Atrophic Edentulous Ridges Research Articles

All-on-four treatment with narrow platform implants in reduced restorative space for moderate atrophic edentulous ridge

All-on-four treatment with narrow platform implants in reduced restorative space for moderate atrophic edentulous ridge

English

This article describes the fabrication of a hollow maxillary complete denture using silicone putty and a double flask technique. A successful complete denture directly depends on retention, stability and support accompanied by good aesthetics. However, in case of atrophic edentulous ridges the challenge lies in the fact that there is a significantly lesser denture bearing area that can lead to a number of problems. The most important of these is an increased interarch space resulting from excessive resorption of upper or lower arch. This can lead to a resulting heavy complete denture that further deteriorates the bone condition due to excessive and continuous load, accelerating bone resorption. Moreover, there is no effective support to deal with any kind of harmful lateral forces and this can lead to dislodgment of the denture. The operator’s efficiency lies in applying the basic principles of fabricating a denture and innovating various steps to counter critical situations. Various methods such as asbestos, silicone putty, modelling clay, thermocol, salt, wax have been used for creating a hollow space inside the denture. Out of the various methods that have been used for fabrication of a hollow space inside a complete denture, silicone putty method is one of the more convenient and accurate method for achieving the objective, thereby rendering a lighter prosthesis. A hollow maxillary denture is highly advantageous as it reduces the weight of acrylic resin, thereby preserving the residual alveolar ridge. It also helps in stability of the denture by indirectly reducing the lateral forces.

Customized CAD/CAM titanium meshes for the guided bone regeneration of severe alveolar ridge defects: Preliminary results of a retrospective clinical study in humans

To present the results of guided bone regeneration (GBR) of atrophic edentulous ridges with customized CAD/CAM titanium meshes. Forty-one patients, presenting with 53 atrophic sites, were enrolled between 2018 and 2019. GBR was obtained with titanium meshes filled with autogenous bone chips and bovine bone mineral (BBM). After a mean of 7months (range: 5-12months), meshes were removed and 106 implants placed. After a mean of 3.5months (range: 2-5months), implants were uncovered and prosthetic restorations started. The outcomes were vertical and horizontal bone augmentation changes, biological complications and implant survival. Out of 53 sites, 11 underwent mesh exposure: eight of them were followed by uneventful integration of the graft, while three by partial bone loss. The mean vertical and horizontal bone gain after reconstruction was 4.78±1.88mm (range 1.00-8.90mm) and 6.35±2.10mm (range 2.14-11.48mm), respectively. At the time of implant placement, mean changes of initial bone gain were -0.39±0.64mm (range -3.1 to+0.80mm) and -0.49±0.83mm (range -3.7 to +0.4mm), in the vertical and horizontal dimensions, respectively. Reduction of bone volume was significantly higher (p<.001 for both dimensions) in the exposed sites. The mean follow-up of implants after loading was 10.6±6.5months (range: 2-26months). The survival rate of implants was 100%. Customized titanium meshes can represent a reliable tool for GBR of severely atrophic sites, with simplification of the surgical phases.

Evaluation of Stress and Strain Magnitude in Tapered and Cylindrical Implant Surrounding Bone, Used for Restoration of Mandibular Teeth: Finite Element Analysis in All-on-Four Concept.

The prevalence of the elderly population increased in the 20th century, as described in the World Health Organization 2004 Annual Report. The use of tilted implants parallel to the anterior wall of the maxillary sinus or the mental foramen/inferior alveolar nerve has been proposed for the treatment of the atrophic edentulous ridge. The aim of this study was to evaluate stress and strain magnitude in tapered and cylindrical surrounding bones. A 3D finite element model of an edentulous mandible was constructed. Two models of implants were used: cylindrical and tapered BEGO Semados RI Implants. Four implants were inserted between the bilateral mental foramen according to All-on-Four concept, and a mandibular bar was designed to use with the All-on-Four bar supported models. A vertical and 30 degree vertical load of 100 N was applied to both cylindrical and tapered implants models. Strain and stress were analyzed with ANSYS software (ANSYS R18.0). The maximum stress and strain were applied in all axes for the posterior man-dibular areas in the crestal region of the bone, and for the anterior areas at the intraosseous contact site. Also, the stress and strain of the bone under force in all axes in all areas for tapered implants is less compared to that for cylindrical implants. We found that the highest rate of bone resorption occurs in the posterior areas near the junction of the fixture with the abutment of implant, and in the anterior areas near the end of the fixture of implant. Still, more research on the subject is needed.

