Bone Gain Research Articles

Sub-antral volumetric variation after a modified trephine sinus elevation approach: An 8-month prospective study

Aim To overcome vertical deficiency of atrophic posterior maxilla, sinus floor elevation has been used for several decades either through a transcrestal or a lateral approach. In 1999, Fugazzotto et al. described a modified trephine/osteotome technique for sinus floor augmentation at the time of maxillary molar extraction without implant placement. A trephine was used to create a bone core in the middle of the extraction site and was gently malleted apically. In 2002, Fugazzotto et al. used the same principle to place dental implants in healed maxillary molars sites with limited residual height (RH). This procedure demonstrated a 98.3% implant survival rate at 4 years but lacked radiographic information. The aim of the present study was to assess the efficacy of the modified trephine/osteotome sinus elevation with implant placement, using a clinical and a radiographic cone beam evaluation. Materials and methods Twenty-one implants were placed in premolar and molar sites with 3≤ RH ≤6mm using the modified trephine/osteotome sinus elevation approach and were evaluated clinically and radiographically at baseline (T1), 3 (T3) and 8 (T8) months. Results Implant survival was 100% at 8 months. Sub-antral volumetric bone gain between T1 and T8 was 20.34%. Linear bone gain was 2.1 ± 1.1 mm buccally; 2.0 ± 1.4 mm palatally; 2.5 ± 1.6 mm mesially; and 1.5 ± 1.5 mm distally. Mean linear bone gain was 2.0±1.1 mm calculated on the CBCT. Implant stability quotient (ISQ) at T1 was 66.378±7.931, and 67.921±14.369 at T3 without a statistically significant difference between the two measurements. Residual height was positively correlated to vestibular, palatal, and mesial bone gain. Signs of Schneiderian membrane tearing were noticeable in one case. Conclusion This study demonstrated that sufficient subantral bone formation can be obtained with the modified trephine/osteotome technique with high implant survival rate and low post-operative morbidity.

Maxillary vertical alveolar ridge augmentation using computer-guided sandwich osteotomy technique with simultaneous implant placement versus conventional technique: A pilot study.

Sandwich osteotomy technique (Inlay bone grafting) is considered as a highly reliable procedure for vertical bone augmentation in the maxillary anterior esthetic zone. The aim of this study was to compare vertical bone gain and palatal tipping using computer-guided inlay technique versus the conventional technique. This was a randomized clinical trial including 12 patients who were randomly divided into two groups: sandwich osteotomy with simultaneous implant placement at the anterior maxillary esthetic zone (six patients) using patient-specific guides (PSGs) in the study group versus conventional technique (six patients). In the control group, free-hand sandwich osteotomy was done, while in the study group all the procedures were performed with two sequential PSGs with cutting slits, guiding holes, and implant sleeves. Radiographic assessment included measurements of linear changes in the vertical dimensions of the labial plate of bone and palatal tipping on cross-sectional cuts of cone-beam computed tomography using special software. All the procedures were uneventful except one case of the study group showed a cracked bony segment that did not affect the final outcome. Radiographic results showed comparable bone gain in both groups with no statistical significance difference (study group 4.4 mm, control group 3.9 mm). To the contrary, the computer-guided approach significantly reduced the palatal tipping to 0.4 mm compared to 2.1 mm in the conventional group, and there was a statistically significant difference between the two groups (p-value <0.001). Sandwich osteotomy using PSGs appears to be efficient and showed promising results regarding improving the palatal tipping compared to the free-hand technique.

