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Purpose: This study aimed to conduct a radiological and clinical evaluation of patients who underwent fixed rehabilitation involving subperiosteal implants and to define not only the criteria for failure but also the criteria for survival and success. Materials and methods: Patients suffering from severe atrophy of the maxilla and/or mandible underwent immediate loading with fixed full-arch prostheses supported by custom-made 3D-printed subperiosteal implants. The evaluated outcomes included the success and survival rates of subperiosteal implant prosthetic therapy, surgical complications, and the three-dimensional positions of osteosynthesis screws and sleeves used for implant adhesion to the bone. The SIO criteria (Stability, Inflammation, and Offset) were used for evaluating the success, survival, or failure of subperiosteal implant-prosthetic rehabilitation. Success required no clinical mobility, asymptomatic soft tissues without recession, and no intraoperative deviations from virtual implant planning; while survival allowed transient micromovements, tissue recession without inflammation, and minimal post-surgical implant modifications. Persistent micromotion and implant removal due to aesthetic dissatisfaction or fabrication of a new implant were classified as failures. Non-parametric tests were applied to the datasets with a significance level of p = 0.01. Eighteen patients were followed up for two years. Eleven implants were placed in the upper jaw and 15 in the lower jaw. Temporary instability was observed in four subperiosteal implants, accounting for a survival rate of 84.6% based on the Stability criterion). Two patients suffered from peri-implant soft tissue recession at two years (Inflammation criterion). Preoperative virtual implant positions and achieved postoperative position of 189 titanium osteosynthesis screws and sleeves were analyzed: 98 buccal, 69 linguopalatal, and 22 in other areas. The overall linear sleeve misalignment was 1.66±0.99mm. Horizontal misalignment (1.46±1.03mm) was approximately three times greater than vertical misalignment (0.59±0.21mm), with a significant difference (p value=0.0004). One patient exhibited horizontal and overall misalignments exceeding the maximum threshold suitable for implant success (approximately 5 mm), resulting in 25 successful and only one surviving implant (Offset criterion). No prosthesis failed during the entire follow-up, and no mechanical or functional complications were recorded. The cumulative survival rate was 100% at the two-year follow-up. Conclusions: The proposed SIO criteria defined success, survival, and failure for subperiosteal implant rehabilitation. Transient movements or infection events were classified as survival indicators, while negative Offset results led the implant survival but not success. The present virtual design and planning approach achieved a 73.1% success rate over two years according to the SIO classification. Keywords: Stability-Infection-Offset criteria, subperiosteal implants, success code, fixed prosthesis, immediate loading

Aim: The objective of the present study was to determine the 3-year clinical and dimensional soft tissue change 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 the 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 (soft tissue changes) and secondary outcomes (adverse events) were registered. Results: A total of 50 of the 87 subjects who were originally included were finally selected for the present retrospective analysis: 23 in the test group and 27 in the control group. During the first days after surgery, two adverse events of mucositis occurred, one in each group. A few technical complications were recorded such as the unscrewing of four screw-retained crowns. A significant increase in the alveolar width was observed in both groups (test: +2.5 ± 0.5 mm; control: +1.0 ± 0.9 mm). The widths appeared unchanged 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. The Jemt papilla index showed a higher increase in the test group compared with the control group. Conclusions: Within the 3-year follow-up period, the peri-implant soft tissue outcomes of single, immediately loaded implants with customized healing abutments showed better results in terms of thickness and width compared with those of the conventional group. The number of side effects (mucositis and dehiscence) appeared to be very similar for both groups. In addition, customized healing abutments led to significant augmentation of the alveolar width, which was more than twice of that registered in the conventional group. Keywords: anatomical cap, customized abutment, dental abutment, dental implant, implant placement

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. Keywords: alveolar remodeling, immediate implant, intraoral digital scanning, imaging superimposition, immediate provisionalization, computerized tomography

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.

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. Keywords: bone displacement, computerized tomography image, dental implants, infracture technique, maxillary sinus

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.

