Screw "tent-pole" grafting technique for reconstruction of large vertical alveolar ridge defects using human mineralized allograft for implant site preparation

An innovative approach to three-dimensional ridge augmentation in the posterior mandible: A case report

INTRODUCTION AND IMPORTANCE

Surgical intervention is necessary to address significant three-dimensional bone loss in the posterior mandibular alveolar ridge when implants are planned, and primary stability cannot be achieved due to anatomical limitations. The objective of this study is to elucidate the surgical procedures for reconstructing significant bone loss in the posterior mandibular region and to present the outcomes and insights gained from this clinical case.

CASE PRESENTATION

A 42-year-old woman exhibited first lower molar loss, significant movement of the second molar, and severe bone loss at the same site. Vertical and horizontal bone augmentation was performed to enable the restoration of teeth loss by inserting dental implants.

CLINICAL DISCUSSION

Significant bone loss poses a great limitation in replacing missing teeth, particularly in the posterior mandible, given anatomical constraints. Therefore, it is essential to establish an adequate amount of bone to ensure primary stability for the implants.

CONCLUSION

This clinical case demonstrates a restoration technique of severe bone loss in the posterior mandible to enable stable dental implant placement, highlighting the importance of combining vertical and horizontal augmentation to overcome anatomical limitations and ensure primary stability.

Utilization of Tenting Pole Abutments for the Reconstruction of Severely Resorbed Alveolar Bone: Technical Considerations and Case Series Reports

INTRODUCTION

Although various surgical techniques have been utilized in the reconstruction of severely resorbed alveolar bone, its regeneration is still regarded as a major challenge. Most of the surgical techniques used in advanced ridge augmentation have the disadvantages of prolonging the patient's edentulous healing and increasing the need for surgical revisits because simultaneous implant placement is not allowed. This report presents a new and simplified method for advanced ridge augmentation, which utilizes a vertical tenting device.

CASE PRESENTATION

The first case presented the reconstruction of the mandibular posterior region with severely resorbed alveolar bone due to peri-implantitis using tenting pole abutment for ridge augmentation. The second and third cases presented three-dimensional ridge augmentations in severely resorbed ridges due to periodontitis. The last case presented horizontal ridge augmentation using a vertical tenting device. All cases were performed under local anesthesia. Implants were simultaneously placed in the bone defect area. A vertical tensioning device was then connected to the implant platform to minimize the collapse of the bone graft during the bone regeneration period due to the contraction of the soft tissue matrix. A sticky bone graft was transplanted onto the exposed surface of the implant and on top of the vertical tensioning device. After covering with an absorbable barrier membrane, the soft tissues were sutured without tension.

CONCLUSIONS

In all cases, prosthetic restorations were provided to patients after a bone grafting period of 5-6 months, leading to a rapid restoration of masticatory function. Results tracked for up to 6 years revealed observed stable reconstruction of the alveolar bone. The use of a vertical tenting device can prevent the collapse of biomaterials in the augmented ridge during the healing period, leading to predictable outcomes when achieving three-dimensional ridge augmentation.

Improved ridge width with tenting screw bone augmentation using particulate and block grafts: A case report

The objective of this case report is to present the use of tenting screw bone augmentation technique for the rehabilitation of narrow horizontally deficient mandibular ridges and to evaluate the feasibility and outcomes of this approach in achieving sufficient bone volume for successful implant placement and Osseointegration. A 34-year-old woman with no significant medical history presented with bilaterally missing teeth in the lower arch. A comprehensive treatment plan was developed through assessment and Cone Beam Computed Tomography (CBCT) imaging to evaluate the ridge dimensions and plan the treatment accordingly accurately. The tenting screw technique, utilizing autogenous/autologous+allograft materials, was chosen for horizontal ridge augmentation. Bone augmentations were performed simultaneously bilaterally using tenting screws. After a 20-week healing period, CBCT scans revealed favorable bone regeneration with adequate width for successful implant placements. This case report demonstrates the potential of tenting screw bone augmentation in effectively rehabilitating mandibular ridges and achieving optimal dental implant outcomes. Further research is needed to validate these findings and assess the long-term stability and success of this technique.

Tent-pole technique for alveolar ridge width preservation with a compromised buccal plate: a prospective cohort study

Objectives

The aim of this study was to assess the effectiveness of the tent-pole technique for alveolar ridge preservation of compromised alveolar socket following the surgical extraction of incurable single root premolars.

Materials and methods

This study was conducted on 12 patients who presented to the department of oral and maxillofacial surgery and had alveolar ridge preservation using tent-pole technique between August 2021 and February 2022. The alveolar ridge width was analyzed using cone beam computed tomography scans taken preoperative and 6 months postoperative. Statistical analysis was performed to assess the alveolar ridge width at different levels. The alveolar ridge width differences between periods were assessed with paired t-test. The comparison of alveolar ridge width loss according to jaw, sex, and different levels were done with unpaired t-test. The level of significance considered was 5% (α=0.05).

Results

The mean alveolar ridge width before surgery was 10.03 mm. After 6 months, the mean alveolar ridge width was 8.4 mm. The range of alveolar ridge width loss was between 0.6 and 3.22 mm with a mean of 1.63 (16.25%). There was no statistically significant difference in width loss between the maxilla and mandibular whether in males or females. Alveolar bone width loss was the greatest at W1 level (26.8%).

Conclusion

According to the results of this study, the authors conclude that the tent-pole technique could preserve the alveolar bone ridge width without bone graft materials.

Intra-sinus rigid fixation of a resorbable barrier membrane to repair a large perforation of the sinus membrane: a technical note

A resorbable barrier membrane is commonly used for the repair of perforated sinus membranes during sinus lifting surgeries. However, repairing largescale perforations poses challenges for clinicians as the protection and isolation of graft material remain uncertain. With this technique, we aimed to prevent graft material loss and subsequent sinus-related complications using intra-sinus rigid fixation of the resorbable barrier membrane in cases with a large perforation of the sinus membrane.

