Bone Volume Assessment Around Immediate Dental Implant in the Esthetic Area with Immediate Tooth-Like Single Crown Provisionalization: A Laser and Computed Tomography 1-Year Retrospective Study.

PURPOSE: To examine the remodeling process of both the soft and hard tissue components of the postextraction socket around immediately loaded dental implants after tooth extraction in maxillary esthetic areas. MATERIALS AND METHODS: Subjects underwent immediate placement of single implants in postextraction sockets without bone grafting, and their immediate provisionalization with custom tooth-like interim crowns were fabricated using digital diagnostic impressions and a dental milling machine. Intraoperative and 1-year follow-up layered scans of the postextraction sockets after implantation were acquired using a 3D optical system. In the short term, subjects underwent computed tomographic scans. Digital impressions for gingival contours, originally stored as STL (standard tessellation language) files, were converted to DICOM (Digital Imaging and Communications in Medicine) files with the implant shoulder working as a referral point, which were then superimposed to 3D radiologic images. The observed volumetric and linear outcomes were measured using a program known as DentaScan. The width of the alveolar crest at the level of the implant shoulder and marginal bone levels were acquired. Nonparametric tests were applied with a level of significance set at P < .01. RESULTS: No failure was reported after a follow-up of 1 year. Little or no inflammation of the treated areas was registered, and there were practically no signs of suppuration. The areas showed a significant reduction in the overall volumes for both soft and bone tissue, with a P value < .0001 from the baseline (0.983 ± 0.172 cm3) to the 1-year survey (0.865 ± 0.156 cm3). If the soft and bone tissue changes were separately evaluated, a significant loss (with a P value < .0001) was registered for only the bone tissues (from 0.434 ± 0.075 to 0.355 ± 0.061 cm3). Moreover, changes in gingival tissue from baseline to the 1-year survey (-0.040 ± 0.067) appeared to be significantly different from the overall volume loss (-0.118 ± 0.083 cm3). A shrinkage in width (-0.5 ± 0.7 mm) was found from baseline (12.6 ± 0.6 mm) to the 1-year follow-up (12.1 ± 0.9 mm). Marginal bone levels were 0.97 ± 0.70 mm and 0.39 ± 0.78 mm, respectively, at the mesial and distal aspects of the implants. CONCLUSIONS: The present analysis suggested that immediately customized provisionalization was effective enough to prevent both volume loss and linear shrinkage at the layers of the treated areas. Moreover, the buccal aspects seemed to be the areas most affected by the loss of volume. The mean loss in width, which amounted to roughly 0.5 mm, appeared to be negligible when compared to the overall width measured before surgery.

Conventional avulsion versus less traumatic extraction of ankylosed roots with a magnetoelectric device in anterior maxillary areas.

The analysis aimed to compare two different single-tooth extraction surgical approaches in anterior maxillary areas of the ankylosed teeth: less traumatic magneto-electrical (mag) versus conventional tooth extraction (con) in minimizing the adverse effects on post-extractive sockets. Parameters of clinical interest such as intra-surgical fracture of the buccal bone plate, presence of postoperative inflammation, and application of stitches were acquired from medical records. The data were subjected to Pearson's χ2 analysis or to Fisher's exact test with significance at 0.05. Sixty-six hopeless maxillary permanent ankylotic teeth were extracted in the same number of patients. In the mag group 2 incisors suffered a fracture. Two patients out of 40 had signs and symptoms of inflammation that resolved completely within 3 days. In the con group 18 out of 26 patients suffered from buccal alveolar fracture. Six of these patients experienced signs of inflamed tissue. The two groups showed significant differences with p-values ≤0.0009 with regards to fracture (2/38 vs. 18/8) and tissue inflammation variables (2/38 vs. 10/16). A significantly different distribution about the presence of sutures was registered between the mag (4/36) and the con (18/8) group with a p-value <0.0001. Mag group seemed to have reduced frequency of fractured and infected post-extractive sites.

Assessment of the alveolar bone loss in fresh socket implant procedures with immediate implant loading via temporary preformed anatomical healing caps: Comparison of two different lengths of the implant collar.