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. Keywords: alveolar ridge split, alveoloplasty, bone remodeling, posterior mandible, posterior maxilla, secondary intention healing

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. Keywords: CBCT, dental implant, osteotome sinus elevation, single crown, two-step technique

Purpose: The purpose of this study was to compare success and outcomes among implants positioned either in grafted or ungrafted alveoli during 10 years of follow-up. Materials and Methods: This retrospective analysis was conducted on data of subjects who underwent tooth extraction and alveolar ridge preservation. Sites, one per patient, were ranked into three groups: postextraction ungrafted alveoli, and postextraction grafted alveoli with either synthetic magnesiumenriched hydroxyapatite or porcine bone. An absorbable collagen sheet was used to completely cover all the sockets. A secondary intention healing was sought for all procedures. Data regarding implant survival and marginal bone loss around implants were gathered until the 10-year follow up. Pairwise comparisons were performed with nonparametric tests, and statistical significance was set at .01. Results: Sixty-three subjects were included: 42 implants (19 and 23 in the magnesium-enriched hydroxyapatite and porcine bone groups, respectively) placed in grafted sites and 21 in nongrafted sites. The success rate of the grafted groups was 88.1% (CI: 78.3% to 97.9%) at the 10-year follow-up. On the other hand, in the ungrafted group, the overall success rate was 85.7% (CI: 70.8% to 100%). Peri-implant marginal bone loss at the 10-year follow-up for the magnesium-enriched hydroxyapatite group was 1.2 (0.7) mm, while for the porcine bone group, it was close to 0. The behavior of the ungrafted group appeared to be significantly different compared with both grafted groups; however, marginal bone levels ranging from 0.1 to 0.4 mm were observed from 3 to 10 years. Conclusion: A difference in terms of long-term success rates between grafted and ungrafted sites was not revealed. Bone loss was significantly higher in the magnesium-enriched hydroxyapatite grafted group compared with those in the other groups (without or with other bone substitute material). Keywords: bone graft, bone substitute, soft tissue management

Aim: To evaluate width loss of the alveolar ridge three years after implant placement in a fresh extraction socket following two different tissue healing methodologies: conventional healing procedure vs CAD/CAM technology for a customized healing abutment. Materials and methods: Post-extraction sockets underwent immediate dental implant placement without the voids being filled between the implant surface and the socket wall. Samples (one implant per patient) were retrospectively enrolled in each group according to the type of healing procedure: implants in the conventional group underwent standard closed healing with a cover screw, while in the customized group the healing abutment was immediately screwed onto the head of the implant, mimicking the look of the extracted tooth fabricated by CAD/CAM technology. The width of the alveolar ridge was measured on 3D radiographs at baseline (before surgery) and three years postsurgery. Nonparametric statistics were performed with a significance level of 0.01. Results: A total of 54 dental implants were selected. An implant survival rate of 100% was reported for all implants after 36 months. Three years after implant placement, loss in bone width was registered for both the conventional and customized groups, being 2.2 (1.1) and 0.2 (0.7) mm, respectively. Changes in the customized group were significantly lower than in the conventional group. Significant differences were again found between the groups for each of the tooth sites. Loss of bone width appeared negligible (from incisor to premolar), with values ranging between 0.2 and 0.4 mm in the customized group, whereas in the conventional group all tooth sites underwent wide shrinkage (with a bone loss ranging from 1.6 to 3.0 mm). Conclusion: The CAD/CAM procedure might provide the following advantages: 1) Stabilization of the gingival setting and bone volume in a fresh socket implant; 2) Maintaining the same emergence profile of teeth for restorative crowns, avoiding laboratory approximation of the emergence profile of the definitive restoration; and 3) Optimal prosthetic-surgical planning and minimally invasive extraction to preserve the integrity of the supporting tissue. Keywords: dental implant, immediate implant placement, dental abutment, customized abutment, cone beam computed tomography