Radiographic evaluation of the tenting screw technique in horizontal alveolar bone augmentation: A retrospective study

OBJECTIVES

To radiographically analyze the effects of tenting screw technique (TS) and onlay bone grafts (OG) in horizontal bone augmentation.

MATERIALS AND METHODS

Patients receiving horizontal bone augmentation by TS or OG were selected. The clinical outcomes and cone beam computed tomography (CBCT) data were documented pre-grafting, immediately post-grafting, before and after implantation. The survival rates, clinical complications, alveolar bone width, and volumetric bone augmentation were evaluated and statistically analyzed.

RESULTS

A total of 25 patients and 41 implants were involved in this study, with no grafting failures observed in either the TS group (n = 20) or the onlay group (n = 21). Volumetric bone resorption rate in the TS group (21.34%) was significantly lower than that of the OG group (29.38%). In addition, significant horizontal bone gain was achieved in both groups (TS: 6.15 ± 2.12 mm; OG: 4.86 ± 1.40 mm) during the recovery period, with higher gain in the TS group. No apparent statistical difference in terms of volumetric bone gain was observed between the TS (748.53 mm³ , 607.47 mm³ ) and OG group (811.77 mm³ , 508.49 mm³ ) immediately post-grafting or after the recovery period.

CONCLUSION

Both TS and OG achieved satisfactory bone augmentation effects, yet TS resulted in more bone augmentation and better stability than OG, with a reduced use of autogenous bone. Overall, the tenting screw technique can serve as an effective alternative to autogenous bone grafts.

Reconstruction of vertical alveolar ridge deficiencies utilizing a high-density polytetrafluoroethylene membrane /clinical impact of flap dehiscence on treatment outcomes: case series/

Objectives

The aim of this study was to evaluate the effects of membrane exposure during vertical ridge augmentation (VRA) utilizing guided bone regeneration with a dense polytetrafluoroethylene (d-PTFE) membrane and a tent-pole space maintaining approach by registering radiographic volumetric, linear and morphological changes.

Methods

In 8 cases alveolar ridge defects were accessed utilizing a split-thickness flap design. Following flap elevation VRA was performed with tent-pole space maintaining approach utilizing the combination of a non-reinforced d-PTFE membrane and a composite graft (1:1 ratio of autogenous bone chips and bovine derived xenografts). Three-dimensional radiographic evaluation of hard tissue changes was carried out with the sequence of cone-beam computed tomography (CBCT) image segmentation, spatial registration and 3D subtraction analysis.

Results

Class I or class II membrane exposure was observed in four cases. Average hard tissue gain was found to be 0.70 cm3 ± 0.31 cm3 and 0.82 cm3 ± 0.40 cm3 with and without membrane exposure resulting in a 17% difference. Vertical hard tissue gain averaged 4.06 mm ± 0.56 mm and 3.55 mm ± 0.43 mm in case of submerged and open healing, respectively. Difference in this regard was 14% between the two groups. Horizontal ridge width at 9-month follow-up was 5.89 mm ± 0.51 mm and 5.61 mm ± 1.21 mm with and without a membrane exposure respectively, resulting in a 5% difference.

Conclusions

With the help of the currently reported 3D radiographic evaluation method, it can be concluded that exposure of the new-generation d-PTFE membrane had less negative impact on clinical results compared to literature data reporting on expanded polytetrafluoroethylene membranes.

Antifouling poly(PEGMA) grafting modified titanium surface reduces osseointegration through resisting adhesion of bone marrow mesenchymal stem cells

As an alternative strategy to achieve the desired bone augmentation, tenting screw technology (TST) has considerably broadened the indications for implant treatment. Titanium tenting screws are typically used in TST to maintain the space for bone regeneration. However, a high degree of osteogenic integration complicate titanium tenting screw removal and impact the bone healing micro-environment. Previous efforts have been focused on modifying titanium surfaces to enhance osseointegration while ignoring the opposite process. Due to the vital role of bone marrow mesenchymal stem cells (BMSCs) in bone regeneration, it might be feasible to reduce osseointegration around titanium tenting screws by resisting the adhesion of BMSCs. Herein, poly(ethylene glycol)methyl ether methacrylate (poly(PEGMA)) with an optimal length of PEG chain was incorporated with a Ti surface in terms of surface-initiated activators regenerated by electron transfer atom transfer radical polymerization (SI-ARGET ATRP). The cell apoptosis analysis showed that the new surface would not induce the apoptosis of BMSCs. Then, the adhesive and proliferative behaviors of BMSCs on the surface were analyzed which indicated that the poly(PEGMA) surface could inhibit the proliferation of BMSCs through resisting the adhesion process. Furthermore, in vivo experiments revealed the presence of the poly(PEGMA) on the surface resulted in a lower bone formation and osseointegration compared with the Ti group. Collectively, this dense poly(PEGMA) surface of Ti may serve as a promising material for clinical applications in the future. STATEMENT OF SIGNIFICANCE: The significance of this research includes: The poly(ethylene glycol)methyl ether methacrylate (poly(PEGMA)) with an optimal length of PEG chain was grafted onto a Ti surface by surface-initiated activators regenerated by electron transfer atom transfer radical polymerization (SI-ARGET ATRP). The PEGMA surface could reduce the osteogenic integration by preventing the adhesion of cells, resulting in a lower pullout force of the modified implant and thereby desirable and feasible applications in dental surgery.

The Aesthetic Contour Graft - Enhancing peri-implant soft tissue contours and pontic sites with guided bone regeneration

Objective

In this article, we will discuss strategies for enhancing peri‐implant soft tissue contours and pontic sites with hard tissue augmentation.