PURPOSES: The aim of the present clinical and radiologic retrospective study was to evaluate alveolar bone remodeling, in terms of alveolar width and peri­implant bone level, two years after immediate implant positioning (with two different collar lengths, 0.8 mm and 2.0 mm) and loading of preformed healing cap. The Null hypothesis, H0 is: there was no difference between the two groups of implants. METHODS: Patients suffering from single-tooth edentulous areas in premolar, cuspid, and incisive areas were treated with fresh-socket implants and immediate preformed anatomical healing caps. Each final crown restoration was fabricated 3 months later. Primary outcomes (related to loss of the alveolar width and peri­implant bone level) and secondary outcomes (testing adverse events, and measuring implant/prosthesis survival) were acquired and analyzed. RESULTS: A two-year retrospective analysis was conducted on 31 patients (19 female and 12 male), who underwent dental implant placement with implants having two different lengths of the collar: group A, 0.8 mm, and group B, 2.0 mm. As for the width of the alveolar crest, there was a negligible loss (less than half a millimeter) reported for both the groups, anyway reaching a statistical significance. Preoperative alveolar widths (9.50±0.67 mm and 9.45±0.90 mm, respectively for groups A and B) were different from the two-year alveolar widths (9.20±0.74 mm and 8.93±0.99 mm, respectively for groups A and B) with p-values ≤ 0.0049. When the marginal bone loss was assessed, significant differences were registered between the two procedure groups (-1.42±0.34 mm for group A and -0.11±0.15 mm for group B with a p-value < 0.0001). CONCLUSIONS: The proper design of a healing abutment was very important to preserve the emergence profile immediately after extraction and implant placement. The length of the implant collar used with an immediate healing abutment appeared to affect the preservation of the alveolar crest with predictable final results.

Bone assessment around the delayed dental implant with and without preformed anatomical caps: A 1-year retrospective case-control study.

PURPOSES: To investigate the amount of first-year peri­implant bone loss and the development of the papillae when delayed dental implants loaded with anatomic cover screw and those underwent conventional healing protocol were compared. METHODS: Edentulous healed sites had undergone delayed implants placement. In the anatomical cap group, patients were treated with a guided tissue healing, tooth-like cross-linkable acrylic resin caps had been immediately screwed on dental implants. The marginal loss of the alveolar bone height 1 year after surgery and Jemt's papillae index were obtained. Non-parametric statistics were performed with a level of significance of 1% RESULTS: Forty patients were included in the present retrospective analysis. After a follow-up of 1 year, none of the 40 included implants showed a failure. The Jemt's papilla index was 1.76±0.44 and 1.34±0.50 respectively for guided tissue healing and conventional healing group, without any significant difference. Within the first year of survey a bone loss of -1.27±0.26 mm for conventional healing treatment showed a statistically significant difference (p-value<0.0001) when it was compared to the negligible of the other group (-0.06±0.31 mm). CONCLUSIONS: A guided healing procedure with preformed caps seemed to give better outcomes regarding marginal bone loss and papilla index than those of conventional abutments.

Preformed customized healing abutments in biologically oriented preparation technique procedure: a 3-year retrospective case-control study.

AIM: To determine the 3-year clinical and dimensional change of the soft tissue following implant placement in healed sites before and after loading with either customized or conventional healing abutments. MATERIALS AND METHODS: Premolar/molar implants were immediately loaded with either provisional and customized abutments without finishing lines according to principles of the Biologically Oriented Preparation Technique (BOPT), test group, or conventional healing abutments, control group. Three months later, the definitive crowns were fabricated. Primary outcomes (changes in the soft tissue) and secondary outcomes (adverse events) had been registered. RESULT: Fifty out of 87 subjects originally included were finally selected for this retrospective analysis: 23 in the test and 27 in the control group. During the first days after surgery 2 adverse events of mucositis, one for each group, occurred. A Few technical complications such as unscrewing 4 screw-retained crowns were recorded. A significant increase in the alveolar width was observed in both groups (test = +2.5±0.5mm, and control = +1.0±0.9mm). The widths appeared to not be merely changed from 3 months to 3 years in both groups. There were no significant differences regarding the width of the keratinized mucosa measured at baseline and after follow-up. Jemt papilla index showed a higher increase in the test group compared with that of the control group. CONCLUSION: Within 3 years of the follow-up period, peri-implant soft tissue outcomes of single, immediately loaded implants with customized healing abutments showed better results in terms of thickness and width when they were compared with those of the conventional group. Side effects count (mucositis and dehiscence) appeared to be very similar between the two groups. In addition, customized healing abutments led to significant augmentation of the alveolar width more than twice that registered in the conventional group.

