Bone Gain Research Articles

The “Sling” Technique for Horizontal Guided Bone Regeneration: A Retrospective Case Series

The aim of this retrospective case series was to present a new technique, called the “sling technique”, for massive horizontal alveolar ridge augmentation through the innovative use of an expanded polytetrafluoroethylene (e-PTFE) membrane to reduce the risk of biological complications related to membrane exposure. Materials and Methods: Eligible patients for implant rehabilitation with a horizontal bone defect were enrolled in our study. All patients were treated with our new GBR approach, called the “sling technique” (ST), which consisted of covering the vestibular side of the bone defect with a stretched e-PTFE membrane. This technique allowed the amplification of the membrane surface as long as the compression and the immobilization of the underlying graft material remained (1:1 autologous bone and bovine xenograft). The membrane was placed far from the surgical incision of the mucosa to avoid infective complications. Pre- and post-regenerative surgery CBCT scans were used to assess the tissue gain amount after the GBR. Results: A total of 10 patients (4 females, 6 males; age range: 45–60 years old) were enrolled in our study and 33 implants were placed in regenerated bone. An average of 4 mm bone gain was achieved using the ST. No membrane exposures or biological complications were registered during the post-operative healing period. After a 24-month follow-up, a 100% implant survival rate was observed without hard or soft tissue dehiscence. Conclusion: The e-PTFE membrane positioned with the “sling technique” gave satisfactory results in horizontal bone augmentation. Considering the small sample, further confirmations with larger studies are needed.

Bone cell-specific deletion of thyroid hormone transporter Mct8 distinctly regulates bone volume in young versus adult male mice.

Thyroid hormones are critical regulators of bone metabolism. Their cellular import is guided through transporter proteins, including the monocarboxylate transporter 8 (MCT8). Conditional Mct8 knockout in osteoblast and osteoclast precursors leads to trabecular bone gain in 12-week-old male mice. Given that thyroid hormones regulate both skeletal development and bone maintenance, we investigated the effect of bone cell-specific Mct8 deletion in 6-week-old (young) and 24-week-old (adult) male mice. Mct8 ablation in osteoclast precursors led to trabecular bone gain at the spine in 6-week-old animals compared to age-matched controls, whereas adult animals displayed a shift towards trabecular bone loss in both femur and vertebra. Mct8 deficiency in osteoprogenitors increased osteoblast numbers and trabecular bone mass at the spine of young mice, without skeletal differences between adult knockout mice and littermate controls. In contrast, young mice lacking Mct8 in late osteoblasts/osteocytes exhibited lower trabecular bone volume at the spine and femur compared to respective controls, but no differences were detected at 24weeks of age. In vitro studies of osteoblasts with Dmp1-Cre promotor driven Mct8 deletion showed no significant alterations of osteogenic marker gene expression and mineralization capacity suggesting that MCT8 is not crucial for osteoblast maturation. Overall, we observed mild effects with conditional Mct8 knockout on bone microarchitecture and bone turnover especially during growth implying a secondary role for MCT8 as a thyroid hormone transporter in bone.

Cyclic Adenosine Monophosphate (cAMP)-Dependent Phosphodiesterase Inhibition Promotes Bone Anabolism Through CD8+ T Cell Wnt-10b Production in Mice.

