagen membrane. In the test group, the exposed implant surface was covered with FDBA, combined with the collagen membrane. During this study, the hard tissue dimensional changes were measured at 12-months post-implant loading by using cone-beam computed tomography.

RESULTS

At 12 months postoperatively, all 48 implants were clinically successful. The mean thickness of facial bone walls ranged from 1.6 to 2.45 mm at the three levels of measurement in the control group and ranged from 1.6 to 2.10 mm in the test group. The mean facial vertical bone wall peak (IP-FC) after loading 1 year presented with values of 0.8 mm (range, 0.0 to 1.25 mm) and 0.5 mm (range, 0.1 to 1.1 mm) coronal to the implant platform in control and test implants, respectively. There were no significant differences in facial bone wall thickness and IP-FC between groups.

CONCLUSIONS

This study demonstrated that autogenous bone chips plus DBBM or FDBA showed similar outcome of peri-implant buccal bone stability in early implant placement after 1 year.

Full Digital Model-Free Maxillary Prosthetic Rehabilitation by Means of One-Piece Implants: A Proof of Concept Clinical Report with Three-Years Follow Up

Implant rehabilitation is a daily practice in dentistry, and patients often have heightened expectations regarding both the functional and the aesthetic outcome. Implant–abutment connection (IAC) is involved in the long-term aesthetic quality of the rehabilitation. The use of one-piece implants for fixing dentures may prevent the mechanical and biological implication of the implant–abutment interface, resulting in a better quality of hard and soft tissue maintenance. In this case report, we present a novel one-piece implant in a maxillary rehabilitation with a full model-free digital approach.

Implant failure rate and the prevalence of associated risk factors: a 6-year retrospective observational survey

Introduction: The purpose of this monocentric retrospective observational investigation is to evaluate the implant failure rate observed in an oral surgery department and analyze the risk factors associated with them. Preventative measures will be suggested to reduce the incidence of implant failure. Material and method: All implants removed between 2014 and 2020 were analyzed. The main criterion assessed was the overall failure rate over 6 years of activity;the secondary criteria were the risk factors associated with implant failure. Results: 12 out of 376 implants placed between 2014 and 2019 in 11 patients (mean age: 55.5 ±11.5 years);sex ratio M/F=5/6) were removed, for an overall failure rate of 3.11%. The majority, 83% (10/12) of the lost implants, were in the maxilla, while only 17% (2/12) were placed in the mandible. The main risk factors identified were: a III−IV bone type density (75%, 9/12), pre-implant sinus lift surgery (42%, 5/12) smoking (8.3%, 1/12), surgical site infection (8.3%, 1/12) and rheumatoid arthritis (8.3%, 1/12). Conclusion: The failure rate observed in this oral surgery unit is consistent with the other international studies, confirming the compliance with good clinical practices of the healthcare team. Pre-implant bone surgery is the major risk factor to consider before implant surgery.

Buccal Bone Thickness in Anterior and Posterior Teeth-A Systematic Review

(1) Background: Immediate dental implant placement has been a subject of great interest over the last decade. Here, information regarding the anatomy and bone thickness of the jaw prior to dental implant placement is crucial to increase the surgery's success and the patient's safety. The clinical premises for this approach have been controversially discussed. One of those heavily discussed premises is a buccal bone thickness of at least 1 mm thickness. This meta-analysis aims to systematically review buccal bone thickness (BBT) in healthy patients. Thus, the feasibility of immediate dental implant placement in daily practice can be assessed. (2) Methods: A search in the electronic databases was performed to identify articles reporting on BBT that was measured by computed tomography in adults. (3) Results: We were able to find 45 studies, including 4324 patients with 25,452 analyzed teeth. The analysis showed a BBT at the alveolar crest of 0.76 ± 0.49 mm in the maxillary frontal and of 1.42 ± 0.74 mm in the maxillary posterior region. In the mandible, the average measured values were similar to those in the maxilla (front: 0.95 ± 0.58 mm; posterior: 1.20 ± 0.96 mm). In the maxillary frontal region 74.4% and in the mandibular frontal region 61.2% of the crestal buccal bones showed widths <1 mm. (4) Conclusions: In more than 60% of the cases, the BBT at the alveolar crest is <1 mm in maxillary and mandibular frontal regions. This anatomic data supports careful pre-surgical assessment, planning of a buccal graft, and critical selection of indication for immediate implant placement, especially in the maxillary and mandibular frontal and premolar region.