Specific use of the implant stability quotient as a guide to improve healing for patients who had undergone rehabilitation with fixed implant-supported dental prostheses.

PURPOSES: to develop a clinical approach to evaluating osteointegration around bone implants and try to determining which was the correct time of implant loading in different edentulous indications, that is, either properly positioned implants or implants "at risk", generally referred to as implants having increased probability of failure (namely those for which primary stability had been achieved via a time-consuming surgery). MATERIALS: Several implant-supported rehabilitation strategies, with or without bone augmentation procedures, were performed in the upper and lower arches: From 2 to 5 months following implant placement, the prosthetic restorations were performed. A resonance frequency analyzer allowed clinicians to measure intraoperative and postoperative implant stability, then the values of the implant stability quotient, ISQ, ranging from 0 to 100, were registered. ISQs were ranked into 3 levels: Green (ISQ ≥ 70), Yellow (60 ≤ ISQ < 70), and Red (ISQ < 60). Groups were subjected to Pearson's χ2 analysis, with YATES correction when necessary, with a significance level of 0.05. RESULTS: A total of 213 implants had been included. When the distribution of normalized values of ISQ registered for implants inserted in native bone and loaded at 2-3 months (5 Red, 19 Yellow, and 51 Green) was compared to that of native implants loaded after 4-5 months (4 Red, 20 Yellow, and 11 Green), a significative difference was found (p-value = 0.0037). At the time of loading, significance was lost. Significant clinical improvements on the distribution of normalized values of ISQ were apparent for both the implants placed in pristine and those placed in lifted sinuses; no significant differences were registered between the two groups. CONCLUSION: At the loading time, implants considered to be at risk behaved similarly to the native sites for which the overall prosthetic workflow took about few; results confirmed that the mandibular implants appeared to have higher stabilities when compared to maxillary implants at both the intraoperative and the postoperative surveys.

Clinical and radiographic evaluation of transalveolar two-step osteotome-mediated sinus floor elevation versus sinus augmentation with displacement of the palatal wall in lateral direction coupled to alveolar ridge split technique: A 3-year retrospective study.

INTRODUCTION: The present study aimed to examine the middle-term effects of transcrestal double-sinus elevation (TSFE) versus alveolar/palatal split expansion technique (APS) and simultaneous implant placement in the augmented sinus. NULL HYPOTHESIS: there were no differences between groups. MATERIAL & METHODS: Magnetoelectric device was used for bone augmentation and expansion techniques in long-standing edentulous patients with a deficiency in vertical height in the posterior maxilla (3mm to 4mm residual bone height): TSFE group, or two-stage process with a first transcrestal sinus floor augmentation and a second sinus floor elevation with immediate implant placement; APS group, or "dual split and dislocation" of the two cortical bony plates towards the sinus and palatal side. Volumetric and linear analyses were performed on the superimposed preoperative and postoperative 3-year computed tomography scans. The level of significance was set at 0.05. RESULTS: Thirty patients were selected for the present analysis. For both groups significant differences were found in the volume outcomes between baseline and 3-year follow-up, showing a gain of about +0.28±0.06cm3 for the TSFE group, and +0.43±0.12cm3 for the APS group, with p-values < 0.0001. However, an effective increase of the volume of the alveolar crest was registered just in the APS group (+0.22±0.09cm3). A significant increase in bone width was found in the APS group (+1.45±0.56mm with p-value < 0.0001); on the contrary, a slight width reduction of the alveolar crest was observed in the TSFE group (-0.63±0.21mm). DISCUSSION: TSFE procedure seemed to not affect the shape of the alveolar crest. APS procedures led to a higher increase of the volume available for dental implant placement and could be used in horizontal bone defects too.

Immediate Implant and Customized Healing Abutment for a Periodontally Compromised Socket: 1-Year Follow-Up Retrospective Evaluation.