ABSTRACTCyclic adenosine monophosphate (cAMP)‐dependent phosphodiesterase (PDE) inhibitors such as pentoxifylline (PTX) suppress cAMP degradation and promote cAMP‐dependent signal transduction. PDE inhibitors increase bone formation and bone mass in preclinical models and are used clinically to treat psoriatic arthritis by targeting inflammatory mediators including activated T cells. T cell activation requires two signals: antigen‐dependent CD3‐activation, which stimulates cAMP production; and CD28 co‐stimulation, which downregulates cAMP‐signaling, through PDE activation. PDE‐inhibitors consequently suppress T cell activation by disrupting CD28 co‐stimulation. Interestingly, we have reported that when CD8+ T cells are activated in the absence of CD28 co‐stimulation, they secrete Wnt‐10b, a bone anabolic Wnt ligand that promotes bone formation. In the present study, we investigated whether the bone anabolic activity of the PDE‐inhibitor PTX, has an immunocentric basis, involving Wnt‐10b production by CD8+ T cells. When wild‐type (WT) mice were administered PTX, biochemical markers of both bone resorption and formation were significantly increased, with net bone gain in the axial skeleton, as quantified by micro‐computed tomography (μCT). By contrast, PTX increased only bone resorption in T cell knockout (KO) mice, causing net bone loss. Reconstituting T cell–deficient mice with WT, but not Wnt‐10b knockout (KO) CD8+ T cells, rescued bone formation and prevented bone loss. To study the role of cAMP signaling in Wnt‐10b expression, reverse‐transcription polymerase chain reaction (RT‐PCR) and luciferase‐reporter assays were performed using primary T cells. PDE inhibitors intensified Wnt‐10b promoter activity and messenger RNA (mRNA) accumulation in CD3 and CD28 activated CD8+ T cells. In contrast, inhibiting the cAMP pathway mediators protein kinase A (PKA) and cAMP response element‐binding protein (CREB), suppressed Wnt‐10b expression by T cells activated in the absence of CD28 co‐stimulation. In conclusion, the data demonstrate a key role for Wnt‐10b production by CD8+ T cells in the bone anabolic response to PDE‐inhibitors and reveal competing T cell–independent pro‐resorptive properties of PTX, which dominate under T cell–deficient conditions. Selective targeting of CD8+ T cells by PDE inhibitors may be a beneficial approach for promoting bone regeneration in osteoporotic conditions. © 2022 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Characterization of Dental Pulp Stem Cells Response to Bone Substitutes Biomaterials in Dentistry

Bone substitute biomaterials (BSBs) represent a promising alternative to bone autografts, due to their biocompatibility, osteoconduction, slow resorption rates, and the ability to define and maintain volume for bone gain in dentistry. Many biomaterials are tailored to provide structural and biological support for bone regeneration, and allow the migration of bone-forming cells into the bone defect. Neural crest-derived stem cells isolated from human dental pulp (hDPSCs) represent a suitable stem cell source to study the biological effects of BSBs on osteoprogenitor cells involved in the physiological bone regenerative processes. This study aimed to evaluate how three different BSBs affect the stem cell properties, osteogenic differentiation, and inflammatory properties of hDPSCs. Our data highlight that BSBs do not alter cell proliferation and stemness markers expression, nor induce any inflammatory responses. Bone metabolism data show that hDPSCs exposed to the three BSBs distinctively secrete the factors supporting osteoblast activity and osteoclast activity. Our data indicate that (i) hDPSCs are a suitable stem cell source to study the effects of BSBs, and that (ii) the formulation of BSBs may condition the biological properties of stem cells, suggesting their versatile suitability to different dentistry applications.

Restorative angle of zirconia restorations cemented on non-original titanium bases influences the initial marginal bone loss: 5-year results of a prospective cohort study.

AimTo assess radiographic, restorative, clinical and technical outcomes as well as patient satisfaction of directly veneered zirconia restorations cemented on non‐original titanium bases over 5 years.Material and MethodsTwenty‐four patients with a single missing tooth in the aesthetic zone were recruited. All patients received a two‐piece implant with a screw‐retained veneered zirconia restoration cemented extraorally on a titanium base abutment. Marginal bone levels (MBL), marginal bone changes, technical complications, patient satisfaction and clinical parameters including probing depth, bleeding on probing and plaque index were assessed at crown delivery (baseline), at 1 year (FU‐1) and 5 years (FU‐5) of follow‐up. To investigate the relationship between restorative angle and MBL as well as marginal bone changes (bone loss/bone gain), correlation tests and linear regression models were carried out.ResultsTwenty‐two patients were available for re‐examination at 5 years. The mean MBL amounted to 0.54 ± 0.39 mm at baseline, and to 0.24 ± 0.35 at FU‐5 (=bone gain) (p < .001). At FU‐1, a positive correlation (r = .5) between the mesial restorative angle and mesial MBL was found (p = .012). Marginal bone changes between baseline and FU‐1 at mesial sites were also positively correlated with the mesial restorative angle (r = .5; p = .037). Linear and logistic regression models confirmed that mesial marginal bone loss was significantly associated with the mesial restorative angle at FU‐1 (p < .05). At 5 years, these significant associations at mesial sites disappeared (p > .05). At distal sites, no correlations or associations between the restorative angle and MBL or marginal bone changes were found regardless of the time point. During the 5‐year follow‐up, 5 technical complications occurred, mainly within the first year and mostly chippings. All patients were entirely satisfied with their implant‐supported restoration at 5 years.ConclusionWithin the limitations of the present study, the restorative angle of implant‐supported crowns on non‐original titanium bases might influence the initial marginal bone loss but without affecting their favourable long‐term clinical performance. A restorative angle of <40° may limit the initial marginal bone loss at implant‐supported crowns with titanium bases.

