Years Of Functional Loading Research Articles

Ten-Year Follow-Up of Oral Implants in Bone With Limited Bucco-Oral Dimensions: A Prospective Case Series.

It has been suggested that 1-2 mm of bone width at the buccal and lingual aspect is required for a successful long-term implant outcome. Low levels of evidence support this minimum threshold of bone width. This prospective study aimed at evaluating the outcome of implants placed in alveolar ridges with limited bucco-oral dimensions. One-hundred implants (dia. 3.5 mm) were placed in 28 patients with narrow alveolar ridge dimensions (<4.5 mm width) without augmentation procedures and conventionally loaded. Intra-oral radiographs were taken at implant placement and abutment connection and at 1, 2, 3, 5 and 10 years of follow-up. At the 10-year follow-up (21 patients; 75 implants), full-mouth periodontal charting was performed, and the peri-implant keratinized tissue width and attachment type were recorded. Two calibrated periodontists analysed the peri-implant bone changes. After 10 years, all implants showed successful osseointegration and a cumulative survival rate of 100%. The implants were placed 0.85 mm ± 0.89 mm subcrestally. After 10 years, the marginal bone was located 1.59 ± 2.11 mm apical to the implant shoulder. Throughout this period of follow-up, the mean annual marginal bone loss was 0.094 mm. Furthermore, 84% of implants in 72% of patients presented with bleeding on probing. After 10 years of functional loading, implants placed in alveolar ridges with limited bucco-oral dimensions (≤4.5 mm) exhibited only minimum marginal bone loss.

Influence of gingival phenotype on crestal bone loss at implants

PurposeThe aim of this long-term cohort study in periodontally compromised patients with implants was to analyze the correlation between gingival phenotype and peri-implant crestal bone loss, and between clinical measures and gingival phenotype.MethodsImplant-supported single crowns and bridges were used to rehabilitate 162 implants in 57 patients. Patients were examined over a 2 to 20-year period on a recall schedule of 3 to 6 months. In addition to recording clinical parameters, intraoral radiographs were taken at baseline (immediately after superstructure insertion) and at 1, 3, 5, 10, 15, and 20 years. Patients were differentiated into phenotype 1 with thin, scalloped gingiva and narrow attached gingiva (n = 19), phenotype 2 with thick, flat gingiva and wide attached gingiva (n = 23), or phenotyp 3 with thick, scalloped gingiva and narrow attached gingiva (n = 15).ResultsThe mean peri-implant crestal bone loss during the first 12 months was 1.3 ± 0.7 mm. Patients with gingival phenotype 1 had a significantly greater rate of increased crestal bone loss at implants (p = 0.016). No significant differences were present in subsequent years. The prevalence of mucositis at all implants was 27.2%, and the prevalence of peri-implantitis 9.3%. Univariate analyses indicated a significantly higher peri-implantitis risk in patients with gingival phenotype 2 (p-OR = 0.001; p-OR = 0.020). The implants of patients with phenotype 2 had significantly greater probing depths (1st year p < 0.001; 3rd year p = 0.016; 10th year p = 0.027; 15th year p < 0.001). Patients with gingival phenotype 3 showed no significantly increased probing depths, signs of inflammation and crestal bone loss.ConclusionsPatients with a gingival phenotype 1 have greater crestal bone loss at implants during the first year of functional loading. Patients with gingival phenotype 2 had significantly greater probing depth at implants and risk of peri-implantitis.

Manufacturing Accuracy, Intaglio Surface Adaptation, and Survival of Additively and Subtractively Manufactured Definitive Resin Crowns After Cyclic Loading: An In Vitro Study.