Immediate dental implant placement with or without immediate loading is reported in daily dentistry and implantology, but these procedures are not common in the case of periradicular and periapical lesions around the tooth needed to be replaced. In the following retrospective evaluation, 10 cases with a 1-year follow-up were selected to propose the technique of an immediate provisional non-loading prosthesis being delivered on the same day of the post-extraction implant placement in multiradicular teeth affected by chronic periradicular and periapical lesions. Post-extractive sockets underwent immediate dental implant placement by filling the empty space with sterile, re-absorbable gelatin sponges. The widths of the alveolar ridge were measured on three-dimensional radiographs before and after the operation, 4 and 12 months later. Non-parametric statistics were performed to compare the outcomes over time with a level of significance of 0.05. Comparing the preoperative cross-sectional images of cone beam computerized tomography (CBCT) scans to the postoperative ones, it was noted that changes in the crestal ridge width, ΔCW, (compared to baseline) were negligible and not clinically appreciable. However, while ΔCW at 4 months appeared to be negative (-0.17 ± 045 mm), crestal width at 12 months was at the same level as the baseline (ΔCW = 0.02 ± 0.48 mm), with a significant difference between 4 and 12 months (p-value = 0.0494). Immediate implant placement with an immediate non-loading provisional customized healing abutment of polyether-ether-ketone placed into the post-extractive sockets with asymptomatic and large chronic periapical and periradicular lesions could represent a further treatment strategy for patients' rehabilitation and soft tissue preservation to replace a hopeless tooth.

Volume assessment of the external contour around immediate implant with or without immediate tooth-like crown provisionalization: A digital intraoral scans study.

PURPOSES: To examine differences between immediate and delayed dental implant loading in maxillary aesthetic areas. METHODS: In this retrospective controlled analysis, 43 subjects who underwent immediate placement of the dental implant in a post-extraction socket were ranked into either immediate (24 implants loaded with non-occlusal tooth-like profile provisional prostheses fabricated by virtual diagnostic impressions and an in-office dental milling machine) or delayed group (19 implants loaded with conventional cover screws and secondary intention healing). Intraoperatively and then four months later, scans of the external layers were acquired with an optical scanner. The width of the alveolar crest and Jemt papilla index were acquired. Non-parametric tests were applied with a level of significance set at p < 0.01. RESULTS: In both groups, the volumes and areas showed significant reductions from the baseline to the 4-month survey. Reductions in volume appeared to be statistically different between the two groups (-39±31 mm3 for the immediate and 89 ± 30 mm3 for the delayed group). The final Jemt papilla index appeared significantly different between the immediate (mesial, 2.5 and, distal, 3) and delayed groups (2 for both aspects). CONCLUSIONS: Immediate provisionalization significantly reduced volume loss and area shrinkage at the external layer when data were compared to a delayed rehabilitation strategy.

Changes in Alveolar Bone Width Following Immediate Implant and Fresh Socket Preservation with Xenogeneic Gap-Filling Material Versus Guided Tissue Healing with Anatomical Tooth-Shaped Caps: A 3-Year Retrospective Case-Control Study.

This study aimed to calculate the 3-year dimensional change in crestal bone width when dental implants placed in postextraction sockets underwent two alternative techniques for alveolar preservation. Fresh sockets that had undergone immediate implant placement were categorized into one of two groups depending on the procedure type. For the xenogeneic biomaterial grafted (BG) group, the gaps between the metallic implant surfaces and the bony walls were filled with corticocancellous porcine bone; in the anatomical cap group, in which patients were treated with guided tissue healing (GTH), cross-linkable acrylic resin caps were immediately screwed on the implants. Absolute measurements of the alveolar width were performed on 3D images acquired before tooth extraction (thereby ensuring correct surgical treatment) and 3 years after surgery. Nonparametric statistics were performed, with the level of significance set at 1%. The results of 46 implants (placed in 36 patients) were analyzed, and 100% survival rates were reported for both groups at 3 years postsurgery. Minor swelling of treated areas was observed the first few days of healing, but neither mucositides, dehiscence events, nor suppurations occurred. At 3 years postsurgery, loss in alveolar ridge width was higher for the BG group (-1.1 ± 0.6 mm) than for the GTH group (0.0 ± 0.3 mm); moreover, these changes were significantly different (P < .0001). This clinical and radiographic data analysis suggests that the implant sites that received a xenogeneic filling material were less effective in maintaining the preoperative alveolar bone width than sites that underwent GTH with immediate implants and anatomical tooth-shaped caps.

Lateral Displacement of Maxillary Sinus Palatal Wall: A 1-Year Retrospective Computerized Tomography Study.