Clinical consideration

One of the keys to the esthetic illusion of an implant‐supported restoration is to create an ideal emergence profile. A critical part of any emergence profile is based on the height and thickness of the tissue surrounding the restoration and whether there are any defects in this tissue. Even when there is adequate bone in which to place implants, if any irregular ridge anatomy that supports this tissue is not corrected, then an unesthetic appearance of the restoration can result due to the lack of soft tissue with which to develop a proper emergence profile.

Conclusion

Most peri‐implant soft tissue deficiencies represent an underlying bony defect that can be corrected or enhanced through bone augmentation.

Clinical significance

Traditional methods of enhancing soft tissue emergence profiles around implants and pontic sites mostly involve the use of soft tissue augmentation techniques. Although there are few reports of the use of bone augmentation for this purpose, soft tissue contours can be enhanced by augmenting the underlying bone contours and, in many instances, may obviate the need for subsequent soft tissue augmentation.

The effect of 3-D printed polylactic acid scaffold with and without hyaluronic acid on bone regeneration

BACKGROUND

Three- dimensional (3D) technology has been suggested to overcome these limitations in guided bone regeneration (GBR) procedures because 3D-printed scaffolds can be easily molded to patient-specific bone defect site. This study aimed to investigate the effect of 3-D printed polylactic acid (PLA) scaffolds with or without hyaluronic acid (HA) in a rabbit calvaria model.

METHODS

A calvaria defect with a diameter of 15 mm was created in 30 New Zealand white rabbits. The rabbits were randomly allocated into 3 groups including no graft group (control, n = 10) , 3D printed PLA graft group (3D-PLA, n = 10) , and 3D printed PLA with hyaluronic acid graft group (3D-PLA/HA, n = 10) . Five animals in each group were sacrificed at 4 and 12 weeks after surgery. Microcomputed tomography and histologic and histomorphometric analyses were performed.

RESULTS

Over the whole examination period, no significant adverse reactions were observed. There were no statistically significant differences in bone volume (BV) /tissue volume (TV) among the three groups at 4 weeks. However, the highest BV/TV was observed in the 3D-PLA/HA group at 12 weeks. The new bone area for control, 3D-PLA, and 3D-PLA/HA showed no statistical differences at 4 weeks. However, the value was significantly higher in the 3D-PLA and 3D-PLA/HA groups compared to the control group at 12 weeks.

CONCLUSION

The 3D printed PLA scaffolds was biocompatible and integrated well with bone defect margin. They were also provided the proper space for new bone formation. Therefore, 3D printed PLA/HA might be a potential tool to enhance bone augmentation. This article is protected by copyright. All rights reserved.

Exposure management of a titanium-reinforced dense polytetrafluoroethylene mesh used in a vertical ridge augmentation: a case report with 1-year follow-up

INTRODUCTION

A new titanium-reinforced dense polytetrafluoroethylene mesh (TR-dPTFEM) has recently been introduced for vertical ridge augmentation (VRA). Since primary closure is required, the literature lacks information on its behavior in case of premature exposure. To the author's knowledge, this is the first report about TR-dPTFEM complication management.

CASE PRESENTATION

A TR-dPTFEM was used for the VRA in the molar region of the upper right maxilla. The defect was filled with a mix of particulate autogenous bone and porcine xenograft in a 1:1 ratio. A collagen membrane covered the hole pattern of the TR-dPTFEM to prevent soft tissue growth within the grafted material during the first weeks. After a 4-month uneventful healing period, a 4-mm exposure occurred without infection. Patient was prescribed 0.2% chlorhexidine mouth rinse three times a day and manual cleansing with gauze soaked in 3% hydrogen peroxide, and was recalled for weekly follow-up. One month later, the clinical situation was unchanged and the site was re-entered. After TR-dPTFEM removal, the regenerated tissue appeared to be covered with a thin layer of connective tissue. The favorable bone quality made it possible to obtain the primary stability of two implants. At implant uncovering, a gingival graft augmented the keratinized mucosa width. Two screw-retained crowns were delivered 4 months after implant insertion and the 1-year follow-up showed perfectly maintained hard and soft tissues.

CONCLUSION

A late TR-dPTFEM exposure, managed under strict hygiene control, did not affect this VRA. The augmented bone remained stable 1 year after prosthetic loading.

KEY POINTS

Why is this case new information? A novel titanium reinforced PTFE mesh has been recently introduced for vertical ridge augmentation. This case report adds new information to the literature about the management and clinical outcome in a case of exposure. What are the keys to successful management of this case? Weekly check-up of the patient by the clinician Patient's ability to keep the wound clean and disinfected What are the primary limitations to success in this case? Impossibility of being able to check the patient at least once a week Acute infection.

Outcomes of alveolar segmental 'sandwich' osteotomy with interpositional particulate allograft for severe vertical defects in the anterior maxilla and mandible

The purpose of this study was to report the outcomes of interpositional osteotomy with mineralized allograft in the treatment of alveolar vertical defects in preparation for implant placement. Thirteen defects (11 maxillary and two mandibular) were treated with osteotomy segments ranging in length from two to five missing teeth. The segments were positioned 5-7 mm coronally, with the gap space filled with allograft and then fixated with titanium hardware. Vertical bone augmentation was analyzed by superimposing pre- and post-surgical cone beam computed tomography images and stratified based on the length and number of missing teeth in each edentulous segment. The mean vertical bone gain was 3.7 ± 1.6 mm in the area of greatest vertical defect and the mean length of the transport segment was 20.5 ± 8.1 mm. These segments represented two-, three-, four-, or five-tooth edentulous sites; the mean vertical bone gain for these segments was 1.7 ± 0.5 mm, 3.8 ± 1.0 mm, 4.6 ± 0.9 mm, and 6.7 ± 0.0 mm, respectively. Stability of vertical height gain was found to be directly proportional to the span length of the osteotomy segment, with the largest five-tooth segment achieving the greatest gain. Vertical bone gain in two-tooth segments was minimal, indicating a moderate amount of resorption.

