International Journal of Periodontics & Restorative Dentistry, 4/2022
DOI: 10.11607/prd.5840Pages 515-522, Language: English
The objective of this study was to assess volumetric and linear changes of buccal mucosal thickness at implant sites following soft tissue augmentation with a volume-stable collagen matrix (VCMX). Soft tissue augmentation using a VCMX was performed in 12 patients at the time of implant placement. Hydrocolloid impressions were taken prior to surgery and at 1 and 6 months postsurgery. Stone cast models were scanned, and stereolithography (STL) files from the three time points were uploaded to an image-analysis software. At all time points, linear and volumetric measurements of the contour changes up to 3 mm apical to the mucosal margin were performed and were analyzed statistically. At 1 mm apical to the mucosal margin, the change in soft tissue thickness between presurgery (T1) and 1 month (T2) amounted to 0.21 ± 1.22 mm, and the change between T1 and 6 months (T3) was 0.08 ± 1.47 mm. At 3 mm apical to the mucosal margin, the change in soft tissue thickness was 1.92 ± 1.70 mm between T1 and T2 and 0.31 ± 1.26 mm between T1 and T3. Contour (volumetric) changes revealed an increase of 0.58 ± 0.73 mm between T1 and T2 and an overall gain of 0.55 ± 0.73 mm between T1 and T3. Soft tissue augmentation with VCMX increased the ridge profile. The increase in ridge width was greater at 3 mm below the ridge crest than at 1 mm below the ridge crest. Remodeling processes during healing showed a decrease in the ridge contour between 1 and 6 months.
The International Journal of Prosthodontics, 5/2021
DOI: 10.11607/ijp.6999Pages 560-566d, Language: English
Purpose: To assess the clinical, technical, and esthetic outcomes of directly veneered zirconia abutments cemented onto nonoriginal titanium bases over a 3-year follow-up.
Materials and Methods: A total of 24 healthy patients with a single missing tooth in the maxilla or mandible (incisors, canines, or premolars) received a two-piece implant with a screw-retained veneered zirconia restoration extraorally cemented onto a titanium base abutment. Baseline measurements and follow-up examinations were performed at 6 months, 1 year, and 3 years following loading. Radiographic, clinical, technical, and esthetic parameters were assessed. Wilcoxon signed rank test was used to analyze the data.
Results: Mean marginal bone levels measured 0.54 ± 0.39 mm (median: 0.47 mm, range: 0.07 to 1.75 mm) at baseline and 0.52 ± 0.39 mm (median: 0.39 mm, range: 0.06 to 1.33 mm) at 3 years. Mean probing depth around the implants increased from 3.0 ± 0.6 mm at baseline to 3.8 ± 0.8 mm at 3 years (P = .001). Bleeding on probing changed from 27.1% ± 20.7% at baseline to 51.5% ± 26.1% at 3 years (P = .001). The mean plaque control record amounted to 11.1% ± 21.2% at baseline and 14.4% ± 13.89% at 3 years (P = .261). Two implants were lost at 3.5 and 30 months postloading due to periimplantitis, resulting in a 91.7% implant survival rate. Patient satisfaction was high at 3 years.
Conclusion: Zirconia restorations cemented onto the tested nonoriginal titanium bases should not be recommended for daily clinical use, as they were associated with significant increases in BOP and PD values and varying marginal bone levels 3 years after placement.
The International Journal of Prosthodontics, 5/2020
DOI: 10.11607/ijp.6470, PubMed ID (PMID): 32956429Pages 487-492, Language: English
Purpose: The aim of the present study was to assess the perceptibility and acceptability threshold values for color differentiation at the restoration and mucosa levels.
Materials and Methods: One restored single-tooth implant and the contralateral reference tooth were spectrophotometrically assessed in 20 patients. Perceptibility and acceptability were evaluated by dentists, dental technicians, and laypeople.
Results: Dental technicians had the highest sensitivity in the perception of tooth color differences (ΔE = 2.7), followed by dentists (ΔE = 3.3) and laypeople (ΔE = 4.4). Acceptability threshold values were generally higher than perceptibility threshold in all groups. Dental technicians exhibited the highest sensitivity in the perception of mucosa color differences (50% perceptibility at ΔE = 2.65), followed by dentists (ΔE > 3.7) and laypeople (ΔE > 6).
Conclusion: Color differences were tolerated with varying degrees among the three groups. Laypeople accepted higher color differences at the mucosa level.