PURPOSE: To examine the short-term outcomes of maxillary sinus augmentations consisting of laterally and apically displacing the palatal wall through a transcrestal approach. MATERIALS AND METHODS: The maxillary sinus floor was fractured in its palatal aspect by allowing a displacement in the buccal and apical direction with a magnetoelectric system. A medial displacement of the alveolar crest in its palatal bony plate was performed at the same time. Crestal bone change was investigated using superimposed preoperative and postsurgical computed tomography scans. Clinical and radiologic outcomes over 1 year were evaluated. RESULTS: A total of 18 implants were selected for retrospective volumetric and linear analyses. Sinus floor and alveolar bone augmentation surgery led to a significant increase in the bone volume (P = .0002) from 0.134 ± 0.060 cm3 to 0.639 ± 0.166 cm3, with an overall gain of +0.504 ± 0.139 cm3. No part of the implant apices appeared to protrude into the maxillary sinus at the 1-year follow-up. The width of the alveolar crest changed from 5.1 ± 0.5 mm to 6.5 ± 0.7 mm, with a significant increase of +1.4 ± 0.6 mm registered at 1 year. However, a marginal bone loss of 1.0 ± 0.8 mm was observed. When tooth positions were investigated, no significant differences between the two groups (premolars versus molars) were found. CONCLUSION: Significant and effective bone gains allowed proper placement of the dental implants but with a minimal loss of peri-implant bone volume.

Guided Tissue Healing by Preformed Anatomical Healing Caps in the Edentulous Ridge: A 2-Year Retrospective Case-Control Study.

The present study evaluated the 2-year changes in soft tissue width after implant placement in healed sites, using two different methodologies to obtain tissue healing: preformed and anatomical abutment caps for customized healing (test) vs conventional healing abutments (control). The null hypothesis was that there would be no difference between the test group and the control group. Patients who suffered from a single-tooth edentulous area in the premolar/molar region were included. Both the standard abutments and the preformed and anatomical abutment caps were immediately screwed on the implants. The final crown restoration was fabricated 3 months later. Primary outcomes (changes in the alveolar soft tissue ridge) and secondary outcomes (testing adverse events and measuring implant/prosthesis survival) were evaluated. Thirty-nine patients (24 women) with a mean age of 57.7 ± 7.1 years (range: 42.6 to 72.8 years) were included. Alveolar widths in both groups showed significant increases from baseline to the 3-month follow-up, with augmentations of 3.6 ± 0.7 mm for the test group and 1.1 ± 0.9 mm for the control group. The gain in soft tissue appeared to be statistically different between the two groups (P < .0001). Contrarily, any subsequent change in width from 3 months to 2 years was negligible and insignificant (< 0.33 mm for both groups). The technique described in the present study encourages the potential for alternative healing based on the guided soft tissue concept, as it either eliminated the need for second-stage surgery or it reduced step-by-step peri-implant soft tissue conditioning, obtaining a tissue contour immediately very similar to that of a final prosthesis.

A Retrospective Digital Analysis of Contour Changing after Tooth Extraction with or without Using Less Traumatic Surgical Procedures.

BACKGROUND: The present retrospective analysis aimed to compare two different single tooth extraction surgical approaches in both premolar and molar areas: less traumatic magneto-electrical versus conventional tooth extraction in minimizing the edentulous ridge volume loss. METHODS: In the present retrospective control trial, 48 patients who underwent one-tooth extraction, were allocated either to control (28 sites treated with conventional tooth extraction procedures) or test group (20 subjects treated with less traumatic tooth extraction procedures by tooth sectioning and magnetoelectric roots subluxation). Intraoperatively (during tooth extraction surgery just after the subsequent filling of the alveolar socket with the sterile fast re-absorbable gelatin sponge), and then four months later, contours of the sockets were acquired through a laser intra-oral scanner. The digitally superimposed models were converted to dicom (Digital Imaging and Communications in Medicine) format first, then volumetric and area evaluations were performed with a DentaScan tool package. Non-parametric tests were applied with a level of significance set at p < 0.01. RESULTS: significant reductions of anatomical features were observed four months later in all the groups (p-values < 0.001) with volume losses leading to a final alveolar ridge volume of 0.87 ± 0.34 cm3 for atraumatic extractions and 0.66 ± 0.19 cm3 for conventional extractions. No significant differences were registered for outcomes related to the basal surface variables. When just molar tooth were considered, the outcomes relating to volume loss between baseline and four months (ΔV) and its percentage (ΔV%) showed a better behavior in the less traumatic procedure (ΔV = -0.30 ± 0.10 cm3 and ΔV% = -22.3 ± 8.4%) compared to the conventional extractions (ΔV = -0.59 ± 0.10 cm3 and ΔV% = -44.3 ± 5.8%) with p-values < 0.0001. CONCLUSIONS: at four months, the less traumatic tooth extraction procedures by tooth sectioning and magnetoelectric root subluxation seemed to be able to better preserve the volume of the alveolar crest (reduction close to 22% with less traumatic extraction in molar sites) when compared to subjects treated with the conventional tooth extraction techniques.

