Initial Ridge Width Research Articles

Horizontal ridge augmentation through ridge expansion via osseodensification, guided bone regeneration and ridge‑split: Systematic review and meta‑analysis of clinical trials.

The aim of the present systematic review was to compare three ridge augmentation procedures in order to assist clinicians in finding the ideal surgical method relative to the horizontal bone gain needed and the width of the alveolar ridge available. An electronic and hand literature search was performed in the online databases PubMed-Medline, Cochrane Central Register of Controlled Trials, EMBASE, Cochrane Oral Health Group Trials Register and Web of Science, and various specialized journals, between January 2017 and December 2022. The included studies were evaluated using the Methodological Index for Non-randomized Studies score and Cochrane's RoB tool. The primary variable studied in the meta-analysis was the final bone gain. The implant survival rate and initial ridge width were the secondary variables. Then four studies on ridge expansion via osseodensification (OD), seven on guided bone regeneration (GBR) and seven on the ridge-split technique (RS) were included in the review; 17 out of 18 were selected for meta-analysis. The mean horizontal bone gain for OD was 2.151 mm [1.327-2.975 mm; 95% confidence interval (CI)], for GBR was 4.036 mm (3.351-4.772 mm 95%CI) and for RS was 3.661 mm (2.991-4.399 mm 95%CI). The results were statistically significant (P=0.002). GBR reported the most bone gain horizontally, followed closely by RS and then OD. OD is a recent technique that should be taken into account when discussing the protocols of horizontally atrophied ridge rehabilitation.

Ridge Expansion in Two Surgical Stages Using the Transitional Implant Technique. Case Series with 8-Year Follow-Up

Extremely wide bony ridges require surgical procedures in order to insert dental implants. When less than 3 mm is present, different procedures are available, with ridge splitting being one of the most commonly used. The main limitation of this procedure is the angulation of the inserted implant. The two-stage split with transitional implants was created to overcome this drawback and achieve greater bone volume in the intervention area. This case series shows patients treated with this novel procedure. Material and Method: We retrospectively analysed patients who had undergone two-stage ridge expansion (using transitional implants) with at least 9 years of follow-up from the loading of the definitive implant, both in the maxilla and mandible. Data collection was performed by two independent examiners (different from those performing the prosthetic or surgical phase). All data were entered into a database which was managed by computer for the subsequent statistical analysis. The implant was the unit of analysis for descriptive statistics in terms of location, implant dimensions, and radiographic measurements. The primary variable was implant survival and as secondary variables mesial and distal bone loss and final bone crest width achieved after transitional implant integration, before replacement, were recorded. Results: Thirteen patients were recruited, and 30 transitional implants were inserted for width expansion in two surgical stages. These transitional implants were subsequently replaced by definitive implants at 5 months in the maxilla and at 3 months in the mandible. The mean initial ridge width of all two-stage split sites was 2.65 mm (+/- 0.63), range 1.32 to 3.70 mm. After placement of the transitional implants and bone healing, the final mean width of the specimen was 7.60 mm (+/- 0.26), range 4.31 to 12.20 mm. The mean mesial bone loss after loading of the final implant was 0.80 mm (+/- 0.26) and the mean distal bone loss was 0.85 mm (+/- 0.25). Conclusion: The two-stage split technique to achieve a gain in width of the residual bone crest is minimally invasive, predictable and the implants placed in the final (definitive) stage have a high survival rate, as we have seen in the present study with 9 years of follow-up.

Implant Site Development Using Titanium Mesh in the Maxilla: A Retrospective Study of 58 Mesh Procedures in 48 Patients.

This article presents a retrospective case series of implant site development using titanium mesh (Ti-mesh) in the maxilla. A total of 58 mesh procedures in combination with several different bone grafts (allograft, cellular allograft, and bovine xenograft) and biologics (including recombinant human platelet-derived growth factor, autogenous platelet-rich growth factor, and recombinant human bone morphogenetic protein-2) were performed in 48 patients. Ti-mesh guided bone regeneration procedures were performed 2 to 3 months after extraction of nonrestorable/hopeless teeth, and the implants were placed 6 to 8 months postaugmentation. The mean initial ridge width was 2.0 ± 1.0 mm, and the mean horizontal gain after Ti-mesh procedures was 4.7 ± 1.6 mm. The ridge width was first measured on the cross-sectional presurgical CBCT image and then confirmed clinically during surgical procedures. No statistical difference in the horizontal gain was found among different combinations of bone grafts and biomaterials. Ti-mesh exposure occurred 22% of the time. The middle-aged adults (odds ratio [OR] = 8.59; P = .046) and older adults (OR = 16.66; P = .02) had significantly higher chances of mesh exposure compared to young adults. While all implants were successfully placed, about 56% of the implants had < 2 mm of bone to the facial aspect of the osteotomy and received additional contour augmentation when placed in a prosthetically appropriate position for a screw-retained restoration. This study demonstrates that although Ti-mesh procedures result in significant bone regeneration in narrow alveolar ridges to predictably allow implant placement, the age-related mesh exposure rate and frequency of need for additional contour grafting should be discussed with patients.