Outcomes of Bifocal Transport Distraction Osteogenesis for Repairing Complicated Unilateral Alveolar Cleft

This study aimed to assess the outcomes of bifocal transport distraction osteogenesis (BTDO) for closure of a wide or previously failed unilateral alveolar cleft. Patient in this study had a large alveolar cleft that had not healed with bone grafts. Bone-borne distraction was used under general anesthesia. Intraoperative complications as bleeding and trauma to neighboring teeth were documented. Postoperative complications as wound dehiscence, paresthesia, infection, and bleeding were recorded. Complications including changes in bone segment movement, activation force loss, and occlusal interferences were observed during the activation phase. During the consolidation phase, problems including gingival recession, pulpal vitality, and cosmetic concerns were evaluated. Postoperative, periapical, occlusal, and orthopantomograms were used to evaluate bone gain and bone generation in the distracted area. Ten patients (6 males and 4 females) with unilateral alveolar cleft were included, with mean age of 9.5 ± 2.5 years. Average cleft width was 12.25 ± 2.54 mm. There was no intraoperative or postoperative bleeding. Only 1 patient had a wound dehiscence (10%). All patients had mild postoperative pain and edema in upper lip. Only 1 patient complained of numbness in infraorbital nerve's innervated region. Radiographs revealed bone formation in cleft area and bone healing in distracted chamber. Bifocal transport distraction osteogenesis improves success rate of an alveolar cleft treatment especially a wide or previously failed one. This technique associated with minimal complications when careful planning and cooperation from a patient are combined. It can be recommended when other modalities for alveolar cleft are failed. Patients also tolerate the device well.

The influence of laser-microgrooved implant and abutment surfaces on mean crestal bone levels and peri-implant soft tissue healing: a 3-year longitudinal randomized controlled clinical trial

PurposeThe study aimed to compare clinical and radiographic parameters of peri-implant site of laser-microgrooved implants with either laser-microgrooved or regular machined prosthetic abutment post 3 years of early loading.MethodTwenty edentulous sites of systemically and periodontally healthy individuals were allocated into two groups in this prospective, two-armed, randomized double-blinded clinical trial in 1:1 ratio, wherein each site received laser-microgrooved implants with either laser-microgrooved or machined prosthetic abutments. Outcome measures included full-mouth plaque (FMPS%) and bleeding score (FMBS%), site-specific plaque (SPS%) and bleeding score (SBS%), peri-implant sulcus depth (PISD mm), and mean crestal bone loss (MCBL mm) evaluated at baseline (6 weeks), 1 and 3 years post-early loading. Mean and standard deviation of all parameters were estimated, between groups and at different time points using independent and paired t-test, respectively, Normality was checked using Kolmogorov–Smirnov test and Shapiro–Wilk test, P value ≤ 0.05 was considered as statistically significant.ResultsThree-year follow-up of test group showed statistically significant reduction in SPS, SBS, PISD (P value ≤ 0.001). The MCBL reduced from 1.93 mm to 0.61 mm (P value ≤ 0.001); in other words, a bone gain of 0.15 mm was obtained in the test group.ConclusionWithin the limitations of the present study, laser-microgrooved implants loaded with laser-microgrooved prosthetic abutments showed superior results clinically and radiographically when compared to loading with machined abutments.

Retrospective study on the merits of bone grafts and the influence of implant protrusion length after osteotome sinus elevation surgery.

This study aims to evaluate the endo-sinus bone remodeling of dental implants placed via osteotome sinus floor elevation (OSFE) after 6 months and using different implant protrusion lengths and bone grafts through cone beam computed tomography (CBCT). Ninety-six patients with 124 implants were included and assigned into four groups. Group 1: implant protrusion length<4 mm with bone graft; group 2: implant protrusion length>4 mm with bone graft; group 3: implant protrusion length<4 mm without bone graft; group 4: implant protrusion length>4 mm without bone graft. Apical bone gain (ABG), cortical bone gain (CBG), bone density gain (BDG), and marginal bone loss (MBL) were observed and analyzed at baseline and 6 months after implant surgery. The CBG in grafted groups 1 and 2 was higher than that in non-grafted groups. The ABG and BDG were higher in non-grafted groups 3 and 4 than in grafted groups, and the levels in group 3 were higher than those in group 4. The CBG in grafted group 2 was higher than that in group 1. No significant difference was observed in MBL analysis. The BDG of IPL<4 mm implants was higher than IPL>4 mm implant when bone grafts were not applied. No relevance was observed between IPL and CBG. Bone grafts can accelerate endo-sinus bone remodeling by increasing CBG and dissipating the influence of IPL on BDG.