Maxillary and Mandibular Split Crest Technique with Immediate Implant Placement: A 5-Year Cone Beam Retrospective Study.

PURPOSE: This study aimed to test the effectiveness and reliability of the alveolar ridge-splitting technique in atrophic posterior arches, investigating the middle-term volumetric and clinical outcomes. MATERIALS AND METHODS: Atrophic alveolar ridges in the maxillary and mandibular posterior areas were treated with the alveolar ridge-splitting/expansion technique (ARST), immediate implant placement, collagen sponges covering the defect, and healing by secondary intention. Areas were rehabilitated by fixed dental prostheses supported by dental implants. Changes in volume and width of the alveolar ridge were retrospectively calculated by comparing the x-ray tomography scans obtained before and 5 years after surgery. Report of failure in the case sheets was taken into account. Cross-sectional images were also used to assess the thickness of the labial alveolar plates at the implant shoulder. Nonparametric analyses of variance with post hoc and pair-comparison tests were performed with a level of significance of .05. RESULTS: A total of 38 patients were retrospectively selected (23 women and 15 men). Six patients underwent ARST surgeries in both the maxilla and the mandible and were excluded from statistical analysis. Differences between 16 maxillae and 16 mandibles and between 12 single crowns and 20 fixed partial dentures (FPDs) were searched. Episodes of minor swelling occurred within the first 2 days after surgery. Neither mucositis nor flap dehiscence had been registered. The mean values of buccal cortical thickness were 2.46 ± 0.49 mm and 1.15 ± 0.33 mm, respectively, in the maxillary and mandibular areas. After 5 years of survey, maxillary increases in alveolar ridge width and volume were +4.4 ± 0.4 mm and +295 ± 45 mm3, respectively, whereas the same outcome variables (+3.5 ± 0.7 mm and +217 ± 53 mm3) measured in the mandible appeared to be significantly smaller than those in the maxilla (P < .0001). One maxillary single implant failed. Cumulative survival rates at 5 years were 100% for mandibles and 95.5% (95% CI: 86.8% to 100%) for maxillae. CONCLUSION: Posterior areas of the maxilla displayed a higher increase in alveolar width and volume than mandibular areas, and even if it would be premature to draw survival conclusions at this stage without any statistical support, a lower cumulative survival rate was reported for the maxillary single implants.

Clinical and Radiographic Evaluation of Modified Transalveolar Two-Step Osteotome-Mediated Localized Maxillary Sinus Elevation: A Retrospective Computed Tomography Study with a 3-Year Follow-up.

PURPOSE: This study aimed to report a practicable and noninvasive two-stage technique for sinus elevation and delayed implant insertion in the augmented site with residual bone height down to 3 mm or even lower. MATERIALS AND METHODS: The surgical technique employed a two-stage process for rehabilitation of posterior maxillary single-tooth edentulous areas, involving, in the first step, transcrestal maxillary sinus floor augmentation with a collagen sponge to fill the intrabony cavity resulting from the detachment of the sinus membrane; the second step consisted of another indirect sinus floor elevation using magnetoelectric surgery with immediate implant placement and no grafting material. Changes in bone height were evaluated by a comparison of the computed tomography scans acquired before treatment and after surgery (at 3 months and 5 years of the survey). Statistically significant differences between the times and the tooth sites were evaluated by nonparametric statistics (matched and independent), with P < .01. RESULTS: Forty patients were retrospectively selected. The preoperative height of the available alveolar bone was 2.9 ± 0.6 mm. A significant increase in bone height (P < .01) was found for both the first and the second surgery (3.1 ± 0.6 mm and 4.4 ± 0.6 mm, respectively). The overall bone height was measured at 3 years after the first surgery (10.3 ± 0.6 mm). Measurements of the bone height ranked for tooth positions showed no significant difference between premolars and molars. None of the selected patients registered an implant failure. CONCLUSION: Two-stage osteotome-mediated sinus elevation appeared to be a predictable technique that enabled practitioners to increase the bone height and to obtain successful outcomes even if the amount of bone was approximately 3 mm in height.