GBR of atrophic edentulous ridges with customized CAD‐CAM titanium meshes: a prospective study

GBR of atrophic edentulous ridges with customized CAD‐CAM titanium meshes: a prospective study

Occlusal reconstruction of a patient with ameloblastoma ablation using alveolar distraction osteogenesis: a case report

BackgroundAmeloblastoma is one of the most common benign odontogenic neoplasms. Its surgical excision has the potential to lead to postoperative malocclusion. In this case report, we describe the successful interdisciplinary orthodontic treatment of a patient with ameloblastoma who underwent marginal mandibulectomy.Case presentationA woman of 20-year-old was diagnosed with ameloblastoma, and underwent marginal mandibulectomy when she was 8 years of age. She had an excessive overjet (11.5 mm) and a mild open bite (− 1.5 mm) with a severely resorbed atrophic edentulous ridge in the area around the mandibular left lateral incisor, canine and first premolar. An alveolar bone defect associated with tumor resection was regenerated by vertical distraction osteogenesis (DO). Subsequently, 3 dental implants were placed into the reconstructed mandible. Orthodontic treatment using implant-anchored mechanics provided a proper facial profile with significantly improved occlusal function. The occlusion appeared stable for a 7-year retention period.ConclusionsThese results suggest that surgically assisted and implant anchored-orthodontic approaches might be effective for the correction of such malocclusions.

Lateral and apical root resorption in teeth orthodontically moved into edentulous ridge areas.

ABSTRACTObjective: The present study aimed at comparing the external lateral root resorption (ELRR) and external apical root resorption (EARR) between teeth moved through the atrophic edentulous ridge and those undergoing the usual orthodontic movement. Methods: Fifty-four premolars were evaluated, where 27 of them had been moved toward the edentulous ridge (Group 1) and 27 from the same patient, had not been translated, which comprised the control group (Group 2). ELRR was evaluated by 0-3 scores and EARR was evaluated by 0-4 scores, before and after movement. Measurements were compared by Kruskal-Wallis and Student-Newman-Keuls tests. Results: ELRR increased statistically only in the Group 1 (p< 0.05). After orthodontic treatment, it was observed that almost 56% (n = 15) of teeth in Group 1 presented scores 2 and 3, while Group 2 presented scores 2 and 3 in about 11% (n= 3) of the teeth. EARR increased in both groups after orthodontic movement, however, statistically analyses showed no significant differences between groups (p> 0.05). Conclusions: Orthodontic movement into the atrophic edentulous ridge is subject to a greater lateral external root resorption.

A cross sectional study of dental implant service provision in British and Irish dental hospitals.