İki kemik arttırım yönteminin karşılaştırılması

Aim: This study aims to compare Guided Bone Regeneration (GBR) performed using autogenous block graft to particulate autograft with xenograft from physicians’ and patients’ perspectives.Methods: 30 systemically healthy individuals participated in this study. GBR using block graft (GBR-BAX) was performed in 15 of the patients and GBR using particulate autograft with xenograft (GBR-PAX) was performed in the other 15 patients. Bone thickness was recorded preoperatively and in the 6th month postoperatively. Bleeding, hematoma, flap dehiscence, infection, and paresthesia were evaluated. Patients were requested to record pain intensity and swelling levels using the visual analog scale (VAS) on the 3rd, 7th, and 14th days after surgery. The swelling levels were also recorded by a clinician on the 3rd, 7th, and 14th days after surgery. The cost of the surgery, the time spent on preparing the patient for the surgery, the time spent during the surgery, and the fatigue levels of the physician resulting from surgery were also determined.Results: Both GBR-BAX and GBR-PAX provided significant bone gain. Bleeding, hematoma, flap dehiscence, infection, and paresthesia levels found also similar. Both techniques caused similar pain, swelling, and discomfort on the 3rd, 7th, and 14th days. VAS results showed no differences in terms of pain and discomfort. GBR-BAX was found more time-consuming in both preparation and surgical period and tiring for the physician but was less costly compared to GBR-PAX. Conclusion: Within the limitation of the present study, GBR with autogenous block graft and particulate autograft plus xenograft provided similar bone gain and caused similar complications, pain, and discomfort. In terms of efficacy, none of the two techniques was found superior to the other; however, block graft was more time-consuming, tiring, and costly.

Evaluation of Sinus Membrane Perforation in Osteotome Sinus Floor Elevation With and Without Grafting.

The purpose of this study was to evaluate, using cone-beam computerized tomography (CBCT), the rate of sinus membrane perforation in osteotome sinus floor elevation (OSFE) performed with and without a graft material. Thirty patients with 52 OSFE sites were included in the study. Patients were divided into the control group (OSFE performed without graft material) and test groups (OSFE performed with autograft or xenograft). The autograft was harvested from the maxillary tuberosity using bone forceps. The xenograft was a commercial product originating from bovine bone. Graft volume was measured using the water displacement method. CBCT was performed at the initial examination and immediately after surgery to measure the residual bone height and to evaluate the endo-sinus bone gain and membrane perforation. The rate of sinus membrane perforation was 15.4%. Of the 52 OSFE procedures, 26.9% were performed without grafting and 34.6% and 38.5% were performed with autografts and xenografts, respectively. Membrane perforation was significantly higher in the autograft group (P = .033). The median volume of graft materials was 0.3 mL. The difference in graft volume between the autograft and xenograft was not statistically significant (P = .768). The mean endo-sinus bone gain was 6.55 mm in patients without membrane perforation and 8.71 mm in patients with membrane perforation; this difference was statistically significant (P = .035). The volume and physical properties of graft materials are important factors in membrane perforation. Further clinical studies with larger and standardized samples are needed to confirm the effect of graft materials on sinus membrane perforation in OSFE.

An Updated Decision Tree for Horizontal Ridge Augmentation: A Narrative Review.

Horizontal ridge augmentation is a common surgical procedure performed prior to or simultaneously with implant placement, depending on the extent of the ridge deficiency. Many horizontal augmentation surgical options have been developed, spanning a wide range of materials and techniques. Given the numerous permutations available, the most suitable strategy to regenerate ridge width for an individual case often confounds clinicians. Based on an extensive review of the literature, this article provides up-to-date technique selection guidelines, in the form of a decision tree, for predictable horizontal bone augmentation dependent on the amount of bone gain needed.