“HORIZONTAL ALVEOLAR RIDGE AUGMENTATION WITH AUTOGENOUS BLOCK BONE GRAFT A CONE BEAM COMPUTED TOMOGRAPHY EVALUATION CASE SERIES”

Objective: The aim of the present study was to evaluate horizontal alveolar ridge augmentation using autogenous block grafts harvested from mandibular symphysis without barrier membrane in severe maxillary anterior ridge defects. Materials and methods: Six healthy patients with horizontal defects of the maxillary alveolar ridges were selected for alveolar ridge augmentation (class IV atrophy according to Benic and Hammerle classification). These defects were treated by autogenous block onlay grafts harvested from mandibular symphysis protected by anorganic bovine bone particles only. bone width was assessed preoperative, immediately post-operative and after 6 months at re‐entry by cone beam computed tomography. Result: All block grafts sites provided sufficient ridge width for proper implant placement. Mean bone gain was 3.9mm. No soft tissue dehiscence occurred in any of the cases. Conclusion: A combination of autogenous block graft obtained from the symphysis, combined with particulates xenograft alone without barrier membrane is a predictable and successful technique for augmenting maxillary horizontal ridge deficiency.

Ridge Augmentation using Autologous Concentrated Growth Factors (CGF) Enriched Bone Graft Matrix (sticky bone) versus Guided Bone Regeneration using Native Collagen Membrane in Horizontally Deficient Maxilla

Aim: The aim of the study is to introduce an easy and predictable method for horizontal bone augmentation in maxillary bone ridge using autologous concentrated growth factors (CGF) enriched bone graft matrix (sticky bone) versus guided bone regeneration using native collagen membrane Methodology: A total of 28 patients presenting with Cawood Class IV ridge classification (2-4mm residual alveolar width) were included in the study. 14 patients received horizontal augmentation using sticky bone prepared from a 1:1 mixture of autogenous and anorganic bovine bone minerals covered by a concentrated growth factors (CGF) membrane. The other 14 patients received horizontal augmentation using same mix covered by a native collagen membrane (sausage technique). CBCT scans were taken immediately postoperative and after 6 months to measure the horizontal bone gain in both groups. Results: For native collagen group, the median horizontal gain measured at 2, 5 and 10 mm from the alveolar crest was 2.55 with range (1.43 ,4.34) mm, 2.61 with range (0.02 ,4.71) mm and 1.15 with range (-2.88 ,4.89) mm, respectively. While for CGF group, the median horizontal gain measured at 2, 5 and 10 mm from the alveolar crest was 1.54 with range (-0,97, 2.93) mm, 2.8with range (-2.01, 5.27) mm, 2.97 with range (-1.32, 5.4) mm, respectively. Conclusion: Within the limitations of the study, horizontal ridge augmentation using sticky bone covered by CGFmembrane is a simple technique with unpredictable results compared to guided bone regeneration using native collagen membrane.

Fixation screw minimizes bone graft loss following autogenous lateral block graft augmentation: An experimental in vivo study