Introduction There are multiple ways in which treatment using dental implants is provided in a secondary care setting, not only in terms of the groups of patients treated, but also the clinicians who provide that care.Methods An online survey was circulated to speciality registrars in restorative dentistry in all UK dental hospitals and to postgraduate students in prosthodontics in the Republic of Ireland, consisting of nine questions aimed at understanding which patient groups are treated using dental implants in a hospital setting, how cases are planned, executed and to explore the underlying reasons for each unit's method of provision.Results Completed surveys were received from 67% of dental hospitals in Britain and Ireland. Treatment planning was undertaken by the restorative team alone in 64% of units in patients with hypodontia, 57% with trauma and 71% with an atrophic edentulous ridge and by a multi-disciplinary team in 50% of units for patients with cleft lip and palate (CLP) and 45% with head and neck (H&N) cancer. The restorative team place all or most of the implant fixtures in 50% of units in patients with CLP, 71% in trauma patients, 71% in hypodontia patients, 64% in edentulous patients and 43% in H&N oncology patients. Stents are produced and used by the restorative team in 64% of units for edentulous patients, 79% of patients with hypodontia, 79% of those suffering trauma, 58% of CLP patients and 50% of patients with H&N cancer. Twenty-one percent of responding units had stents made by the restorative team and used by the surgical team. The median percentage of implant-supported restorations that are screw retained is 90% (SD: 4.93, range: 25-95%) and the median percentage of zirconia abutments being used is 22.5% (SD: 5.24, range: 0-50%). Use of zygomatic implants varies hugely between responding units with 43% of them not placing any zygomatic implants.Conclusions There is a wide range of protocols and team members involved in the provision of dental implant rehabilitations throughout the British Isles reflecting the lack of any single evidence-based approach. A multi-disciplinary team approach with the restorative dentist as a key member is likely to yield the most favourable long term outcomes.

Reconstruction of severely atrophic edentulous ridges with autogenous onlay bone grafts

Reconstruction of severely atrophic edentulous ridges with autogenous onlay bone grafts

Restructuring of dental implant education in India

Various treatment modalities have been proposed and practiced over the years for comforting the functions of individuals with enhanced life expectancy leading to an aging population. These therapeutic modalities are directed toward providing masticatory apparatus to patients with atrophic edentulous ridges. After evolving over several years, clinicians have now been enabled to use dental implants and provide a functionally viable and esthetically pleasing masticatory apparatus to their patients. However, majority of the dentists lack the detailed knowledge, skills, and experience which are necessary and essential for a successful implant therapy. Various training programs have been conducted across the country with the motive to bridge the gap between the clinician and the therapy. However, the existing training programs and courses lack the detailed theoretical inputs and deliberations, which form the very basis for an implicative understanding of the therapeutic modality and thus do not offer desired outcomes many a times. The success of implant therapy depends not only merely in achieving osseointegration of the implant but also providing the esthetic and functional standards, which are in tune with the patient's expectation. Oral implantology cases can be briefly divided based on their complexity as either straightforward or complex placement and/or restoration of implant. To benefit the society at large, it is high time that training programs be proposed with differential skill upgradation with different avenues. The article proposes a few training avenues for the dental professionals which if taken up in the right perspective will restructure the education in oral implantology in our country. Such training avenues need to be brought under regulatory bodies such as the State Health Universities and Dental Council of India so as to achieve a desired standardization and uniformity.

Long-term Evaluation of Peri-implant Bone Level after Reconstruction of Severely Atrophic Edentulous Maxilla via Vertical and Horizontal Guided Bone Regeneration in Combination with Sinus Augmentation: A Case Series with 1 to 15 Years of Loading.

To the best of the authors' knowledge, there is very limited clinical data on the outcomes of simultaneous guided bone regeneration (GBR) for horizontal and/or vertical bone gain for the reconstruction of severely atrophic edentulous maxilla. Therefore, the purpose of the clinical series presented herein was to clinically evaluate long-term horizontal and vertical bone gain, as well as implant survival rate after reconstruction of severely atrophic edentulous maxillary ridges. Sixteen patients (mean age: 64.6 ± 14.6 years of age) were consecutively treated for vertical and/or horizontal bone augmentation via GBR in combination with bilateral sinus augmentation utilizing a mixture of autologous and anorganic bovine bone. Implant survival, bone gain, intraoperative/postoperative complications and peri-implant bone loss were calculated up to the last follow-up exam. Overall, 122 dental implants were placed into augmented sites and have been followed from 12 to 180 months (mean: 76.5 months). Implant survival was 100% (satisfactory survival rate of 97.5%). Mean bone gain was 5.6 mm (max: 9 mm; min: 3 mm) While vertical bone gain was 5.1 ± 1.8 mm; horizontal bone gain was 7.0 ± 1.5 mm. No intraoperative/postoperative complications were noted. Mean peri-implant bone loss values were consistent within the standards for implant success (1.4 ± 1.0 mm). At patient-level, only one patient who had three implants presented with severe peri-implant bone loss. Complete reconstruction of an atrophied maxilla can be successfully achieved by means of guided bone regeneration for horizontal and/or vertical bone gain including bilateral sinus augmentation using a mixture of anorganic bovine bone and autologous bone.