Periosteal Pocket Flap technique for lateral ridge augmentation. A comparative pilot study versus guide bone regeneration

BackgroundImplant rehabilitation of posterior mandibular defects is frequently associated to a horizontal bone loss. There exist several regenerative techniques to supply this bone deficiency, one of which is the Periosteal Pocket Flap Technique (PPF) proposed by Steigmann et al. to treat small horizontal bone defects. The present study proposes a modification of this technique based on the concurrent use of PPF with the use of xenogeneic and autologous bone and Plasma Rich in Growth Factors (PRGF). The aim of this study is to evaluate clinical and radiographic outcomes of the PPF with the use of xenogeneic and autologous bone and PRGF in comparison with conventional Guided Bone Regeneration (GBR) procedures. MethodsNine patients were enroled in the study (7 women and 2 men, mean age: 53 ± 2.74 years) and allocated to PPF or GBR. In both groups implant placement was performed simultaneously to bone regeneration. Preoperative CBCT scans were performed for each patient. Surgical time and postoperative pain were recorded, as well as tissue healing. Moreover, horizontal bone gain (mm), graft surface area (mm2) and graft volume (mm3) were evaluated. ResultsNine surgeries were performed: 6 PPF and 3 GBR. Regarding clinical outcomes, operative time was significative greater in GBR group than in PPF group (51.67 ± 3.51 min vs. 37 ± 5.69 min; p = 0.008). Postoperative pain was higher in GBR compared to PPF (p = 0.011). Regarding radiographical results, there were not significant differences in horizontal bone gain (PPF: 9.43 ± 1.8 mm; GBR: 9.28 ± 0.42 mm), surface area (PPF: 693.33 ± 118.73 mm2; GBR: 655.61 ± 102.43 mm2), and volume (PPF: 394.97 ± 178.72 mm3; GBR: 261.66 ± 118 mm3) between groups. ConclusionsThis prospective study demonstrates that the combination of autograft/xenograft and PRGF in PPF technique is a simpler, cheaper, and faster technique than GBR technique for achieving moderate lateral bone augmentation in implant treatment. Future randomised clinical studies are needed to confirm the results.

Sinus Lift by Lateral Approach versus Short and Extra-Short Implants: Split-Mouth Case Series

Introduction: The treatment of the atrophic posterior maxilla is a challenge, and there are different techniques for its rehabilitation with dental implants. In the present study we compare two of the most widespread: the classic lateral approach and transcrestal elevation. Material and methods: A retrospective open-mouth pilot study was carried out to evaluate the predictability of the two surgical techniques described above. To this end, patients in whom both techniques were used (one per quadrant) were followed up and a quantification of bone loss and gain over the implant apex was carried out, as well as an estimate of survival in both groups of implants. Results: Five patients were recruited and 13 implants were inserted (8 in conventional sinus lift and 5 in transcrestal sinus lift). The mesial bone loss of the implants studied at the end of the follow-up time was 0.40 mm in the mesial zone (+/- 0.23) and 0.50 mm in the distal zone (+/- 0.34) for implants placed in traditional elevations. For implants inserted in the transcrestal elevation the mesial bone loss of the implants studied at the end of the follow-up time was 0.30 mm in the mesial zone (+/- 0.13) and 0.20 mm in the distal zone (+/- 0.24). There were no statistically significant differences between the mean bone losses of both techniques (p=0.021). Conclusions: Both techniques have proven to be predictable for the treatment of the atrophic posterior maxilla in height. The use of short and extra-short implants and transcrestal elevation requires fewer surgeries and has a priori a lower risk of complications. In the patients of our split-mouth study we found no statistically significant differences between the two procedures.

A novel approach to treat peri-implantitis using sticky bone

Dental rehabilitation using implants sometimes lead to complications which ultimately leads to implant loss. With respect to peri‑implantitis, the non‑surgical mechanical therapy has not demonstrated to be equally effective. Therefore, surgical therapies have been proposed for treating peri‑implantitis. The aim of this procedure was to evaluate efficacy of using sticky bone - demineralized freeze dried bone allograft (DBDFA) + I-prf in management of a peri-implant defect. A full thickness flap was reflected, exposing the defect. Mechanical debridement of implant surface was done with Teflon curettes. After degranulation, implant surface was rinsed with 10% povidone iodine for 10 minutes. DFDBA + I-PRF was used to completely fill the defect and it was covered using a collagen membrane, Healiguide. 6 months post operatively, radiograph showed bone gain around the dental implant. DFDBA + Prf along with Healiguide shows promising results in treatment of peri-implantitis.