PurposeAssess the role of tenting screws in the remodeling processes of autogenous bone blocks used for mandibular lateral augmentation in rabbits. MethodsEighteen rabbits, approximately 3.5–4.0 kg of weight and 4–5 months of age, were included in this study. One lateral side of the angle of the mandible was augmented with block autografts. Animals were euthanized after 7, 20 and 60 days of healing, respectively. Biopsies were taken for each period and specimens underwent microtomographic scanning. The total volume (TV, mm3), bone volume (BV: residual graft plus new bone, mm3), periimplant bone volume (PIBV), bone implant contact (BIC) along the screw and linear bone gain at five vertical points symmetrically dispersed from the fixation screw in the midline were measured. ANOVA and the t-test were performed. ResultsThe total volume (TV) of autografts decreased between 7 and 60 days from 258.13±15.3 mm3 to 107.2 ± 17.5 mm3 (p < 0.05). Contraction rates of 58.5% were observed. BV was 52.8 ± 7.7 mm3, 27.2 ± 11.1 mm3, and 33.1 ± 2.8 mm3 after 7, 20, and 60 days of healing, respectively. PIBV and BIC remained unchanged along time demonstrating no contraction around the screw. Total linear bone gain demonstrated a total of 18% linear contraction after 60 days. Point 1, demonstrated no changes along time representing no resorption along time. Points 2 and 4 demonstrate a minimum linear contraction (10–15%) with borderline significance. Resembling the total results, contraction starts after 20 days. Points 3 and 5 demonstrate a statistically significant contraction (p<0.05) of 35–40% starting at 20 days. ConclusionTenting screws may reduce bone resorption symmetrically in a model of lateral block augmentation.

Lateral augmentation of the posterior edentulous mandible: A retrospective single arm comparison of ridge split, block bone grafts and guided bone regeneration

AbstractBackgroundA deficient hard and soft tissue at the surgical site is a definitive challenge for dental implant placement. Commonly used procedures for augmentation include block bone grafts, guided bone regeneration, distraction, ridge expansion, ridge split, sandwich osteotomy, etc. The current study evaluates three techniques employed for horizontal augmentation of the mandible.MethodsA retrospective chart review was conducted for patients reconstructed with either block bone (A), guided bone regeneration (B), or ridge split (C) for lateral augmentation of posterior mandible. The primary outcome variables assessed were immediate postoperative bone width and bone width after 4 months, bone gain and resorption. Complications were evaluated as secondary outcomes. ANOVA and post hoc turkey tests were used for statistical analysis. A p‐value of &lt;0.05 was considered as statistically significant.ResultsA total of 250 patient records were included in the study. Group C had a mean bone gain of 5.8649 ± 0.6520 mm statistically significant from others. Resorption was maximum in Group B 1.1612 ± 0.2821 mm. Iliac crest graft gave a mean 5.7285 ± 0.1823 mm bone gain. Overall no difference in bone gain between particulate or block interposition.DiscussionGrafts from intraoral sites are comparable in terms of resorption. ARS considerably provides better augmentation compared to GBR and onlays.ConclusionRidge split followed by onlay block bone grafting provides the best outcomes. Ramus and symphysis grafts are comparable. Iliac grafts are still the best for significant augmentations. Guided bone regeneration suffers maximum resorption.

Short Dental Implants on Rehabilitation of Atrophic Maxillary Ridge Utilizing Digital Planning

This is a clinical case of a healthy man with a missing upper right lateral incisor (#12) and canine (#13) who requested for a permanent prosthetic replacement due to a history of trauma. An orthodontic alignment was performed to idealise the spaces in the upper and lower arches. A horizontal guided bone regeneration (GBR) was then performed on the residual ridge on #12 and #13 using the xenograft [Cerabone ®, Botiss gmbh, Berlin, Germany] and resorbable collagen membrane (Lyoplant®). After 12 months, the radiographic analysis showed apparent bone-fill with an adequate horizontal bone gain which was further analysed using a specialized software for digital implant planning [R2GATE v1.1.1; Megagen, Daegu, Korea]. Two short dental implants (7.0 mm) were incorporated as part of the overall treatment plan. In this case, the utilization of the short implants on a previously augmented ridge with the aid of a digital implant planning showed excellent an clinical outcome.