"Periimplant Mucositis" Secondary to Infection of Residual Bone Allograft Embedded in the Periimplant Sulcus of a Patient with Diabetes: A Case Report

INTRODUCTION

Currently, inflammation of tissue around implants is diagnosed as either periimplant mucositis or periimplantitis, and the etiology is bacterial biofilm colonization of the implant and its transmucosal component. The purpose of this manuscript is to report a case of "periimplant mucositis" secondary to infection of a residual bone allograft embedded in the periimplant sulcus of a patient with diabetes.

CASE PRESENTATION

A #8 implant was placed and provisionalized in a 46-year-old male patient. During implant placement, facial contour augmentation with an allograft (1000-2000 μm), a collagen membrane, and a connective tissue graft was performed. Healing was uneventful. The crown was removed 9 months after implant placement; a graft particulate was observed in the periimplant sulcus and left undisturbed. The subgingival contour of the crown was adjusted, and the crown was reseated. The patient subsequently developed soreness and foul smell at #8. The crown was removed, and the previously observed graft particulate was more exposed and contaminated. It was removed and the crown was reseated. A month later, symptoms persisted. Palpation produced suppuration. A facial flap was reflected, and residual graft particulates embedded in the facial flap were removed. The site was grafted with a connective tissue graft. Subsequently, symptoms resolved, and the implant was restored.

CONCLUSION(S)

Within the limitation of this case report, it appears residual graft materials can get infected once exposed to the oral cavity and subsequently induce an inflammatory response in the surrounding tissue, especially in a patient with hyperglycemia.

Comparison of Autogenous Block Bone Graft and Screw Tent-Pole Techniques for Vertical Bone Augmentation in the Posterior Mandible: A Split-Mouth Randomized Controlled Study

Aim:

To evaluate the effect on vertical bone augmentation of the screw tent-pole technique using particulate allograft in combination with injectable platelet-rich fibrin, and to compare this with autogenous block bone graft.

Materials and Methods:

This split-mouth randomized controlled study involved patients with bilateral partial edentulism and vertical bone loss in the posterior mandible. In each patient, the control side was treated with autogenous block bone graft harvested from the mandibular ramus and, on the test side, the screw tent-pole technique was employed, using particulate allograft in combination with injectable platelet-rich fibrin. All augmented sites were covered by leukocyte and platelet-rich fibrin membrane. The primary outcome variable of this study was the radiographic changes to bone height 6 months after augmentation. The secondary outcome variables were the percentage of newly formed bone and the implant survival rate. The data were analyzed with a significance level of α = 0.05.

Results:

Of the 13 patients included, a total of 11 patients (7 females, 4 males; mean age 50.92) completed the study. The mean values of vertical bone gain were 1.72 ± 0.78 mm for the test group and 2.83 ± 0.89 mm for the control group, which constitutes a significant difference ( P = .008). The percentage of newly formed bone was 18.08% ± 2.17% for the test group and 14.26% ± 1.76% for the control group. The difference between the groups was statistically significant ( P < .001). The implant survival rates were 100% for both study groups.

Conclusions:

Based on the study results, screw tent-pole can be considered a feasible technique for bone augmentation. Further randomized studies will be necessary to fully evaluate vertical bone augmentation using the screw tent-pole technique, with different graft materials and with larger samples.

Implant site preparation application of injectable platelet-rich fibrin for vertical and horizontal bone regeneration: A clinical report

Guided bone regeneration (GBR) using a combined injectable platelet-rich fibrin (i-PRF), leukocyte- and platelet-rich fibrin (L-PRF) and biocompatible bone substitute materials, is a convenient and effective method to augment a combined vertical and horizontal bone defect. This approach can create sufficient bone quality and quantity for implant surgical sites. A 55-year-old Asian woman presented with a severe bone defect in posterior mandible. The edentulous mandibular alveolar ridge was severely resorbed vertically and horizontally.  A GBR procedure using i-PRF and L-PRF combined with particulate bone graft was performed. Postoperative cone beam computed tomography scans, 8 months after the augmentation, revealed a large regeneration of the alveolar bone sufficient for implant placement. A combination i-PRF/L-PRF and particulate bone graft may provide biologically active molecules as well as a scaffold for osteogenesis. This treatment protocol may be a viable option for a large bone defect required augmentation prior to implant placement.

Preclinical evaluation of a 3D-printed hydroxyapatite/poly(lactic-co-glycolic acid) scaffold for ridge augmentation

BACKGROUND/PURPOSE

Supracrestal ridge augmentation (SRA) is a major challenge for clinicians. This study investigated the efficacy of a 3D-printed (3DP) hydroxyapatite/poly(lactic-co-glycolic acid) (HA/PLGA) scaffold as a potential biologic for SRA.

METHODS

Scaffolds that were 5 mm in diameter and 2.5-mm thick with a 1.2-mm diameter through-and-through central hole composed of 90% HA and 10% PLGA were printed using an extrusion-based bioprinter. The HA/PLGA scaffold was fixed with a 1.2-mm titanium mini-implant on the buccal surface of rat mandible (Ti-HPS), and the outcome of SRA were compared with sites treated with a titanium mini-implant alone (control) and a titanium mini-implant covered with deproteinized bovine bone-derived matrix (Ti-DBBM) at 4 and 8 weeks by microcomputed tomography (micro-CT), back-scattered SEM, and histology assessments.