Efficacy of the Tent-Pole Technique in Horizontal Ridge Augmentation

Objective: To evaluate the efficacy of the technique for ridge augmentation prior to implant placement. Material and Methods: Six patients with nine sites presenting an initial ridge width of smaller than 4 mm were included in this study. The tent-pole technique (combination of osteosynthesis screws measuring 1.5 mm in diameter, ABBM, and resorbable collagen membrane) was applied at defect sites. After eight months of healing time, implants were placed in the treated sites. The primary outcomes (radiographic initial ridge width, re-entry ridge width, ridge width gain) were measured by cone-beam computed tomography in reference buccopalatal cross-sections and the secondary outcomes (clinical parameters) were recorded by a digital caliper at the first and second stages. Results: After grafting, the radiographic ridge width increased by 3.02 ± 1.11 mm (1.57-4.75 mm) at 2 mm below the crest and 3.32 ± 1.70 mm (0.23-5.66 mm) at 6 mm below the crest significantly (p< 0.05). For clinical results, the mean horizontal dimension gain was 3.21 ± 1.04 mm (1.83-4.57 mm), while the mean reduction in dimension was 0.38 ± 0.33 mm. These results were statistically significant (p<0.05). Uneventful healing and no infections or membrane exposure were recorded at all sites during the study process. Three of nine (33.33%) defect sites required additional bone grafting. Conclusion: The tent-pole technique is an effective method for increasing the horizontal ridge dimension, minimizing postoperative complications, and facilitating subsequent implant placement.

Buccal bone thickness adjacent to virtual dental implants following guided bone regeneration.

Crestal bone thickness is a critical determinant of peri-implant tissue stability. This retrospective observational study sought to quantify the buccal bone thickness achieved adjacent to virtual dental implants following guided bone regeneration (GBR) surgery and evaluate the influence of patient- and procedure-related variables on buccal bone thickness. Cone-beam computed tomography (CBCT) images acquired from patients who had undergone GBR surgery between July 1, 2012, and November 7, 2016, were used for this analysis. In all cases, the GBR procedure involved a dense polytetrafluoroethylene (dPTFE) barrier membrane and a mineralized cortical particulate freeze-dried bone allograft (FDBA). Eighty-four virtual dental implants were placed at planned locations using CBCT images from 84 patients, and the adjacent buccal bone thickness was measured at each site. The effects of sex, age, estimated baseline ridge width, number of missing teeth in site, site type (tooth-bounded versus terminal position in arch), dental arch (mandibular or maxillary), arch location (anterior or posterior), smoking status, titanium reinforcement in the membrane, membrane fixation, and tenting screw use were assessed. The mean post-GBR buccal bone thickness adjacent to virtual dental implants was 2.24 ± 1.01 mm. Fifty-nine of 84 virtual implants (70%) exhibited buccal bone thickness>1.9 mm. GBR sites using membrane fixation produced significantly greater virtual implant buccal bone thickness than those without membrane fixation (2.31 ± 0.96 versus 1.15 ± 1.25 mm, P=0.012). Virtual implant buccal bone thickness also exhibited moderate correlation with estimated initial ridge width (r=0.43, P<0.0001). The alveolar ridge at 81 virtual implant sites (96%) was classified as good or satisfactory, meaning dental implants were actually placed at these sites, with or without additional grafting at implant placement. Observations in this study suggest GBR procedures using dPTFE membranes and FDBA result in favorable ridge dimensions for dental implant placement in most cases. However, additional augmentation at implant surgery may be necessary at ≈ 30% of sites, if buccal bone thickness>1.9 mm is intended.

Lateral Ridge Splitting (Expansion) With Immediate Placement of Endosseous Dental Implant Using Piezoelectric Device: A New Treatment Protocol.