The International Journal of Prosthodontics, 5/2020
DOI: 10.11607/ijp.6737, PubMed ID (PMID): 32956431Pages 503-512, Language: English
Purpose: To assess the clinical outcomes of single-retainer resin-bonded fixed dental prostheses (RBFDPs) and the profilometric changes of pontic sites after a mean of 10 years in function.
Materials and Methods: Ten patients (mean age 32.4 years) who had received an RBFDP replacing a single anterior tooth were recalled after 10 years. Five patients had received a subepithelial connective tissue graft (SCTG) at the pontic site. The clinical assessment comprised the following parameters: probing depth, bleeding on probing, modified plaque control record, gingival recession, measurement of the width of keratinized mucosa, and intraoral photographs and radiographs. The modified criteria of the United States Public Health Services evaluation system were applied. Additionally, patient satisfaction was recorded. Data were analyzed descriptively, and the 10-year RBFDP survival rates were calculated using Kaplan-Meier analysis.
Results: The RBFDP survival rate after a mean follow-up of 10.0 years (range 7.4 to 13.3 years) was 100%. Neither technical failures nor biologic complications were observed. All abutment teeth remained vital, and no secondary caries were detected. Between baseline and follow-up examinations, the profilometric changes at the pontic sites were minimal, exhibiting a loss of –0.03 ± 0.10 mm (no SCTG) and 0.00 ± 0.37 mm (SCTG).
Conclusion: The present study exhibited high survival rates and low complication rates of the restorations, as well as excellent profilometric stability of the pontic sites over 10 years. The use of an RBFDP is a viable long-term treatment option for replacing a single anterior tooth.
The International Journal of Oral & Maxillofacial Implants, 5/2020
DOI: 10.11607/jomi.8211, PubMed ID (PMID): 32991652Pages 1005-1012, Language: English
Purpose: To clinically and histomorphometrically compare a biphasic calcium phosphate (BCP) and deproteinized bovine bone mineral (DBBM) for sinus floor elevation.
Materials and Methods: Sinus floor elevation procedures (lateral window) were performed randomly applying either BCP (test) or DBBM (control). At 6 months, bone biopsy specimens were harvested and dental implants were placed. The proportions of new bone, residual grafting material, and nonmineralized soft tissue were calculated. Four months after implant placement, the prosthetic reconstructions were inserted and the implant survival was assessed.
Results: Fifty-one patients were treated; 25 were randomly allocated to the BCP group and 26 to the DBBM group. After 6 months in 50 patients, bone biopsy specimens could be harvested, and a total of 121 implants could be placed subsequently. The histomorphometric analysis revealed a comparable percentage of new bone in both groups (BCP 35.9%, DBBM 35.4%; P > .05). The remaining grafting material was significantly lower with BCP (25.3%) compared with DBBM (45.9%; P < .001). Nonmineralized tissue was significantly higher for the BCP group (38.1%) compared with the DBBM group (18.2%; P < .001). The implant survival rate at loading was assessed at the level of the patients (96.0% for BCP and 88.8% for DBBM; P > .05) and at the level of the implants (96.9% for BCP and 94.7% for DBBM; P > .05).
Conclusion: Grafting with DBBM or BCP showed similar percentages of new bone 6 months after sinus floor elevation. Implant survival presented no significant difference until loading.
Keywords: biphasic calcium phosphate, bone grafting, bone substitute, deproteinized bovine bone, histomorphometry, maxillary sinus, randomized controlled trial, sinus floor elevation
International Journal of Periodontics & Restorative Dentistry, 4/2020
DOI: 10.11607/prd.4575, PubMed ID (PMID): 32559034Pages 519-527, Language: English
Peri-implant bone dehiscences were grafted either with deproteinized bovine bone mineral (DBBM) block or with particulate DBBM, both covered with a collagen membrane and stabilized with resorbable pins. After 6 months, 17 biopsy samples were included for histologic assessment. Block and particulate DBBM rendered successful tissue integration. Particulate DBBM showed a median of 25.2% of new bone and 31.3% of bone substitute. In the block group, there was a median of 11.5% of new bone and 36.0% of bone substitute. When interpreting the discrepancy in new bone between the groups, the difference in the size of the augmented hard tissue needs to be taken into account.