Guided bone regeneration in the anterior maxilla after tooth extraction and implant removal with sticky bone and L-PRF membrane in two surgical approaches

The main requirement for the insertion of dental implants is a good bone and gum condition and guided bone regeneration (GBR) combines grafts and membranes to increase such parameters in tissue deficiencies and thus achieve treatment success. This clinical case reports the oral rehabilitation of the anterosuperior area by the association of bone graft, autologous membrane and implantodontic therapy. Female patient, 45 years old, normosystemic, reported aesthetic complaint and implant mobility in the maxilla. Upon clinical and radiographic examination, an implant was diagnosed in the region of tooth 11 with unfavorable esthetics, mobility, inadequate prosthesis and bone loss, and tooth 22 with suppuration, fracture line and periapical radiolucency. The treatment consisted of removal of the implant and tooth 22, with immediate GBR using filling with Bio-Oss® and liquid leukocyte- and platelet-rich fibrin (L-PRF) and coating with L-PRF membrane. After 7 months, the second GBR was performed with the installation of 2 dental implants. After 6 months, healers were placed and 20 days after the adaptation of the provisional implant-supported single prostheses. There was a good gain in thickness and mucogingival limit, bone dimensions in height and thickness, and the case continues to be followed up until the final prosthesis is completed. This case suggests that sticky bone and L-PRF membrane can contribute to multiple GBR in the anterior maxillary region, favoring bone gain and osseointegration.

Efficacy of periodontal minimally invasive surgery with and without regenerative materials for treatment of intrabony defect: a randomized clinical trial.

The minimally invasive surgical technique was modified in suture (MISTms) in this study. The trial was to determine the efficacy of MISTms with and without regenerative materials for the treatment of intrabony defect and to identify factors influencing 1-year clinical attachment level (CAL) gain. Thirty-six patients with interdental intrabony defects were randomly assigned to MISTms (MISTms alone, 18) or MISTms plus deproteinized bovine bone mineral and collagen membrane (MISTms combined, 18). Wound healing was evaluated by early healing index (EHI) at 1, 2, 3, and 6weeks. Probing depth (PD), CAL, gingival recession, radiographic defect depth, and distance from the base of defect to the cementoenamel junction were recorded at baseline and 1year postoperatively. A one-year composite outcome measure based on the combination of CAL gain and post-surgery PD was evaluated. Factors influencing 1-year CAL gain were analyzed. Fifteen patients in MISTms-alone and 16 in the MISTms-combined group finished the study. The MISTms-alone group showed significantly better wound healing at 1week. CAL significantly gained in the MISTms-alone and MISTms-combined group, with 2.53 ± 1.80mm and 2.00 ± 1.38mm respectively. The radiographic bone gain was 3.00 ± 1.56mm and 3.85 ± 1.69mm respectively. However, there were no significant differences between the two groups about 1-year outcomes. Lower EHI (optimal wound healing) and more baseline CAL positively influenced 1-year CAL gain. MISTms is an effective treatment for intrabony defects. The regenerative materials do not show an additional effect on 1-year outcomes. Early wound healing and baseline CAL are factors influencing 1-year CAL gain. MISTms with and without regenerative materials are both effective treatments for intrabony defect. ClinicalTrials.gov Identifier: ChiCTR2100043272.

Effect of periodontal-orthodontic treatment of teeth with pathological tooth flaring, drifting, and elongation in patients with severe periodontitis: A systematic review with meta-analysis.