Platelet-rich fibrin, a physiological concentrate in the management of buccal dehiscence of implant – A case report

IntroductionSuccessful implant dentistry is based on proper selection of patients, careful surgery, preplanned restorations, and postoperative and supportive care. Although implant therapy is highly successful and predictable, it is not without early and/or late complications. Placement of dental implants in narrow or atrophic edentulous ridges often leads to complications, such as dehiscence and fenestration.1 Case reportThis case report presents the successful management of buccal dehiscence of single-staged implant for replacement of left central incisor with the platelet-rich fibrin (PRF) and autogenous bone graft material. The initial mobility was completely resolved after 12 weeks and final restoration was given to patient. DiscussionThe treatment for dehiscence requires the use of various regenerative procedures but PRF belongs to a new generation of platelet concentrates geared to simplify preparation without biochemical blood handling.2 Adjunctive implantation of PRF does appear to significantly improve the healing response, which has resulted in rapid, clinically relevant bone closure of dental implant dehiscence defect in the present case.

Mandibular Overdentures Retained by Two Mini-Implants: A Seven-Year Retention and Satisfaction Study.

Patients with atrophic edentulous ridges generally have problems with retention, therapeutic satisfaction, and comfort with their complete dentures. An alternative treatment to assist in improving retention and stability involves the use of mini-implants. The aim of this study was to evaluate the retention of mandibular overdentures connected to two mini-implants and overall patient satisfaction with them. Seven patients with atrophic mandibular ridges (Type 4D Misch classification), aged 62 to 74 years old were rehabilitated with complete dentures. In each patient, two mini-implants measuring 15 or 13 mm in length and 1.8 mm in diameter were placed. After 15 days, overdentures were connected to the mini-implants with O-ring attachments. In each patient, retention of the overdentures was measured, and a survey of therapeutic satisfaction before and after connection to the mini-implants was administered. Prosthesis retention was measured with a digital dynamometer at 1 month, 6 months, and 2, 3, 5, and 7 years after mini-implant placement. Patient satisfaction was assessed with a survey. Data were analyzed with Student's t-test (satisfaction survey) and the Friedman test (retention measurements and satisfaction survey). The initial retention values (0.34 to 0.63 N without mini-implants) varied significantly (p ≤ 0.050). These values were less than the subsequent measurements of 3.92 to 9.64 N, taken after placement of the mini-implants and connecting them to the dentures. Satisfaction was good to very good over the 7-year observation period. Mucosa and peri-implant bone showed no pathological changes. In this limited sample size clinical study the results indicated that after connecting mandibular overdentures to two mini-implants, patient satisfaction significantly increased and retention significantly improved during the 7-year observation period.

A Partial Palatal Coverage Overdenture Retained by Zygomatic Implants.

Prosthodontic rehabilitation of an atrophic edentulous maxilla can be challenging and is further complicated when multiple risk factors are present. Fixed prostheses require multiple implants for support/retention organized in biomechanically favorable positions in order to afford a good prognosis. Such suitable implant arrangements in an atrophic edentulous ridge can often be difficult to achieve. Removable prostheses require fewer implants for a favorable prognosis and can furthermore take advantage of the additional anatomical structures for support/retention. This clinical treatment will describe the fabrication of a partial palatal coverage overdenture retained by zygomatic implants.