International Journal of Periodontics & Restorative Dentistry, 3/2019
Online OnlyDOI: 10.11607/prd.4146, PubMed ID (PMID): 30986285Pages e71-e82, Language: English
This paper performed time and cost analyses and compared conventional vs computer-assisted implant planning and placement (CAIPP) protocols when placing single implants in partially edentulous patients. Partially edentulous patients were randomly allocated to one of three treatment groups: preoperative planning based on a conventional two-dimensional radiograph and free-hand implant placement (control [C], n = 26) or computer-assisted implant planning based on three-dimensional (3D) computer-tomography (test group 1 [T1], n = 24; test group 2 [T2], n = 23). A surgical guide was produced by stereolithography in T1 and by 3D printing in T2. In all patients, open-flap implant placement procedures were performed. Time and costs derived from each working step were recorded for each treatment protocol. Descriptive and analytic statistics were used to display the data and uncover differences between treatment groups. Overall office time was similar in all groups (C = 63.8 min; T1 = 77.2 min; T2 = 81.7 min). CAIPP and conventional protocols required similar times to perform the preoperative diagnosis, radiographic exam, and implant surgery. CAIPP protocols required longer surgical planning and template-production times. Overall economic costs were 31% (T1) to 20% (T2) higher for the CAIPP protocols due to the radiographic investigation and the surgical template production (C = Swiss francs [CHF] 1,567; T1 = CHF 2,268; T2 = CHF 1,946). In the present indication and methodologic set-up, computer-assisted protocols did not show an advantage over conventional protocols in terms of time or financial savings. The temporal and financial expenses should be put into perspective to potential benefits.
Pages 165-170, Language: German
Der Einsatz von Keramikimplantaten hat in den letzten Jahren zugenommen und entspricht der generellen Tendenz hin zu metallfreien dentalen Versorgungen. Eine zunehmende wissenschaftliche Evidenz belegt deren sichere Verwendung und Wirksamkeit, wenn auch vorerst nur mit kurz- bis mittelfristigen klinischen Studien. Insbesondere im Bereich der Ästhetik aber weisen Keramikimplantate potenzielle Vorteile gegenüber der Versorgung mit Titanimplantaten auf. Dank ihrer zahnähnlichen weißen Farbe führen sie zu einer geringeren Verfärbung der umgebenden Weichgewebe und erlauben so eine ästhetische Versorgung, auch bei einer Mukosadicke von unter 2 mm. Keramikimplantate weisen höhere Pink-Esthetic-Score-Werte auf als zweiteilige Titanimplantate. Basierend auf diesen Daten könnte das Keramikimplantat zukünftig vielleicht als Alternative für den ästhetischen Zahnersatz eingesetzt werden. Zurzeit sind jedoch praktisch keine Langzeitergebnisse aus klinischen Untersuchungen über Keramikimplantate vorhanden. Entwicklungen zur Verbesserung der Verschraubung von zweiteiligen Keramikimplantaten könnten das Anwendungsspektrum erweitern.
Keywords: Zirkoniumdioxidimplantate, vollkeramische Implantate, keramische Abutments, metallfreie Versorgung, Ästhetik, wissenschaftliche Evidenz
The International Journal of Prosthodontics, 2/2019
DOI: 10.11607/ijp.6080, PubMed ID (PMID): 30856641Pages 174-176, Language: English
Purpose: To assess the biologic and technical responses to cemented and screw-retained all-ceramic singletooth implant-supported reconstructions at 3 years postinsertion.
Materials and Methods: Thirty-four patients with single-tooth implants were randomly restored with either a cemented lithium disilicate crown on a customized zirconia abutment (CEM) or a screw-retained crown with a directly veneered zirconia abutment (SCREW). At baseline examination and after 3 years of loading, marginal bone level and technical parameters were assessed. Differences in marginal bone loss were tested using Mann-Whitney U test at baseline and at 3 years, and changes within each group between baseline and 3 years were tested using Wilcoxon signed rank test.
Results: The median changes between baseline and the 3-year follow-up amounted to -0.1 mm (CEM; intragroup P = .36) and -0.0 mm (SCREW; intragroup P = .58). Intergroup comparisons did not reveal statistically significant differences at 3 years (P = .20) or over time (P = .70).
Conclusion: At 3 years, screwretained and cemented reconstructions rendered largely the same radiographic and technical outcomes.
QZ - Quintessenz Zahntechnik, 11/2019
Pages 1452-1455, Language: German