Standardization of three-dimensional pose of cylindrical implants from intraoral radiographs: a preliminary study.

BACKGROUND: To introduce a theoretical solution to a posteriori describe the pose of a cylindrical dental fixture as appearing on radiographs; to experimentally validate the method described. METHODS: The pose of a conventional dental implant was described by a triplet of angles (phi-pitch, theta-roll, and psi-yaw) which was calculated throughout vector analysis. Radiographic- and simulated-image obtained with an algorithm were compared to test effectiveness, reproducibility, and accuracy of the method. The length of the dental implant as appearing on the simulated image was calculated by the trigonometric function and then compared with real length as it appeared on a two-dimensional radiograph. RESULTS: Twenty radiographs were analyzed for the present in silico and retrospective study. Among 40 fittings, 37 resulted as resolved with residuals ≤ 1 mm. Similar results were obtained for radiographic and simulated implants with absolute errors of - 1.1° ± 3.9° for phi; - 0.9° ± 4.1° for theta; 0° ± 1.1° for psi. The real and simulated length of the implants appeared to be heavily correlated. Linear dependence was verified by the results of the robust linear regression: 0.9757 (slope), + 0.1344 mm (intercept), and an adjusted coefficient of determination of 0.9054. CONCLUSIONS: The method allowed clinicians to calculate, a posteriori, a single real triplet of angles (phi, theta, psi) by analyzing a two-dimensional radiograph and to identify cases where standardization of repeated intraoral radiographies was not achieved. The a posteriori standardization of two-dimensional radiographs could allowed the clinicians to minimize the patient's exposure to ionizing radiations for the measurement of marginal bone levels around dental implants.

Retinoblastoma Is Characterized by a Cold, CD8+ Cell Poor, PD-L1- Microenvironment, Which Turns Into Hot, CD8+ Cell Rich, PD-L1+ After Chemotherapy.

Purpose: To investigate the impact of chemotherapy (CHT) on human retinoblastoma (RB) tumor microenvironment (TME). Cases and Methods: Ninety-four RBs were studied, including 44 primary RBs treated by upfront surgery (Group 1) and 50 primary RBs enucleated after CHT (CHT), either intra-arterial (IAC; Group 2, 33 cases) or systemic (S-CHT; Group 3, 17 cases). Conventional and multiplexed immunohistochemistry were performed to make quantitative comparisons among the three groups, for the following parameters: tumor-infiltrating inflammatory cells (TI-ICs); programmed cell death protein 1 (PD-1) positive TI-ICs; Ki67 proliferation index; gliosis; PD-1 ligand (PD-L1) protein expression; vessel number. We also correlated these TME factors with the presence of histological high-risk factors (HHRF+) and RB anaplasia grade (AG). Results: After CHT, a decrease in both RB burden and Ki67 positivity was observed. In parallel, most subsets of TI-ICs, PD-1+ TI-ICs, gliosis, and PD-L1 protein expression significantly increased (P < 0.001, P = 0.02, P < 0.001, respectively). Vessel number did not significantly vary. Age, HHRFs+ and AG were significantly different between primary and chemoreduced RBs (P < 0.001, P = 0.006, P = 0.001, respectively) and were correlated with most TME factors. Conclusions: CHT modulates host antitumor immunity by reorienting the RB TME from anergic into an active, CD8+, PD-L1+ hot state. Furthermore, some clinicopathological characteristics of RB correlate with several factors of TME. Our study adds data in favor of the possibility of a new therapeutic scenario in human RB.

In-vitro fatigue and fracture performance of three different ferrulized implant connections used in fixed prosthesis.

