International Journal of Periodontics & Restorative Dentistry, 1/2023
DOI: 10.11607/prd.6173Pages 75-83, Language: English
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.
The International Journal of Oral & Maxillofacial Implants, 5/2022
DOI: 10.11607/jomi.9594Pages 920-928, Language: English
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
International Journal of Periodontics & Restorative Dentistry, 5/2022
DOI: 10.11607/prd.6036Pages 639-646, Language: English
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.
The International Journal of Oral & Maxillofacial Implants, 5/2021
DOI: 10.11607/jomi.8572Pages 999-1007, Language: English
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
The International Journal of Oral & Maxillofacial Implants, 3/2021
Pages 553-560, Language: English
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
The International Journal of Oral & Maxillofacial Implants, 3/2020
DOI: 10.11607/jomi.7969, PubMed ID (PMID): 32406656Pages 576-584, Language: English
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
International Journal of Computerized Dentistry, 2/2020
SciencePubMed ID (PMID): 32555764Pages 109-117, Language: German, English
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
The International Journal of Oral & Maxillofacial Implants, 6/2019
DOI: 10.11607/jomi.7199, PubMed ID (PMID): 31711090Pages 1505-1511, Language: English
Purpose: To measure the volume effect on maintaining a sealing around immediately rehabilitated dental implants in a comparison between customized and conventional provisional crowns at a 3-year follow-up.
Materials and Methods: A single crown supported by a dental implant was used as a rehabilitation strategy for a failing tooth. The primary predictor was the type of immediate restoration with custom or conventional provisional crowns; a secondary predictor was tooth position: incisor, canine, or premolar. In order to accurately measure the width between buccal and palatal plates at the alveolar margin in a comparison between preoperative (before tooth extraction) and postoperative (at the 3-year follow-up) radiographs, two cone beam computed tomography (CBCT) scans were three-dimensionally analyzed and superimposed.
Results: Seventy-six patients, rehabilitated with single implants, were selected (31 implants belonging to the custom group and 45 to the conventional group). In patients treated with conventional restorations, a significant shrinkage (-0.6 ± 1.2 mm with P = .002) was registered. On the other hand, the bone change registered for the custom restoration group appeared negligible, with a nonsignificant and slight increase in width (+0.2 ± 0.7 mm). When the subgroups regarding the implant sites were investigated, the decrease in width was very limited for the canine tooth in the custom group (-0.3 ± 0.2 mm), whereas the shrinkage at the canine in the standard group appeared to be significantly higher (-1.5 ± 0.7 mm with P = .0001).
Conclusion: An anatomically contoured provisional restoration may provide a strategy to stimulate peri-implant soft tissue healing, minimize loss of buccal bone plate at the marginal level, and maintain pristine volume in the alveolar bone better than noncustomized restorations.
Keywords: CBCT, customized healing restoration, fresh socket implants, immediate loading, prosthetic procedure
The International Journal of Oral & Maxillofacial Implants, 4/2019
DOI: 10.11607/jomi.6972, PubMed ID (PMID): 30934043Pages 953-962, Language: English
Purpose: The purpose of this study was to assess the effect of different loading protocols (immediate or delayed) on bone volume remodeling of an immediate implant-supported single crown in the maxilla with a follow-up from 2 to 3 years.
Materials and Methods: Patients presenting a failing tooth were rehabilitated with implant-supported single crowns. Data of patients with a survey from 2 to 3 years after baseline surgery were retrospectively acquired. One implant per patient was randomly selected during data analysis and assigned to one of two predictor groups: the loading protocol, 9 immediate vs 13 delayed loading; and tooth position, 9 incisors vs 9 canines. Cumulative survival rates were recorded; loss of crestal bone volume was assessed with cone beam computed tomography (CBCT) by means of software that superimposed the preoperative and postoperative CBCT scan data (Matrix Laboratory) and by dentascan software.
Results: Twenty-two patients were enrolled. No postoperative complications or implant failures were recorded. Bone volume loss from the 2- to 3-year follow-up period ranged between 19.1% and 22.0%, without significant differences between the two loading protocols. Irrespective of the tooth site, intragroup analyses revealed the presence of significant differences between preoperative and postoperative time evaluations for all the analyzed groups and subgroups. Volumes at baseline (ranging between 0.546 and 0.553 mL) recorded significant loss of approximately 110 mm3 (P values ≤ .0001) for both loading protocols. The volume at the postoperative evaluation ranged between 0.428 and 0.442 cm3. Considering tooth site in the analysis, the subgroups showed similar behaviors at the crestal bone level. However, bone loss at the apex of the implant appeared to be lower for incisors than canines.
Conclusion: This study attested that the loss of crestal bone around an immediate implant-supported single crown depended on neither the loading protocol nor the tooth site.
Keywords: cone beam computed tomography imaging, extraction socket, fixed implant prosthesis, immediate loading, immediate placement
International Journal of Periodontics & Restorative Dentistry, 2/2019
DOI: 10.11607/prd.3292, PubMed ID (PMID): 29897351Pages 227-232, Language: English
The aim of the present study was to consider the long-term midfacial mucosal outcome around final prosthetic restorations on dental implants placed and loaded immediately after tooth extractions. A total of 42 patients requiring tooth extractions were recruited, and 142 teeth were extracted. Based on the amount of keratinized mucosa (KM), implants were categorized into group A (KM ≥ 2 mm; n = 61) or group B (KM < 2 mm; n = 62). In both groups, all patients received temporary prosthetic restorations immediately after the surgical procedure. Baseline levels were measured at placement of the final prosthetic restoration and patients were followed for 8 years. After the 8-year follow-up, a survival rate of 98.37% was reported. Two implants were lost due to peri-implantitis after 6 and 7 years of function, respectively. Peri-implantitis occurred at 9 implants (3 from group A and 6 from group B) in 8 patients (7.32%). At the 8-year followup for group A, an increase in midfacial tissue level of 0.14 ± 0.13 mm (screwed restorations) and 0.16 ± 0.09 mm (cemented restorations) was measured. For group B, a decrease in midfacial tissue level of 0.15 ± 0.09 mm (screwed restorations) and 0.17 ± 0.12 mm (cemented restorations) was reported. Statistically significant differences between groups were measured at 2, 5, and 8 years of follow-up (P < .01). The results demonstrated that the presence of KM is significantly associated with less mucosal inflammation and less gingival recession, regardless of the type of prosthetic restoration (screwed vs cemented).