Clinical Outcome of the Use of Fresh Frozen Allogeneic Bone Grafts for the Reconstruction of Severely Resorbed Alveolar Ridges: Preliminary Results of a Prospective Study

The objectives of this study were to evaluate: (1) the clinical outcome of fresh frozen human allogeneic bone grafts (FFB) used for the reconstruction of severely atrophied edentulous ridges; (2) the survival rate of implants placed in the reconstructed areas; and (3) bone resorption. During a 2-year period, 19 patients with severely atrophied partially or totally edentulous ridges who were candidates for an implant-supported prosthesis were consecutively enrolled and reconstructed with FFB iliac blocks. Five to 7 months later, 117 implants were placed in the reconstructed areas, and prosthetic rehabilitation was started 5 to 6 months afterward. The mean follow-up of patients after prosthetic loading was 27 months (range, 20 to 32 months). Prior to implant placement, graft exposure with partial or total loss of the graft occurred in four patients. After implant placement, bone graft exposures with partial loss of the grafts occurred in nine patients; in two patients, both grafts and implants were removed. The cumulative survival rate of implants was 90.2%. The mean (± standard deviation) graft resorption before implant placement was 0.98 ± 0.77 mm (range, 0 to 4 mm), while these values were 1.21 ± 1.05 mm (range, 0 to 6 mm) at loading, 1.55 ± 1.57 mm (range, 0 to 8 mm) at 12 months, and 1.93 ± 1.38 mm (range, 1 to 9 mm) at 24 months. Within the limits of this study (limited sample of patients and short follow-up), the reconstruction of severely atrophic edentulous ridges with FFB is associated with a relevant incidence of bone exposures and partial or total loss of the grafts, which may compromise the long-term survival of implants placed in the reconstructed areas.

A Minimal Invasive Prosthetic Solution for Small, Atrophic Edentulous Arches Using Narrow Diameter Implant and Magnetic Overdenture: A Case Report

The rehabilitation of the fully edentulous patients could be compromised due to their diversity in terms of clinical, medical, anatomical and economic situations. Typically, narrow and atrophic edentulous ridges complicate retention, support and stability. Overdenture using attachment or implants could help the improvement of denture function and recommended due to its relative simplicity, predictability and affordability. In this report, a short stature patient under medically and physically handicapped was treated as minimal invasive prosthetic intervention using single magnetic attachment (Magfit<SUP>®</SUP>) on the maxilla and 2 freestanding mini-implants (LODI<SUP>®</SUP>) placed in mandible following recommendations from the 2002 McGill. For 12 months following up, patient is satisfied with the final results in functional aspects and esthetic.

Complications and Outcomes of Sinus Augmentation Procedures Using the Lateral Window Approach

Sinus floor augmentation is a widely performed and highly predictable procedure for reconstructing the resorbed atrophic edentulous ridge of the posterior maxilla and restoring function by means of endosseous implants.1 Currently, the lateral window approach is considered to be the gold standard approach to increase the height and width of the available bone in the posterior maxilla.2 There are, however, potential complications associated with this approach that would be expected, like any other surgical procedure.

The role of pericranium grafts in the reduction of postoperative dehiscences and bone resorption after reconstruction of severely deficient edentulous ridges with autogenous onlay bone grafts