AimTo assess the beneficial and adverse effects on the dental and periodontal issues of periodontal–orthodontic treatment of teeth with pathological tooth flaring, drifting, and elongation in patients with severe periodontitis.Materials and methodsNine databases were searched in April 2020 for randomized/non‐randomized clinical studies. After duplicate study selection, data extraction, and risk‐of‐bias assessment, random‐effect meta‐analyses of mean differences (MDs) and their 95% confidence intervals (CIs) were performed, followed by subgroup/meta‐regression analyses.ResultsA total of 30 randomized and non‐randomized clinical studies including 914 patients (29.7% male; mean age 43.4 years) were identified. Orthodontic treatment of pathologically migrated teeth was associated with clinical attachment gain (−0.24 mm; seven studies), pocket probing depth reduction (−0.23 mm; seven studies), marginal bone gain (−0.36 mm; seven studies), and papilla height gain (−1.42 mm; two studies) without considerable adverse effects, while patient sex, gingival phenotype, baseline disease severity, interval between periodontal and orthodontic treatment, and orthodontic treatment duration affected the results. Greater marginal bone level gains were seen by additional circumferential fiberotomy (two studies; MD = –0.98 mm; 95% CI = –1.87 to −0.10 mm; p = .03), but the quality of evidence was low.ConclusionsLimited evidence of poor quality indicates that orthodontic treatment might be associated with small improvements of periodontal parameters, which do not seem to affect prognosis, but more research is needed.

Horizontal Ridge Augmentation: A Comparison between Khoury and Urban Technique.

Simple SummaryWith the emergence of novelty regeneration techniques in the implant dentistry field, the professional may have some queries about which one to use in their daily practice. No systematic review, to date, analyzes the horizontal gains achievable with the two main procedures for bone regeneration: the Khoury technique, which uses split blocks obtained from the patient himself, or the Urban technique, which employs membranes to contain the biomaterials. Regarding this paper, the reader will be able to decide if any of these options is adequate for the indication required.Purpose. The objective of this systematic review was to evaluate and compare the clinical efficacy of horizontal alveolar ridge augmentation techniques described by Khoury and Urban. Methods. A systematic electronic search in the MEDLINE databases, SCOPUS, WOS, and the Cochrane Central Register of Controlled Trials (CENTRAL) as well as a manual search, were conducted independently by two reviewers up to July 2021. Results. Six studies met the pre-established inclusion criteria and were included in the descriptive analysis. Due to the heterogeneity found across the included studies, meta-analysis could not be performed. Horizontal bone gain was between 3.93 ± 0.9 mm and 5.02 ± 0.8 mm with the Khoury technique and between 3.9 ± 0.9 mm and 5.68 ± 1.42 mm with the Urban technique. Similar complication rates were reported in both groups: infection (7%), in the Khoury technique, and membrane exposure (3.2–13.6%), in the Urban technique, being the most frequent events. Conclusions. Both techniques were found to be effective, in terms of clinical bone gain, for horizontal alveolar ridge gain. Nevertheless, available literature is limited, and there is a lack of comparative studies to better evaluate the results.

Adjuvant Effect of Titanium Brushes in Peri-Implant Surgical Treatment: A Systematic Review.

Background: the prognosis of peri-implant surgery can be affected by poor decontamination of the implant surface, which could be improved with the use of titanium brushes. The objectives of this systematic review were to evaluate the effectiveness of titanium brushes in the decontamination of the implant surface in terms of plaque index, probing depth, bleeding on probing and bone loss/gain; as well as its effectiveness according to the type of peri-implant bone defect. Methods: an electronic search was carried out in the PubMed, Scopus, Cochrane and Embase databases, as well as a manual search. The search strategy included four keywords: “Peri-implantitis”, “Periimplantitis”, “Implant Surface Decontamination” and “Titanium Brush”. Randomized controlled studies published in the last 10 years were included and systematic reviews, in vitro studies and animal studies were excluded. Results: 142 references were found, from which only four articles met the inclusion criteria. All of the studies included in the present review reported beneficial results in terms of probing depth, gingival index and radiographic bone loss and gain after implant surface decontamination adjuvated by titanium brushes. Conclusions: titanium rotary brushes show improvements in the evolution and prognosis of peri-implant surgery, although more long-term studies are needed to draw more solid conclusions.