Efficacy of bone-substitute materials use in immediate dental implant placement: A systematic review and meta-analysis

OBJECTIVE

To assess the efficacy of using a bone substitute material (BSM) in the fixture-socket gap in patients undergoing tooth extraction and immediate implant placement.

MATERIALS AND METHODS

MEDLINE, EMBASE, and CENTRAL databases were searched for randomized controlled trials (RCTs). RCTs were screened for eligibility, and data were extracted by two authors independently. Risk of bias (ROB) was assessed using Cochrane's ROB tool 2.0. Primary outcomes were implant failure, overall complications, and soft-tissue esthetics. Secondary outcomes were vertical buccal bone resorption, vertical interproximal bone resorption, horizontal buccal bone resorption, and mid-buccal mucosal recession. Meta-analysis was performed using random-effects model with generic inverse variance weighing. GRADE was used to grade the certainty of the evidence.

RESULTS

After screening 19 544 potentially eligible references, 20 RCTs were included in this review, with a total of 848 patients (916 sites). Most included RCTs were deemed of some concerns (53%) or at low (38%) risk of bias, except for overall complications (high ROB). Implant failure did not differ significantly RR = 0.92 (confidence intervals [CI] 0.34 to 2.46) between using a BSM compared with not using a BSM (NoBSM). BSM use resulted in less horizontal buccal bone resorption (MD = -0.52 mm [95% CI -0.74 to -0.30]), a higher esthetic score (MD = 1.49 [95% CI 0.46 to 2.53]), but also more complications (RR = 3.50 [95% CI 1.11 to 11.1] compared with NoBSM. Too few trials compared types of BSMs against each other to allow for pooled analyses. The certainty of the evidence was considered moderate for all outcomes except implant failure (low), overall complications (very low), and vertical interproximal bone resorption (very low).

CONCLUSION

BSM use during immediate implant placement reduces horizontal buccal bone resorption and improves the periimplant soft-tissue esthetics. Although BSM use increases the risk of predominantly minor complications.

Behavior of Soft Tissue around Platform-Switched Implants and Non-Platform-Switched Implants: A Comparative Three-Year Clinical Study

To verify the influence of platform-switching (PS) on soft tissue behavior by comparing the soft tissue stability around implants with and without PS, during three years of follow-up. The study included patients treated with fixed dentures supported by implants with an internal connection. The radiographic distance between the first bone-to-implant contact (FBIC) and the implant shoulder was assessed. Additionally, the presence of keratinized facial mucosa and the prosthetic crown height (TH) were monitored for three years from the delivery of the definitive crown. These parameters were measured for two different groups: platform-switched implants in the PS group and non-platform-switched (NPS) implants in the NPS group. Seventy-seven implants were considered in the statistical analysis. After three years, the overall FBIC mean value was 0.31 ± 1.00 mm. However, the mean FBIC was 0.66 ± 0.97 mm for the NPS group and -0.05 ± 0.91 mm for the PS group. Moreover, a mean recession of 0.54 ± 1.39 mm was measured for the NPS group, whereas a mean coronal migration of 0.17 ± 0.95 mm was measured for the PS group. A significant correlation was also found between the presence of PS and ΔTH (p ≤ 0.01) over the three years of follow-up. The absence or presence of platform-switching would appear to affect the tendency of the gingival buccal margin towards recession or creeping. Additionally, implant-abutment platform-switching seems to help prevent peri-implant soft tissue recession over time when compared to implants without PS.

Need for lateral bone augmentation at two narrow-diameter implants: A prospective, controlled, clinical study

OBJECTIVES

To detect the potential influence of implant diameter and anatomic factors on the need for bone augmentation procedures (BAPs) when replacing congenitally missing lateral incisors (MLIs).