Many treatment modalities have been introduced for correction of deficient alveolar ridge width. Bone expansion through the ridge split procedure is one of them. This technique was initiated in order to overcome many problems that usually associated with grafting procedures. The present study evaluated the effectiveness of piezoelectric device in performing ridge split using single-stage approach and assessed the outcomes during a period of about 4 months after surgery. A total of 23 patients aged in range between 18 and 60 years underwent ridge split procedure with immediate insertion of dental implants. A panoramic radiograph was obtained before surgery. The gained bone was measured and surgical complications were recorded. Implants stability was measured using Osstell device. Postoperative clinical complications were assessed. After a healing period of 16 weeks, all the implants were uncovered and evaluated regarding clinical, radiographic, and resonance frequency analysis findings. The totally implemented ridge split procedures were 26 cases including 57 implants inserted immediately at the time of surgery. The initial ridge width varied between 1 and 3.5 mm while the final width ranged from 5.5 to 8 mm. The minimum bone gain was 2.5 mm and the maximum value reached up to 7 mm. Few and insignificant clinical complications were recorded during the whole study. The survival rate was 100%. The study results indicated that piezoelectric ridge splitting technique is an effective, safe, and minimally invasive procedure. This technique has showed to be very successful in reducing the overall treatment period.

Ridge Width Gain With Screw Spreaders

The aim of this cadaver study was to evaluate the amount of ridge expansion with screw spreaders. Eleven edentulous maxillae providing 20 eligible sites were used. Ridges with initial width of 3 to 6 mm were expanded using a set of 6 screw spreaders, and implants (ø3.7 × 10 mm) were subsequently placed. Ridge width at 2 mm apical to the crest was measured at the baseline, after expansion, and implant placement. Buccal plate thickness and incidence of buccal dehiscence after implant placement were measured. The mean initial ridge width was 3.97 ± 0.82 mm. After the expansion, the mean ridge width increased to 4.76 ± 0.77 mm (Δ = 0.79 mm). Majority of sites (7/9 sites) with an initial ridge width of <4 mm had a buccal dehiscence after implant placement. A buccal plate thickness of ≥1 mm was consistently present in cases with an initial ridge width of ≥4.5 mm after implant placement. The screw spreaders had a modest effect on ridge expansion. Their use might be limited because additional bone augmentation might be required to prevent or correct the bony dehiscence encountered in ridges <4.5 mm wide. Therefore, using this particular instrument kit for horizontal ridge augmentation is only indicated in specific cases.

Modified Edentulous Ridge Expansion Technique and Immediate Implant Placement: A 3-Year Follow-Up

Restoration of the edentulous alveolar ridge with implants often requires the ridge width to be augmented to allow its placement. The aim of this study was to evaluate the split-crest technique, with subepithelial connective tissue graft used as biological barrier, in patients with narrow ridges, focusing on the status of soft and hard tissues and on implant success rate, at 36 months after implant loading. Thirteen patients (6 males and 7 females), ages 32-68 years (mean 49.4 years) with an atrophic maxillary jaw underwent modified edentulous ridge expansion technique for implant placement. A total of 33 Laser-Lok tapered internal implant, were placed in the maxilla. The following parameters were evaluated: (1) initial ridge width (time t0); (2) ridge width at the time of abutment connection (time t1); four months after implants placement, healing abutments were connected and the prosthetic rehabilitation was initiated, and all patients were evaluated clinically and radiographically with periapical radiograph at intervals of 3-6 months for the first year and annually thereafter for 3 years. The ridge width was measured with a cone beam computed tomography. The initial ridge width ranged from 3.5 mm to 7 mm (mean: 4.67 mm), while at the end of the expansion procedure the width ranged from 6.3 mm to 11.0 mm (mean: 8.2 mm). The width gain of the edentulous ridge ranged from 1.45-4.9 mm (mean: 3.5 mm). Two implants became exposed 1 month after surgery. One implant was lost before loading (3%). The diameter of failed implant was 5.8 mm and length was 10.5 mm. The remaining 32 implants were stable and free of complications at the end of the study. Thus, the implant survival rate was 97%. Because no implant failed after loading, the cumulative survival rate of loaded implants was 100%. The minimally invasive regenerative technique presented here avoids the use of bone graft, secondary surgery for soft tissue augmentation, and mechanical expansion devices. However, the follow-up period for outcome evaluation and exiguous patient's number in this series was limited.

Determinants of alveolar ridge preservation differ by anatomic location

To investigate and compare outcomes following alveolar ridge preservation (ARP) in posterior maxilla and mandible. Twenty-four patients (54±3years) with single posterior tooth extraction were included. ARP was performed with freeze-dried bone allograft and collagen membrane. Clinical parameters were recorded at extraction and re-entry. Harvested bone cores were analysed by microcomputed tomography (micro-CT), histomorphometry and immunohistochemistry. In both jaws, ARP prevented ridge height loss, but ridge width was significantly reduced by approximately 2.5mm. Healing time, initial clinical attachment loss and amount of keratinized tissue at extraction site were identified as determinants of ridge height outcome. Buccal plate thickness and tooth root length were identified as determinants of ridge width outcome. In addition, initial ridge width was positively correlated with ridge width loss. Micro-CT revealed greater mineralization per unit volume in new bone compared with existing bone in mandible (p<0.001). Distributions of residual graft, new cellular bone and immature tissue were similar in both jaws. Within the limitations of this study, the results indicate that in different anatomic locations different factors may determine ARP outcomes. Further studies are needed to better understand determinants of ARP outcomes.