To compare: (i) the incidence of soft tissue dehiscences; (ii) bone resorption before and after implant placement; and (iii) the survival and success rates of implants placed in two groups of patients with severe bone defects of the jaws reconstructed with autogenous onlay bone grafts alone (control group) or in association with autogenous pericranium coverage (study group). Forty-four patients affected by severe atrophy of the alveolar ridges underwent bone reconstruction with vertical/tridimensional autogenous onlay grafts harvested from the calvarium or the mandibular ramus. In 23 patients (study group), grafts were covered with autogenous pericranium before suturing, while in 21 patients (control group) no coverage of the grafts before suturing was performed. After a 4-7month waiting period, 199 implants were placed (105 in the study group, 94 in the control group) and 3-4months afterward prosthetic rehabilitation was carried out. The mean follow-up after the start of prosthetic loading was 23.9months (range: 12-48months). The incidence of soft tissue dehiscences was 5,7% in the study group and 16% in the control group. The mean graft resorption before implant placement was 0.12mm (SD±0.32) in the study group and 0.98mm (SD±2.79) in the control group. The mean peri-implant bone resorption at the end of the follow-up period was 0.21mm (SD±0.48) in the study group and 0.43mm (SD±0.83) in the control group. The survival rate of implants was 99.1% in the study group and 100% in the control group, while success rate was 96.2% in the study group and 93.6% in the control group. The use of pericranium as an autogenous membrane for the coverage of onlay bone grafts seems to reduce the risk of soft tissue dehiscences after the reconstruction of atrophic edentulous ridges to reduce peri-implant bone resorption over time, while it seems to have no significant effect in reducing bone resorption in the reconstructed areas before implant placement.

A Comparison between Endodontics and Implantology: An 8‐Year Retrospective Study

The aim of this study was to compare endodontic and implant treatments and to evaluate their predictability over an 8-year period on the basis of an analysis of survival data and a retrospective clinical study. A group of 40 partially edentulous patients were selected for this study. Their teeth had been endodontically treated and rehabilitated using gold alloy and ceramic restorations. In these patients, 65 osseointegrated implants were restored with single gold alloy-ceramic crowns and monitored on a yearly basis for 8 years with standardized periapical radiographs, using a polivynilsiloxane occlusal key as a positioner. A total of nine patients who did not attend the yearly follow-up were excluded from the study. The Melloning and Triplett criteria were used to evaluate the clinical results obtained in the implant sites. The clinical results of the 56 endodontically treated teeth, restored with the fixed prosthesis of 40 patients, were analyzed according to probing depth as well as an assessment of the correct apical and coronal seals. The survival rate was calculated using the Kaplan-Meier method and the statistical significance was calculated using the chi-square test. During the follow-up of the endodontically treated elements, seven failures were detected (83.34%) and the success rate of implants inserted in the same patients was equal to 80.8%, with nine implants lost in 8 years. The survival analysis of the elements treated with both therapies was not statistically significant (p = .757) and the confidence interval was between 0.2455 and 2.777. In view of the superimposable results between the two therapies, it should be noted that the endodontically treated teeth could be interested by different pathologies while the restoration of the atrophic edentulous ridge with an implant support is predictable when patients comply with correct oral hygiene and when the occlusal loads are axially distributed in implant-protected occlusion.

903 高度な顎堤吸収を持つ下顎両側性遊離端義歯・支台歯とその周辺組織のインプラント支持による荷重伝達特性(J04-1 臨床医歯学における非・低侵襲計測技術の展開(1) 歯科・整形外科における計測および生体シミュレーション,ジョイントセッション,21世紀地球環境革命の機械工学:人・マイクロナノ・エネルギー・環境)

The purpose of this study was to photoelastically compare the load transfer characteristics of a distal extension RPD with implant assisted support in the posterior of a mandible with an atrophic edentulous ridge. The model included the anterior teeth and the first premolars bilaterally. Threaded implants, 3.75mm diameter 7mm length, were embedded 20mm distal to the first premolars on the posterior edentulous ridges. I-bar partial dentures with mesial rests were fabricated and physiologically adjusted to the models. The implant support conditions tested were healing abutments and 3mm ball attachments. Simulated vertical and lateral occlusal loads were applied at the first molar position and the stress developed in the abutment teeth were monitored photoelastically. Posterior implants with both healing abutment and ball attachments in the posterior of a mandible tended to assist support of a distal extension RPD and produce only low level stresses in the supporting atrophic edentulous ridge.