RESULTS

The HA/PLGA scaffolds were 2.486 ± 0.082 mm thick with an outer diameter of 4.543 ± 0.057 mm and an inner diameter of 1.089 ± 0.045 mm, and the pore dimensions were 0.48-0.52 mm. There was significantly more mineralized tissue in the Ti-DBBM and Ti-HPS groups than in the control group at both time points. Newly formed bone (NB) was well-integrated with the DBBM and HA/PLGA scaffolds. The framework of the 3DP-HA/PLGA scaffold remained in place, and NB-implant contact (NBIC) was advanced to the middle level in the Ti-HPS group until 8 weeks, whereas dispersion of DBBM with a lower level NBIC was noted in the Ti-DBBM group at both time points.

CONCLUSION

The 3DP HA/PLGA scaffold maintains supracrestal space and demonstrates osteoconductivity to facilitate SRA.

Effect of biologic materials on the outcomes of horizontal alveolar ridge augmentation: A retrospective study

PURPOSE

The purpose of this study was to investigate if the addition of biologic agents to a particulate bone graft enhances horizontal ridge augmentation outcomes in terms of bone dimensions, bone density, and successful implant placement.

MATERIALS AND METHODS

A retrospective chart review was done to assess the clinical and radiographic outcomes in 52 horizontal ridge augmentation sites in 43 patients. Information was gathered regarding surgical technique, type of graft material, biologic agents used (PRP or rhPDGF-BB), method of space maintenance, and achieved alveolar ridge width and bone density changes as quantified on CBCT scans.

RESULTS

The use of tenting screws, a resorbable membrane, and a combination of particulate allogenic and xenogenic bone graft material provided an average horizontal bone gain of 3.6 mm in the 52 augmented sites. There was no statistically significant difference observed in the amount of horizontal bone gain between sites treated with the addition of biologic agents (n = 21), or with a particulate bone graft alone (n = 31). A marginally statistically significant difference was found in the density of the grafted bone with the addition of biologics (p value = .0653).

CONCLUSION

The addition of biologic agents to the graft materials did not have a significant effect on the amount of horizontal bone gain or successful implant placement; however, it marginally enhanced the bone density of the grafted area.

Short Implants: An Answer to a Challenging Dilemma?

The purpose of this article is not to discuss the success of short dental implants versus standard/long dental implants, but to compare short dental implants with standard/long dental implants in areas that necessitated adjunctive bone grafting or augmentation procedures and as a way to avoid the need for advanced surgical procedures and their associated risks. It can be concluded that short dental implants are a viable alternative in sites that would have required additional complex and costly augmentation procedures. Short dental implants resulted in comparable survival and success rates with faster, less expensive treatment with fewer surgical complications and morbidity.

Comparison of in-situ bone ring technique and tent-pole technique for horizontally deficient alveolar ridge in the anterior maxilla

BACKGROUND

Limited studies focused on the bone profile maintenance at the alveolar ridge crest applying horizontal bone augmentation.

PURPOSE

A novel approach named as "in-situ bone ring technique" was introduced to be compared with tent-pole technique to evaluate their horizontal bone gain, resorption, and postoperative perception.

MATERIALS AND METHODS

A total of 30 patients were included in this retrospective cohort study. All patients required horizontal bone augmentation at anterior site. Accordingly, quantitative and qualitative analyses were conduct radiographically and histologically between in-situ bone ring (ring group) and tent-pole technique (tent group). Moreover, the visual analog scale (VAS) was introduced to assess the patients' perception toward both treatments.

RESULTS

Cone-beam computed tomography results showed great significant difference regarding horizontal bone width at 0 mm and 3 mm from alveolar ridge crest between two groups (P < .05). On the basis of histological outcomes, delightful bony fusion was shown 6-month postoperatively in ring group. The VAS ratings for pain and swelling reflected similar results between two groups.

CONCLUSIONS

In-situ bone ring technique evidently increased and maintained horizontal bone mass at the alveolar ridge crest compared to tent-pole technique, which might be favorable for implant rehabilitation in anterior area. Meanwhile, no further discomfort was caused according to VAS scoring between two groups.

Bone Augmentation Techniques for Horizontal and Vertical Alveolar Ridge Deficiency in Oral Implantology

Bone deficiency is the major obstacle in implant dentistry. Guided bone regeneration (GBR) with particulate bone and barrier membranes has been the primary surgical technique used to regenerate alveolar bone for dental implant therapy. This procedure has been used in implant dentistry for more than 30 years and continues to be developed and refined for more predictable surgical outcomes. This article reviews GBR and alternative ride expansion procedures and reviews the use of various particulate graft materials. Alveolar distraction osteogenesis, used as an augmentation technique, is also presented.

Vertical Guided Bone Regeneration with Mineralized Cancellous Bone Allograft in a Severe Anterior Maxillary Defect: A Clinical Report with 14-Year Follow-Up

Purpose

To report the supracrestal bone regeneration of approximately 10 mm using solvent-dehydrated mineralized cancellous bone allograft and nonresorbable membrane in rehabilitation of unsuccessful implants in the anterior maxilla and stability of the regenerated bone at the 14th-year follow-up.

Case Presentation

A 24-year-old female patient with a history of anterior dentoalveolar trauma resulting in the loss of upper left incisors and canine underwent rehabilitation several years ago with three implant-supported fixed prostheses. The prosthesis was both functionally and aesthetically inadequate, and the patient complained of gingival swelling, bleeding, and food impaction at the site of the implants. A staged approach for retreatment was planned, wherein the first surgical stage aimed at removing the existing implants and preparing the bone ridge and soft tissues for the augmentation procedure. The second stage was vertical ridge augmentation and simultaneous prosthetic-driven placement of two new implants at the sites of the left central incisor and canine. After nine months of uneventful healing, complete regeneration of the bony defect was achieved, and the new prosthetic rehabilitation satisfied both functional and aesthetic requirements.

Conclusion

The therapeutic approach followed in the present case proved effective in achieving satisfactory functional and aesthetic results and in maintaining the stability of the regenerated bone at 14 years of follow-up.