MATERIALS AND METHODS

Patients with congenitally missing MLIs with a mesio-distal distance between the canine and the central incisor of 5.9-6.3 mm received a Ø2.9 mm implant while Ø3.3 mm implants were placed when the distance was 6.4-7.1 mm. The following linear measurements were recorded using a calliper: width of the alveolar process (WAP), width of the bony alveolar ridge (WAR) and thickness of the facial bone after implant osteotomy (TFB). Guided bone regeneration was performed in case of fenestration- or dehiscence-type defects or a thin TFB (<1.7 mm).

RESULTS

Fifty Ø2.9 mm and 50 Ø3.3 mm were included in 100 patients. WAP and WAR did not differ between the groups (p > .05). TFB was statistically significant larger in the Ø2.9 group (1.75 ± 0.59 mm) compared to the Ø3.3 group (1.5 ± 0.63 mm) (p = .041). Fenestration-type defects (p = .005) and a thin facial bone wall (p = .045) was observed more frequently in the Ø3.3 compared to the Ø2.9 group. Correspondingly, BAP was indicated more frequently in the Ø3.3 compared to the Ø2.9 group (p = .017). WAP, MD and WAR were statistically significant correlated to the need for BAP (p < .001). As independent variable, only WAR influenced the probability of BAP (p < .001).

CONCLUSION

The use of 2.9 diameter implants was correlated to a reduced frequency of BAP compared to 3.3 mm implants, without reaching a statistically significant difference. Measurement of the WAP provides the clinician useful information to predict BAP.

Autogenous Chin Block Grafts in the Aesthetic Zone: A 20-Year Follow-Up Case Report

The successful use of osseointegrated implants in the treatment of partial or complete edentulism requires a sufficient bone support. Whenever rehabilitation in atrophic edentulous areas is needed, bone augmentation procedures are recommended. The aim is to provide adequate amount of supporting bone to achieve a prosthetically guided implant placement. This in turn leads to functional and aesthetic improvements that can be maintained on the long term. Bone grafting of the atrophic site can be performed either prior to implant placement or at the time of implantation. Irrespective of the timing, bone augmentation by means of autogenous bone grafts is a reliable technique, as confirmed by several studies. On the other hand, long-term evidence on the use of autogenous chin block grafts in preprosthetic implant surgery is still scarce. Thus, the purpose of the present case is to report the 20-year clinical and radiological outcome of autogenous chin block grafts used to augment a bilateral defect due to agenesis of the upper lateral incisors for implant placement purposes.

Clinical and Radiographic Evaluation of Simultaneous Alveolar Ridge Augmentation by Means of Preformed Titanium Meshes at Dehiscence-Type Peri-Implant Defects: A Prospective Pilot Study

Background: bone augmentation by means of manually shaped titanium mesh is an established procedure to regenerate atrophic alveolar ridges and recreate a proper contour of the peri-implant bone anatomy. Conversely, current literature on the use of preformed titanium meshes instead of traditional grids remains lacking. Therefore, the aim of the present prospective study was to evaluate the use of preformed titanium mesh to support bone regeneration simultaneously to implant placement at dehiscence-type defects from clinical, radiological, and patient-related outcomes. Methods: 8 implants showing buccal dehiscence defects were treated with preformed titanium mesh directly fixed to flat abutments screwed to the implant. Intrasurgical clinical measurements and radiographic evaluations by means of cone-beam computed tomography scans were performed to assess the horizontal bone gain after 8 months from the augmentation surgery. Biological and patient-centered outcomes were also evaluated.; Results: clinically, a mean horizontal bone gain of 4.95 ± 0.96 mm, and a mean horizontal thickness of the buccal plate of 3.25 ± 0.46 mm were found. A mean horizontal bone gain of 5.06 ± 0.88 mm associated with a mean horizontal thickness of the buccal plate of 3.45 ± 0.68 mm were observed radiographically. From a macroscopic aspect, the remodeled graft appeared well integrated with the host bone. Well vascularized newly formed bone-like tissue was observed in intimate contact with the implants. Conclusions: preformed titanium mesh may be effective in supporting simultaneous horizontal bone regeneration at dehiscence-type peri-implant defects. Titanium mesh exposure still remain an issue in this type of surgery.