Effect of Bioactive Agents on Alveolar Ridge Augmentation: A Systematic Review and Meta-Analysis

&lt;p&gt;Objectives: This review aimed at investigating the impact of bioactive agents on alveolar ridge augmentation at peri-implant sites and edentulous ridges. Material and Methods: Electronic and manual literature searches were conducted for articles up to April 2021. Human randomized clinical trials, clinical trials, or retrospective studies reporting outcomes of alveolar ridge augmentation procedures with or without bioactive agents were included. Sinus lifting or extraction socket preservation articles were excluded in this study. A random-effect meta-analysis was conducted to investigate ridge dimensional changes and complication rate. Results: Overall, ten articles were included in the quantitative analysis. In bone width and height augmentation, the weighted mean difference (WMD) of the horizontal bone gain at edentulous ridges was 0.38 mm (95% CI = 0.07 to 0.69 mm, p = 0.02) when comparing sites with and without PRP/PRF. The WMD of the vertical bone gain at edentulous ridges was 0.46 mm (95% CI = 0.06 to 0.86 mm, p = 0.02) when comparing sites with and without platelet- rich plasma (PRP) or platelet-rich fibrin (PRF). When evaluating the effect of adjunctive use of bone morphogenetic proteins (BMPs) at alveolar ridge augmentation sites compared to alveolar ridge augmentation sites without BMP application, the WMD of the horizontal bone gain at edentulous ridges was 0.90 mm (95% CI = 0.30 to 1.49 mm, p = 0.003). In addition, the odds ratio of the titanium mesh exposure was 0.13 (95% CI of 0.02 to 0.71, p = 0.02). All analyses showed favorable outcomes at the sites with bioactive agent. Conclusion: Within the limits of this review, application of bioactive agents during alveolar ridge augmentation procedures presents increased horizontal and vertical bone augmentative changes. The complication rate can also be reduced with usage of PRP/PRF in titanium mesh-guided alveolar ridge augmentation.&lt;/p&gt; &lt;p&gt;&amp;nbsp;&lt;/p&gt;

Integrating Image Analysis and Dental Radiography for Periodontal and Peri-Implant Diagnosis

The recent change in classification of periodontal and peri-implant diseases includes objective evaluation of intra-oral radiographs and quantification of bone loss for disease staging and grading. Assessment of the progression of periodontal disease requires deduction of bone loss longitudinally, and its interpretation as (1) a percentage in relation to tooth root and (2) as a function of the patient's age. Similarly, bone loss around dental implants, after accounting for initial remodeling, is central for determining diagnosis, severity, and progression of peri-implantitis. Bone gain secondary to periodontal regeneration can be measured using standardized dental radiographs and compared to baseline morphology to determine treatment success. Computational image analysis, including machine learning (ML), has the potential to develop and automate quantitative measures of tooth, implant, bone volumes, and predict disease progression. The developed algorithms need to be standardized while considering pre-analytic, analytic, and post-analytic factors for successful translation to clinic. This review will introduce image analysis and machine learning in the context of dental radiography, and expand on the potential for integration of image analysis for assisted diagnosis of periodontitis and peri-implantitis.

Sinus Lift Associated with Leucocyte-Platelet-Rich Fibrin (Second Generation) for Bone Gain: A Systematic Review.

The purpose of this systematic review was to analyze sinus lifting procedures and to compare the efficiency of this treatment associated with the second generation of platelet-rich fibrin related to its effects on bone gain and to clarify the regenerative efficacy in sinus lift procedure, whether alone or as a coadjutant to other bone graft materials. The PICOT question was, “In clinical studies with patients needing a maxillary sinus lift (P), does the use of PRF either alone (I) or in conjunction with other biomaterials (C) improve the clinical outcome associated with bone gain and density (O), with at least three months of follow-up (T)?” An electronic search was conducted in the MEDLINE (PubMed), Science Direct, and Scopus databases through a search strategy. A total of 443 articles were obtained from the electronic database search. Sixteen articles met all criteria and were included in this review. Within the limitation of this study and interpreting the results carefully, it was suggested that a higher risk for implant failure after a sinus elevation might be seen in patients with residual bone ≤4 mm, and PRF application was effective, suggesting reducing the time needed for new bone formation.

Vertical ridge augmentation feasibility using unfixed collagen membranes and particulate bone substitutes: A 1- to 7-year retrospective single-cohort observational study.