Mechanical Characterization of 3D-Printed Individualized Ti-Mesh (Membrane) for Alveolar Bone Defects

Individualized titanium mesh holds many advantages over conventional mesh. There are few reports in the literature about the effect of mesh pore size and mesh thickness on the mechanical properties of titanium mesh. This study is designed to develop an individualized titanium mesh using computer-assisted design and additive manufacturing technology. This study will also explore the effect of different thicknesses and pore sizes of titanium mesh on its mechanical properties through 3D FEA. According to this study, the mechanical properties of titanium mesh increased when the thickness decreased (0.5 mm to 0.3 mm). With an increase in mesh diameter (3 mm to 5 mm), the mechanical properties of mesh decreased. The diameter of titanium mesh has less influence on its mechanical properties than does the thickness of the mesh. Titanium mesh with a thickness of 0.4 mm is strong enough and causes less stimulation to mucosa; therefore, it is more suitable for clinical use. In addition, parameters of titanium mesh should be decided clinically according to bone defect size, defect location, and force situation.

Growth Dynamic of Allogeneic and Autogenous Bone Grafts in a Vertical Model

Several techniques have been proposed for vertical bone regeneration, and many of them use bone autogenous and allogeneic grafts. The purpose of this study was to compare demineralised freeze-dried bone allografts (DFDBA), fresh-frozen (FF) allografts, autogenous bone grafts to find differences between volumetric and histological quantity of bone formation and vertical bone growth dynamic. A vertical tissue regeneration bone model was performed in rabbit calvarias under general anaesthesia. Four hollow cylinders of pure titanium were screwed onto external cortical bone calvarias in eight rabbits. Each one of the cylinders was randomly filled with one intervention: DFDBA, FF, autogenous bone, or left to be filled with blood clot (BC) as control. Allogeneic grafts were obtained from a ninth animal following international standardised protocols for the harvesting, processing, and cryopreservation of allografts. Autogenous graft was obtained from the host femur scraping before adapting hollow cylinders. Animals were euthanized at 13 weeks. Vertical volume was calculated after probe device measurements of the new formed tissue inside the cylinders and after titanium cylinders were removed. Histomorphometry and fluorochrome staining were used to analyse quantity and dynamic of bone formation, respectively. Results showed that DFDBA and fresh-frozen bone improved the velocity and the quantity of bone deposition in distant portions of the basal plane of grafting. Remaining material in allograft groups was more intense than in autogenous group. Both allografts can be indicated as reliable alternatives for volume gain and vertical bone augmentation.

Cell therapy induced regeneration of severely atrophied mandibular bone in a clinical trial

Background

Autologous grafting, despite some disadvantages, is still considered the gold standard for reconstruction of maxillofacial bone defects. The aim of this study was to evaluate bone regeneration using bone marrow-derived mesenchymal stromal cells (MSCs) in a clinical trial, a less invasive approach than autologous bone grafting. This comprehensive clinical trial included subjects with severe mandibular ridge resorption.

Methods

The study included 11 subjects aged 52–79 years with severe mandibular ridge resorption. Bone marrow cells were aspirated from the posterior iliac crest and plastic adherent cells were expanded in culture medium containing human platelet lysate. The MSCs and biphasic calcium phosphate granules as scaffolds were inserted subperiosteally onto the resorbed alveolar ridge. After 4–6 months of healing, new bone formation was assessed clinically and radiographically, as were safety and feasibility. Bone at the implant site was biopsied for micro-computed topography and histological analyses and dental implants were placed in the newly regenerated bone. Functional outcomes and patient satisfaction were assessed after 12 months.

Results

The bone marrow cells, expanded in vitro and inserted into the defect together with biphasic calcium phosphate granules, induced significant new bone formation. The regenerated bone volume was adequate for dental implant installation. Healing was uneventful, without adverse events. The patients were satisfied with the esthetic and functional outcomes. No side effects were observed.

Conclusions

The results of this comprehensive clinical trial in human subjects confirm that MSCs can successfully induce significant formation of new bone, with no untoward sequelae. Hence, this novel augmentation procedure warrants further investigation and may form the basis of a valid treatment protocol, challenging the current gold standard.

Trial registration

EudraCT, 2012-003139-50. Registered on 21 August 2013. ClinicalTrials.gov, NCT 02751125. Registered on 26 April 2016.

Tentpole technique for bone regeneration in vertically deficient alveolar ridges: A prospective study

Purpose

The purpose of the study was to qualitatively and quantitatively assess bone regeneration potential of tentpole technique using beta tricalcium phosphate bone graft in vertically deficient alveolar ridges.

Materials and Method

This prospective study comprised of 20 patients with vertically deficient alveolar ridges, wherein thirty one implants were placed. Tenting of the soft tissue matrix was done using titanium screws and beta tricalcium phosphate synthetic bone graft was filled in the vertical defect. Clinical and radiographic assessment was done at 1, 3 and 6 months. Preoperative biochemical analysis of Osteopontin and RANKL was done and then reassesed at 3 months postoperative. Bone core collected at 6 postoperative months, while removal of screw, was analysed histologically.

Results

A significant gain in bone height of 2.87 ± 0.79 mm was seen at 6 months postoperative. All implants osseointegrated. Loosening of screw was seen in two patients.There was no postoperative wound dehiscence. Histologic analysis revealed new bone formation .There was no significant change in the levels of RANKL and Osteopontin at 3 months postoperative.

Conclusion

This is a safe and effective technique for bone regeneration in vertically deficient alveolar ridges and has minimal complications. The regenerated bone has new and viable bone content and supports implant material. More studies with long term follow up are needed to assess the stability of bone after long term loading.