Dense Polytetrafluoroethylene Membrane versus Titanium Mesh in Vertical Ridge Augmentation: Clinical and Histological Results of a Split-mouth Prospective Study

The aim of the present split-mouth prospective study was to evaluate clinically and histologically the bone regeneration obtained following preprosthetic vertical bone augmentation performed with titanium-reinforced dense polytetrafluoroethylene membrane (d-PM) compared to titanium mesh (TM). Healthy adult patients presenting with bilateral partial edentulism in the posterior mandible requiring vertical ridge augmentation for implant placement purposes were consecutively included. One side of the mandible was randomly assigned to the use of d-PM, the other to TM. The graft consisted in a mixture of autogenous bone harvested nearby the surgical site and deproteinized bovine bone mineral particles in a 1:1 ratio. On each side during bone augmentation surgery, a 2-mm diameter mini-implant was inserted for clinical and histological analyses. After a healing period of 8 months, the second surgical phase was carried out to remove the nonresorbable barriers, to evaluate clinically the vertical bone gain, and to collect a bone biopsy that included the mini-implant. During the same surgical session, dental implants were inserted in a prosthetically guided position. A total of five patients were enrolled. Eight out of 10 sites healed uneventfully. In the remaining two sites, premature exposure of the TM was observed. Mean vertical bone gain of 4.2 and 1.5 mm was achieved in d-PM and TM groups, respectively (p = 0.06). A mean mineralized tissue of 48.28 and 35.54% was observed in d-PM and TM groups, respectively (p = 0.51). The vertical bone gain, although not significantly, was higher in the d-PM group. Similar histological outcomes were noticed if exposure did not occur. In case of wound dehiscence, major resorption was observed. Both d-PM and TM can be used to augment atrophic localized ridges vertically. The outcome of bone regeneration seems to be impaired by exposure of the device. How to cite this article: Maiorana C, Fontana F, Rasia dal Polo M, et al. Dense Polytetrafluoroethylene Membrane versus Titanium Mesh in Vertical Ridge Augmentation: Clinical and Histological Results of a Split-mouth Prospective Study. J Contemp Dent Pract 2021;22(5):465-472.

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.

Horizontal Bone Augmentation in the Posterior Atrophic Mandible and Dental Implant Stability Using the Tenting Screw Technique.

The aim of this study was to analyze horizontal bone augmentation using the tenting screw technique in the posterior mandible. Included subjects had a 3-mm bone width and 9-mm bone height, measured by CBCT. After the surgical approach, two to four screws were inserted, leaving 4 mm of extraosseous space; reconstruction was achieved using allogeneic biomaterial and leukocyte- and platelet-rich fibrin together with an absorbable membrane. After 4 months, a new CBCT scan was obtained to compare the bone gain and implant placement. Early and secondary stability were measured by the implant stability quotient (ISQ); prosthetic load was performed 16 weeks later. Student t test was used to compare bone gains and implant stability, with significance set at P < .05. Fourteen subjects and 27 surgical sites initially exhibited a mean bone width of 2.95 ± 0.75 mm. Four months after augmentation, the bone width was 7.15 ± 1.87 mm, confirming a significant bone gain (4.2 ± 1.26 mm). Twenty-seven implants were placed with a minimum insertion torque of 35 Ncm; the primary stability was 69.3 ± 7.16 ISQ, and the secondary stability was 75.9 ± 3.29 ISQ (P > .05). It may be concluded that the tenting screw technique is predictable in terms of bone gain and that it facilitates implant stability.

Microscope-Assisted Maxillary Sinus Augmentation: A Case Series.