Evaluation of horizontal ridge augmentation using beta tricalcium phosphate and demineralized bone matrix: A comparative study

Objectives: To evaluate the effectiveness of beta tricalcium phosphate (β-TCP) alone compared to β-TCP and Demineralized Bone Matrix (DBM) in regenerating localized horizontal maxillary alveolar ridge deficiencies prior to implant placement. Study Design: The study included 20 patients with horizontal maxillary ridge deficiencies limited to one or more neighbouring teeth and initial ridge width of ≤ 5mmm. Patients were divided equally into two equal groups. Ridge augmentation was performed using Guided Bone Regeneration (GBR) principals. In group I GBR was performed using β-TCP only, while in group II both β-TCP and DBM were used. Following a 6 months healing period, bone cores from both groups were retrieved and implants were inserted. Specimens were examined histologically to calculate percentage of mineralized bone. Apical and crestal changes in ridge dimensions were calculated by digital subtraction using Cone Beam Computed Tomography (CBCT) immediately after graft placement and six months later. Results: There was a statistically significant difference between the mean area percentage of mineralized bone between both groups where it was 40.1 % (range: 27.76-% 66.29 %) for group I and 68.96 % (range: 60.07 % - 87.33 %) for group II. Radiograpically, the mean ridge width in group I increased crestally to 4.66 mm (range:3.5-5mm) and apically to 6.12 mm (range: 4.1-6.7 mm). In group II the mean ridge width increased crestally to 5.2 mm (range 4.9-5.4mm) and apically to 6.9 mm (range 6.0-7.8 mm). Group II showed more bone gain with a mean of 1.37 mm crestally and 2.44 mm apically. This difference however was not statistically significant Conclusion: Within the limitations of this study the combination of DBM and β-TCP can be used effectively in cases exhibiting minimal alveolar ridge defects. Key words:Guided bone regeneration, equine bone, alloplast, bone graft.

Split‐crest and immediate implant placement with ultra‐sonic bone surgery: a 3‐year life‐table analysis with 230 treated sites

Ultra-sonic bone surgery (USBS) has been recently introduced as a novel osteotomic technique. This clinical study reports on the application of this new technique to perform ridge-split procedures. Over a period of 3.5 years, 57 patients underwent a split-crest procedure with the aim to place 230 implants, 78 in the mandible and 152 in the maxilla, in order to rehabilitate nine full arches, three hemi-arcades, 43 partial bridges and 24 single crowns. The initial ridge width varied between 1.5 and 5 mm, average was 3.2 mm. The final width of the ridge ranged from 4 to 9 mm, average was 6 mm. The split length varied between 4.5 and 40 mm, average was 15 mm. Inserted implants were 3.25-5 mm in diameter however most of them (82.4%) were standard implants of 3.75 mm; implant length was classically 10-13 mm. Two hundred and twenty-eight (99.1%) out of the 230 planned implants were placed, the two non-suitable sites were in the maxilla. In the mandible, the ridge augmentation procedure was drastically eased by performing a basal longitudinal discharge notch. At second stage surgery, eight implants failed to osseointegrate; the success rate for the placed implants was 96.5%. All implants have been loaded for at least 2 months and no implant was lost after loading. One hundred and eighty-one and 77 implants have been loaded for at least 6 and 12 months, respectively. The 3-year life-table analysis of loaded implants showed a cumulative survival rate of 100%. The split-crest procedure performed with USBS showed to be safe and comfortable.

High-performance 1.3-μm InAsP strained-layer quantum-well ACIS (Al-oxide confined inner stripe) lasers

We have demonstrated high-performance 1.3-/spl mu/m InAsP strained-layer quantum-well lasers with Al-oxide confined inner stripe (ACIS) structure. The oxidized layers are consisted of strain-compensated AlAs-InP-AlInAs (6 nm/2 ML/3 nm) superlattice (SAS) layers and grown on InP substrate using gas-source molecular beam epitaxy (GS-MBE). For the structural optimization of the ACIS laser, the dependence of quantum efficiency, threshold current and lateral mode characteristics on the initial ridge width and the current aperture width have been investigated. A very low-threshold current of 2.0 mA, a high differential quantum efficiency of 67% and stable single lateral mode operation of over 40 mW were obtained for the optimized ACIS lasers. The excellent characteristics obtained in the ACIS lasers are attributed to both the current and the optical confinements by the Al-oxide layer. In addition, we confirmed high uniformity of the threshold current and the oxidized width. This device is very promising candidate for low-cost access networks and optical interconnects.