Treatment of Severely Resorbed Maxilla Due to Peri-Implantitis by Guided Bone Regeneration Using a Customized Allogenic Bone Block: A Case Report

The objective of this case report is to introduce a customized CAD/CAM freeze-dried bone allograft (FDBA) block for its use in Guided Bone Regeneration (GBR) procedures for severely deficient maxillary bones. Additionally, a special newly developed remote incision technique is presented to avoid wound dehiscence. The results show optimal integration behavior of the FDBA block after six months and the formation of new vital bone. Thus, the results of the present case report confirm the use of the customized CAD/CAM bone block for augmentation of complex defects in the maxillary aesthetic zone as a successful treatment concept.

How Effective Is the Tent Screw Pole Technique Compared to Other Forms of Horizontal Ridge Augmentation?

PURPOSE

The tent screw pole technique is one of the methods available for practitioners to perform horizontal ridge augmentation to facilitate dental implant placement. The purpose of this study was to evaluate the efficacy of the tent screw pole technique for horizontal ridge augmentation and to compare the results with those of the tunnel technique and open ridge augmentation.

PATIENTS AND METHODS

In this retrospective cohort study, 35 patients underwent horizontal ridge augmentation with the tent screw pole technique, a 1:1 ratio of mineralized freeze-dried bone allograft and particulate bovine hydroxyapatite, and a resorbable collagen membrane. The incidence of early wound dehiscence and membrane exposure, the number of courses of antibiotics and postoperative visits required for their management, and the number of sites that subsequently had successful implant placement were recorded. These parameters were compared with those in 21 patients who had undergone horizontal ridge augmentation by the tunnel technique and 31 patients who had been treated using an open procedure and a resorbable polytetrafluoroethylene (PTFE) membrane in the authors' previous study (J Oral Maxillofac Surg 74:1752, 2016).

RESULTS

Implant placement rate was similar for all 3 methods (71 to 97%). However, there were significant differences among the 3 surgical techniques for membrane exposure and wound dehiscence (P = .0033), graft loss (P = .0256), courses of antibiotics (P = .0017), and postoperative visits (P = .0043). The PTFE method consistently had the highest rate of complications, whereas the tent screw and tunnel techniques were comparable.

CONCLUSIONS

All 3 techniques allowed a high rate of implant placement; however, the PTFE technique was consistently associated with increased postoperative complications compared with the other 2 methods. The tent screw technique might be more favorable than the tunnel technique in cases in which the bony deficiency is flat.

Long-term effects of vertical bone augmentation: a systematic review

Extraction, periodontitis, or trauma can cause a reduction on the alveolar ridge. This could result in an insufficient alveolar bone width and height. Different techniques of vertical bone augmentation are described in literature. However, nowadays there is not enough evidence against lateral augmentation procedures to verify if these techniques are stable over a long period of time.

Treatment of Labial Soft Tissue Recession Around Dental Implants in the Esthetic Zone Using Guided Bone Regeneration With Mineralized Allograft: A Retrospective Clinical Case Series

PURPOSE

Soft tissue augmentation procedures are often performed to correct gingival recession on the facial aspects of implants in the esthetic zone. This retrospective clinical case series reports on the use of guided bone regeneration (GBR) and a coronal advancement flap with a resorbable membrane and allograft.

MATERIALS AND METHODS

We analyzed the records of 14 patients (7 men and 7 women) with a mean age of 36.78 years (SD, 13.9 years) who were treated for soft tissue recessions around implant-supported restorations in the maxillary central or lateral incisor location. Implant diameters ranged from 3.3 to 4.7 mm. All patients had bone loss confined to the labial surface of the implant. A solvent-dehydrated particulate mineralized allograft (Puros Cancellous Bone Allograft; Zimmer Biomet Dental, Palm Beach Gardens, FL) and a resorbable membrane (CopiOs Pericardium; Zimmer Biomet Dental) were used in a GBR surgical procedure in combination with a roughened titanium tenting screw placed 3 to 4 mm below the implant platform to restore unesthetic defects in the anterior maxilla.

RESULTS

All postoperative tissue changes from their preoperative states were statistically significant (P < .05, Wilcoxon signed rank test). Mean preoperative crestal bone thickness (measured 2 mm from crest) and mid-implant buccal bone thickness increased by 1.84 mm (SD, 0.89 mm; 95% confidence interval [CI], 1.32 to 2.35 mm) and 2.07 mm (SD, 0.81 mm; 95% CI, 1.60 to 2.53 mm), respectively, approximately 1 year after treatment (P < .001). Significant mean increases of 1.28 mm (SD, 0.53 mm; 95% CI, 0.97 to 1.58 mm), 1.29 mm (SD, 0.81 mm; 95% CI, 0.82 to 1.75 mm) and 1.23 mm (SD, 0.53 mm; 95% CI, 0.92 to 1.53 mm) also were noted in soft tissue thickness, keratinized tissue width, and gingival height, respectively (P < .001).

CONCLUSIONS

Use of the allograft and xenogeneic membrane effectively increased alveolar hard and soft tissue dimensions in the esthetic zone of the anterior maxilla. Future prospective clinical trials with a control group are needed to compare this technique with conventional methods such as connective tissue graft.