AimTo determine whether vertical ridge augmentation (VRA) can be obtained through guided bone regeneration (GBR) using exclusively resorbable collagen membranes and particulate bone substitutes without additional stabilization.Materials and MethodsThis study retrospectively examined 22 participants who underwent VRA with staged or simultaneous implant placement. The vertical defects of all participants were filled with particulate bone substitutes and covered with resorbable collagen membranes. The augmented sites were stabilized with unfixed collagen membranes and the flap without any additional fixation. The augmented tissue height was assessed using cone‐beam computed tomography at baseline, immediately after surgery, and at annual follow‐ups.ResultsThe vertical bone gain of the 22 augmented sites amounted to 6.48 ± 2.19 mm (mean ± SD) immediately after surgery and 5.78 ± 1.72 mm at 1‐ to 7‐year follow‐up. Of the 22 augmented sites, 18 exhibited changes of less than 1 mm, while the other 4 showed changes of greater than 1 mm. Histological observation of three representative cases revealed new bone apposition on the remaining material.ConclusionThe present findings indicate that GBR procedures using exclusively collagen membranes and particulate biomaterials without any additional fixation are feasible options for VRA.

Evidence of re-osseointegration after electrolytic cleaning and regenerative therapy of peri-implantitis in humans: a case report with four implants

ObjectiveTo evaluate re-osseointegration after electrolytic cleaning and regenerative therapy of dental implants with peri-implantitis in humans.Material and methodsFour dental implants that developed peri-implantitis underwent electrolytic cleaning followed by regenerative therapy with guided bone regeneration. All four implants developed recurrent peri-implantitis and were therefore explanted 6 to 13 months later. Radiographic bone level, probing depth, and bleeding on probing were determined at the time of surgery, 6 months later, and before implant retrieval. The peri-implant tissues were histologically and histomorphometrically analyzed.ResultsAll four implants demonstrated radiographic and histological bone gain, reduced probing depth, and bleeding on probing. Radiographic bone gain was 5.8 mm mesially and 4.8 mm distally for implant #1, 3.3 mm and 2.3 mm for implant #2, 3.1 mm and 0.5 mm for implant #3, and 3.5 mm and 2.8 mm for implant #4. The histometric mean and maximum vertical bone gain for implant #1 to #4 was 1.65 mm and 2.54 mm, 3.04 mm and 3.47 mm, 0.43 mm and 1.27 mm, and 4.16 mm and 5.22 mm, respectively. The percentage of re-osseointegration for implant #1 to #4 was 21.0%, 36.9%, 5.7%, and 39.0%, respectively. In one implant, the newly formed bone was deposited directly onto calculus on the implant surface.ConclusionsWe found that (1) re-osseointegration is possible on a formerly contaminated implant surface and (2) the electrolytic cleaning process seems to be effective enough at sites with calculus residues.Clinical relevanceSince re-osseointegration can be achieved by electrolytic cleaning, this decontamination technique may be considered as a future treatment concept.

Computer-Guided Immediate Full-Arch Implant Reconstruction of the Mandible in Severe Periodontally Compromised Patients: Three-Dimensional Analysis of Bone Volume Changes.

Comprehensive rehabilitation in patients with severe periodontal destruction may require the use of dental implants. The primary aim of this study was to evaluate bone volume changes in periodontally compromised patients over a 12-month follow-up period after immediate full-arch implant reconstruction of the mandible. The secondary aim was to evaluate the repeatability of 3D bone volume change measurement methods around dental implants. The null hypothesis was that bone volume would decrease in the first year after delivery of the definitive prosthetic reconstruction. This retrospective study analyzed CBCT scans of 16 patients before and after computer-guided immediate full-arch implant reconstruction of the mandible. The bone volume change in the mandibular body and around the implants and the peri-implant bone area in coronal and axial cross sections were calculated. The average bone gain for the mandibular body was 3.3% ± 1.8%. The average bone volume increase in the peri-implant area was 23.2% ± 16.7%. The interobserver and intraobserver ICC values for 3D measurements were high (> 0.85). The null hypothesis was rejected. Both mandibular body and peri-implant surroundings undergo bone remodeling in the form of bone gain over 12 months after immediate implantation.

Natural History of Bone Disease following Kidney Transplantation.