Minimally invasive microsurgery performed using an operating microscope (OM) has shown accelerated and improved wound healing for periodontal plastic and regenerative procedures. This case series aims to demonstrate the potential usefulness of OM for maxillary sinus augmentation in a private practice setting. Twelve vertical sinus augmentations (VSAs) and 8 lateral sinus augmentations (LSAs) were performed with the assistance of OM. Flap reflection, osteotomy, sinus membrane elevation, membrane integrity evaluation, implant placement (if indicated), and wound approximation with sutures were performed under OM. After a minimum healing period of 6 months, radiographic bone height gain was assessed. One sinus membrane perforation was observed during VSA surgery. The mean vertical bone gain was 4.82 ± 1.31 mm and 8.36 ± 1.45 mm for VSA and LSA, respectively, with 100% implant success rate. OM-assisted maxillary sinus augmentation provides favorable clinical visualization, thus facilitating delicate hard and soft tissue manipulation.

Bone-Targeted Pharmacological Inhibition of Notch Signaling As a Novel Approach to Inhibit Myeloma Growth and Bone Destruction

Notch signaling between myeloma cells and cells of the bone marrow microenvironment favors growth and survival of myeloma cells and increases osteoclast formation. In vitro and in vivo studies demonstrated that systemic inhibition of Notch signaling using gamma-secretase inhibitors (GSIs) decreases myeloma cell growth and reduces osteoclast generation. However, the use of GSIs in the clinic is limited by the ocurrence of severe adverse side effects as fatigue, skin disorders, and acute gastrointestinal toxicity. To circumvent the side effects associated with systemic inhibition of Notch signaling using GSIs, we synthesized a novel Notch inhibitor by linking GSI-XII to an inactive bone-targeting molecule (BT). BT-GSI was designed to direct the conjugate to bone where the linker is cleaved under the acidic environment generated by osteoclast activity, thus locally releasing the GSI.In vitro, the control unconjugated GSI decreased Notch target gene expression (Hes1) in 5TGM1 myeloma cells, but BT-GSI had no effect. However, when both GSI and BT-GSI were pre-incubated at low pH to mimic the acidic conditions in resorption sites, equal inhibition of Notch target gene expression was observed. Ex vivo, both GSI and BT-GSI (non-pre-incubated) similarly decreased Hes1/5 expression in whole bone organ cultures that reproduce conditions present in the bone microenvironment. In vivo, administration of BT-GSI (5µg/g, 3xwk) to normal 4-month old female mice for 2 weeks was well tolerated and no skin issues were observed. Mice treated with BT-GSI exhibited decreased Hey2, Hes5, and Hes7 mRNA expression in whole bone preparations, but not in brain or gut, compared to vehicle-treated mice. Further, BT-GSI did not increase Apsidin expression in the gut, a biomarker of gastrointestinal toxicity. BT-GSI-treated mice exhibited decreased serum levels of CTX (-40%), a bone resorption marker, and upregulated Opg mRNA expression in bone, thereby decreasing the Rankl/Opg ratio. Consistent with these findings, BT-GSI-treated mice exhibited a 50% decreased in the bone surface covered by osteoclasts compared to vehicle-treated control mice. BT-GSI treated mice exhibited higher total (+3%), femoral (+4%), and spinal (+7%) BMD compared to control mice. Further, mice receiving BT-GSI had increased cancellous bone volume (+25%) and trabecular thickness (+10%) compared to vehicle-treated mice, as quantified by microCT. Serum levels of the bone formation marker P1NP, as well as bone formation and mineral apposition rates, number of osteoblasts, and the expression of osteoblast markers, including Wnt target genes and the osteocyte- derived Sost/Sclerostin remained unchanged in bones of BT-GSI-treated mice compared to control mice.Taken together, these findings demonstrate that BT-GSI induces bone specific Notch inhibition, reduces osteoclast formation without affecting osteoblast activity, favoring bone gain, and lacks gut toxicity. Thus, BT-GSI is a promising approach to inhibit the growth of myeloma cells and prevent bone loss in myeloma patients, while circumventing the deleterious side effects of this class of inhibitors in other tissues. DisclosuresDelgado-Calle:PharmaMar: Research Funding. Roodman:PharmaMar: Research Funding. Bellido:PharmaMar: Research Funding.