Alveolar ridge preservation with deproteinized bovine bone graft and collagen membrane and delayed implants

To evaluate clinically and radiographically an alveolar ridge, preservation technique with deproteinized bovine bone graft and absorbable collagen membrane and then restoration with delayed implants were done. The study included 30 patients. The trial group's sockets were filled with deproteinized bovine bone graft (Bio-Oss) and covered with absorbable collagen membrane (Bio-Gide). The control group's sockets healed without any treatment. Panoramic radiograph and computed tomography were taken immediately after graft and 3 and 6 months later to evaluate the height, width, and volume change of the alveolar ridge bone. Dental implants were inserted in all sockets at 6 months, and osseointegration condition was evaluated in the following 12 months. All sockets healed uneventfully. In the trial group, the mean (SD) height reduction of the alveolar ridge bone was 1.05 (0.24) mm at 3 months and 1.54 (0.25) mm at 6 months. The width reduction was 1.11 (0.13) mm at 3 months and 1.84 (0.35) mm at 6 months. Bone volume reduction was 193.79 (21.47) mm at 3 months and 262.06 (33.08) mm at 6 months. At the same trend, in the control group, the bone height reduction was 2.12 (0.15) mm at 3 months and 3.26 (0.29) mm at 6 months. The width reduction was 2.72 (0.19) mm at 3 months and 3.56 (0.28) mm at 6 months. Bone volume reduction was 252.19 (37.21) mm at 3 months and 342.32 (36.41) mm at 6 months. There was a significant difference in alveolar ridge bone height, width, and volume reduction in the 2 groups. The osseointegration condition had no significant difference between the 2 groups. This study suggested that the deproteinized bovine bone graft and absorbable collagen membrane were beneficial to preserve the alveolar ridge bone and had no influence on the osseointegration of delayed implant.

The Role of Two Different Collagen Membranes for Dehiscence Defect Around Implants in Humans

The aim of this study was to elucidate the role of 2 types of collagen membranes (cross-linked vs noncross-linked) used in conjunction with autogenous or allogenic bone followed by xenogeneic bone particles for dehiscence defect around implants in humans. Experimental groups were divided into 2 groups: Group CL (cross-linked, Ossix Plus, n = 24 implants, 16 patients) and Group NCL (noncross-linked, Bio-Gide, n = 25 implants, 18 patients). At the time of implant insertion and uncovery surgery, measurements of the dehiscence bony height, width, and surface area were made. Before applying the membrane to defects, guided bone regeneration was performed. Because it is difficult to measure the degree of exposure, early exposed cases were excluded from the result analysis. The mean percentage gain of the dehiscence defect and the mean marginal bone reduction value of follow-up radiograph did not show statistically significant differences between the 2 groups. Both membranes exhibited satisfactory results on dehiscence defects. As a result, our authors concluded the success of guided bone regeneration was performed simultaneously for dehiscence defects around the implant, regardless whether collagen membranes were cross-linked or noncross-linked.

Tentpole technique for bone regeneration in vertically deficient alveolar ridges: A review

BACKGROUND AND OBJECTIVES

Vertical augmentation is necessary in cases of extensive resorption of alveolar ridge for dental implants placement and esthetic prosthetic rehabilitation. Several surgical techniques have been used to increase bone height including distraction osteogenesis, and particulate or block bone graft. This study was done to describe the evolution of "tentpole technique" and to review the literature related to this technique and thus evaluate its effectiveness to augment large vertical alveolar ridge defects for implant placement.

MATERIAL AND METHODS

The evidence was obtained by PubMed and Google search using key words: tentpole technique, ridge resorption, and alveolar ridge augmentation . The years of search included from 2002 till 2013.

RESULTS

The technique was described as effective on review of outcome of existing studies. It was found that considerable and stable increase in alveolar ridge height was achieved using tentpole technique.

CONCLUSIONS

Tenting of periosteum and soft tissue matrix maintains space and enhances the effectiveness of bone graft. This technique offers predictable functional and esthetic reconstruction of large vertical alveolar defects.

Clinical Importance of Recipient Site Characteristics for Vertical Ridge Augmentation: A Systematic Review of Literature and Proposal of a Classification

This review evaluated the characteristics of vertical alveolar defects that were augmented via onlay bone grafting or guided bone regeneration. Information regarding the anatomic site, type of edentulism, and defects' dimensions were extracted. The experiments differed vastly in the description of the defects' features. Aiming to mitigate the confounding effect of recipient site's morphology in future experiments, a classification of vertically deficient recipient sites is proposed.

Phenotypic characterization of mononuclear inflammatory cells following equine hydroxyapatite/collagen block grafting in rats

To measure the inflammatory changes associated with the implantation of an equine hydroxyapatite and collagen-containing block graft (eHAC block) in a rodent model system, an eHAC block graft was implanted subcutaneously in rats. Control groups included saline, turpentine oil, and human mineralized particulate allograft (hMPA). Animals were sacrificed and tissue samples obtained after three days, as well as after 1, 2, 4 and 8 weeks. A panel of immunologic probes was used to identify circulatory monocytic cells (ED1), resident mononuclear phagocytes (ED2), mononuclear phagocytes of lymphoid origin (ED3), expression of Ia antigen (OX6), T-cells (OX19), and B-cells (OX33). Immunocytochemical localization was performed and mononuclear cells localized with each immunologic probe counted. Rat sera obtained after eight weeks were used for nitrocellulose dot-blotting to assess circulating anti-equine immunoglobulins. Statistical analysis was performed using two-way analysis of variance, in conjunction with the Bonferroni correction to account for multiple comparisons. A transient increase in monocytes at 3 days and 1 week was observed in all groups, but was significantly higher in the turpentine control (P < 0.0001). A significant increase in the numbers of mononuclear cells detected with clones ED2 and ED3 was observed in specimens from the turpentine group, in contrast to the other groups in the 3 day to 4 week interval (P < 0.0001), as well as within all time periods (P < 0.0001). A statistically significant difference in numbers of ED3-positive cells was observed in the hMPA group compared to the saline and the eHAC block groups after one week (P < 0.0001). Significantly more OX6-positive cells were observed in the turpentine group, compared to other groups (3 days to 1 week; P < 0.0001). T-lymphocytes were essentially absent except for rats given turpentine (after 1 week). No B-lymphocyte response was found and none of the rats developed systemic anti-equine antibodies. These data indicate that a cellular immune response is not elicited following implantation with the eHAC block graft, which might serve as an alternative material for regenerative therapy.