Knowledge of the effect of kidney transplantation on bone is limited and fragmentary. The aim of this study was to characterize the evolution of bone disease in the first post-transplant year. We performed a prospective, observational cohort study in patients referred for kidney transplantation under a steroid-sparing immunosuppressive protocol. Bone phenotyping was done before, or at the time of, kidney transplantation, and repeated at 12 months post-transplant. The phenotyping included bone histomorphometry, bone densitometry by dual-energy x-ray absorptiometry, and biochemical parameters of bone and mineral metabolism. Paired data were obtained for 97 patients (median age 55 years; 72% male; 21% of patients had diabetes). Bone turnover remained normal or improved in the majority of patients (65%). Bone histomorphometry revealed decreases in bone resorption (eroded perimeter, mean 4.6% pre- to 2.3% post-transplant; P<0.001) and disordered bone formation (fibrosis, 27% pre- versus 2% post-transplant; P<0.001). Whereas bone mineralization was normal in all but one patient pretransplant, delayed mineralization was seen in 15% of patients at 1 year post-transplant. Hypophosphatemia was associated with deterioration in histomorphometric parameters of bone mineralization. Changes in bone mineral density were highly variable, ranging from -18% to +17% per year. Cumulative steroid dose was related to bone loss at the hip, whereas resolution of hyperparathyroidism was related to bone gain at both spine and hip. Changes in bone turnover, mineralization, and volume post-transplant are related both to steroid exposure and ongoing disturbances of mineral metabolism. Optimal control of mineral metabolism may be key to improving bone quality in kidney transplant recipients. Evolution of Bone Histomorphometry and Vascular Calcification Before and After Renal Transplantation, NCT01886950.

Extensive Gingivoperiosteoplasty Versus Secondary Alveolar Bone Grafting in Patients With Complete Bilateral Cleft Lip and Palate During the Mixed Dentition Period: A Retrospective Outcome Analysis.

The concept of gingivoperiosteoplasty (GPP) in the mixed dentition stage as compared with secondary alveolar bone grafting (ABG) in management of alveolar cleft has not been much discussed upon. The authors present the experience with extensive GPP and ABG in the mixed dentition stage in complete bilateral alveolar cleft cases. A retrospective review of nonsyndromic patients with complete bilateral alveolar cleft operated on with either GPP or ABG (iliac crest) in the mixed dentition stage with at least 1-year follow-up was performed. Dental occlusal radiographs were evaluated for level of bone gain using Bergland and Witherow scales. Statistical evaluation of clinical success and procedure-related complications was conducted using χ2 test and odds ratio. Twenty-four patients in the GPP group and 20 in the ABG group were comparatively studied. Clinical success rate as indicated by Bergland scales I and II (87.5% in GPP vs 82.5% in ABG; P = 0.731), complication rate (20.83% in GPP vs 30% in ABG; P = 0.484), and status of canine eruption showed no significant differences in clinical outcomes in both groups. The technique of extensive GPP as described by authors shows equal efficacy to secondary ABG for management of bilateral alveolar clefts during the mixed dentition period.

Surgical treatment of experimental peri-implantitis using mechanical and chemical decontamination procedures: A pre-clinical in vivo study.

To evaluate the effect of surgical treatment of experimental peri-implantitis at implants with different surface characteristics using mechanical and chemical decontamination methods. Following extraction of mandibular premolars, four implants with two different surface characteristics (A, moderately rough and B, smooth) were placed in each side of the mandible of six dogs. Experimental peri-implantitis was induced. Surgical treatment of the peri-implantitis sites was carried out using four implant surface decontamination protocols: (i) deposition of a citric acid gel, (ii) mechanical cleaning using a rotating titanium brush, (iii) a combination of the mechanical and chemical procedures, and (iv) saline (control). Clinical and radiographic examinations were performed. Block biopsies were obtained 6months after therapy and prepared for histological analysis. Irrespective of the treatment group, treatment resulted in 0.63 ± 0.92 and 0.65 ± 0.67 mm radiographic bone gain around implants A and B, respectively. Histological analyses revealed that persisting soft tissue inflammation as assessed using an infiltrated connective tissue (ICT) score was significantly lower at implant type B than at implant type A for all treatment groups. The test decontamination procedures did not demonstrate better results regarding resolution of peri-implantitis lesions, as indicated by the ICT scores, than the control procedure. The control treatment resulted in significantly superior outcomes of resolution of peri-implantitis lesions than the citric acid regimen. It is concluded that decontamination procedures including citric acid gel or rotating titanium brush did not improve outcomes following surgical treatment of experimental peri-implantitis. Results were, however, influenced by the implant surface characteristics.