BACKGROUND/PURPOSE: The aim of the present in vitro study was to evaluate fatigue resistance of dental fixtures in three different types of fixture/abutment finishing line. MATERIALS AND METHODS: Transmucosal dental implants, with or without ferrulized neck, underwent fatigue tests (static and dynamic load) using the following standard protocol: UNI EN ISO 14801:2016. Two types of loading devices (screw- or cement-retained restoration) were also tested, and fatigue cycle tests were run to failure. Data of static and dynamic load tests were analyzed by proper statistical methods. RESULTS: Following standard protocol for fatigue testing, the ILC type (Implant Level with ferrulized neck and cement-retained crown) showed a non-significant but higher Ultimate Failure Load (UFL = 445.7 N) compared to AL type (Abutment Level without ferrule effect, 421.6 N) and ILS type (Implant Level with ferrulized neck and Screw-retained crown, 362.8 N). No fracture of the titanium-base was registered in the tested specimens during the static loadings. Permanent deformations of the materials were observed. CONCLUSION: The number of cycles to either fracture or deformation (higher than 4 mm) occurring during fatigue tests showed that the stress rupture curve of the materials in group ILS appeared to be significantly different from those of the ILC and AL groups (p-values < 0.01): much higher life of one-half order of magnitude.

Distal Displacement of Maxillary Sinus Anterior Wall Versus Conventional Sinus Lift with Lateral Access: A 3-Year Retrospective Computerized Tomography Study.

BACKGROUND: The present study is designed to compare the outcomes of two sinus augmentation procedures: distal displacement of the anterior wall versus standard sinus lifting and grafting with a lateral window approach. METHODS: In the displacement group, a localized surgical fracture of the sinus floor achieved through an electromagnetic device results in the distal displacement of the anterior wall. In the filling group, sinus lifting (with lateral access) and grafting with particulate xenogeneic bone substitute was performed. Bone volume beneath the maxillary sinus was investigated with computerized tomography after baseline and postoperative data superimposition. Clinical and radiological outcomes over three years had been evaluated. RESULTS: Forty-three dental implants were selected. The two sinus lift procedures significantly increased the bone volume (p-value ≤ 0.0017) in the displacement group from 1.17 ± 0.34 to 1.53 ± 0.39 cc, with a final bone gain of +0.36 ± 0.17 cc, and in the filling group from 1.24 ± 0.41 to 1.94 ± 0.68 cc, with a bone augmentation of +0.71 ± 0.31 cc. No events of dental implant bulging into the maxillary sinus occurred. Two implants failed early on in the filling group, attesting the 3-year survival rate of 92.6% (CI95%: 82.7-100%). Marginal bone loss at the distal aspect was 1.66 ± 0.72 and 1.25 ± 0.78 mm, respectively, for the displacement and filling groups, with a significant difference (p-value = 0.0497). CONCLUSION: Results showed a significant and effective bone gain around dental implants at a 3-year survey for both sinus augmented by backward displacement of the anterior wall (+34%) and sinus lifting and grafting with a lateral window approach (+57%).

Impact of Concave/Convergent vs Parallel/ Divergent Implant Transmucosal Profiles on Hard and Soft Peri-implant Tissues: A Systematic Review with Meta-Analyses.

PURPOSE: To systematically review the literature comparing marginal bone loss (MBL) and pink esthetic scores of implants with convergent or concave transmucosal profiles vs divergent or parallel profiles. MATERIALS AND METHODS: A PICO question was defined, and an electronic search was carried out in the MEDLINE/PubMed and Cochrane Oral Health Group databases. Studies documenting type of transmucosal profile (either tissue-level profiles or abutments) and soft and/or hard tissue outcomes of implants were considered eligible. Studies were selected on the basis of the inclusion criteria and quality assessments. A meta-analysis with subgroup analyses was performed. RESULTS: Five papers fulfilled the inclusion criteria, and four were eligible for meta-analysis. Significantly less MBL was found in concave/convergent groups, with a mean difference of 0.772 (95% confidence interval [CI]: 0.450 to 1.095; P < .001). In the subgroup analyses for platform-switching and platform-matching connections, a significant effect in favor of concave/convergent was detected, with a standardized difference in means of 1.135 (95% CI: 0.688 to 1.583, P < .001) when platform switching was considered. No significant effects were found for platform-matching connections. CONCLUSION: Within the limitations of this review, it is suggested that concave/convergent implant transmucosal profiles result in less MBL. No statistically significant results were obtained for soft tissue-related outcomes or for the platform-matching connection subgroup.