To assess the manufacturing accuracy, intaglio surface adaptation, and survival of resin-based CAD/CAM definitive crowns created via additive manufacturing (AM) or subtractive manufacturing (SM). A maxillary right first molar crown was digitally designed and manufactured using AM hybrid resin composite (VarseoSmile Crown Plus, Bego [AM-HRC]), AM glass filler-reinforced resin composite (Crowntec, Saremco Dental [AM-RC]), and SM polymer-infiltrated ceramic (Vita Enamic, VITA Zahnfabrik [SM-PICN]). Manufacturing accuracy (trueness and precision) was assessed by computing the root mean square (RMS) error (in μm; n = 15 per material). Intaglio surface adaptation was assessed by calculating the average gap distance (μm). Ten crowns from each group were cemented on fiberglass-reinforced epoxy resin dies and cyclically loaded to simulate 5 years of functional loading. One-way ANOVA, post hoc Bonferroni comparison tests, and Levene's test were used to analyze the data (α = .05). AM-RC had higher overall trueness than AM-HRC and SM-PICN (P ≤ .05), whereas the trueness of AM-RC on the external surface was similar to that of SM-PICN (P = .99) and higher than AM-HRC (P = .001). SM-PICN had lower precision than AM-RC and AM-HRC overall and at internal occlusal surfaces (P ≤ .05). Overall intaglio surface adaptation was similar between all groups (P = .531). However, for the axial intaglio surface, AM-RC and AM-HRC had higher adaptation than SM-PICN (P ≤ .05). All tested crowns survived the cyclic loading simulation of 5 years clinical use. AM-RC showed high manufacturing accuracy and adaptation. The tested resin-based CAD/CAM materials demonstrated clinically acceptable manufacturing accuracy and simulated medium-term durability, justifying the initiation of clinical investigations to determine their potential implementation in daily clinical practice.

Comparison of values of crestal bone loss around dental implants: A comparative study

Introduction: Many studies have examined values of crestal bone loss according surgical techniques, time of implant placement (immediate post-extraction or after alveolar socket healing), platform switching or convectional platform, surface of the implant, functional loading (immediate or delayed), etc. Methods: This study analyzed a total of 443 dental implants on 115 images: 161 Bredent blueSKY dental implants and 282 Ritter spiral dental implants. All images were taken at the Faculty of Dentistry of the University of Sarajevo: before implantation and after 1 year of functional loading. Crestal bone loss was measured on the mesial and distal side of each implant from the coronal portion of the abutment to the noticeable margin of the alveolar bone. Results: There is statistically significant differences between Bredent blueSKY and Ritter spiral dental implants regarding mesial (p &lt; 0.001, df = 441, tstat = −64.22) and distal (p &lt; 0.001, df = 441, tstat = −151.21) bone losses. Conclusion: Platform switching dental implants showed more bone loss on the mesial and distal side of implant than dental implants with conventional platform.

Effects of cyclic loading on loss of abutment screw torque of angled screw channel single implant crowns on narrow diameter implants

Statement of problemScrew access channels that emerge on the facial aspect of anterior screw-retained implant crowns can compromise esthetics. Recently, angled screw channels (ASCs) have been developed that can alter screw access channel angulations to improve esthetics. While ASCs can be used on narrow-diameter implants, information is limited on the loss of abutment screw torque on narrow-diameter implants with ASCs. PurposeThe purpose of this in vitro study was to compare the loss of abutment screw torque after thermocycling and the cyclic loading of ASCs from 3 different companies connected to narrow-diameter implants. Material and methodsA total of 40 narrow-diameter implants (NobelReplace Conical Connection 3.5×11.5 mm) were mounted individually in acrylic resin blocks and divided equally into 4 groups. The first group, NB-0 (Control), consisted of screw-retained zirconia crowns fabricated on ASCs at 0-degree angulation (n=10). The other 3 groups consisted of a total of 30 screw-retained zirconia crowns fabricated on ASCs at 20-degree angulation: NB-20 (Angulated Screw Channel Solutions), ATL-20 (Atlantis Custom Base Solution with angulated screw access), and DA-20 (Dynamic TiBase). Each crown was secured on the mounted implant with its corresponding titanium base insert and screw and then tightened to the manufacturer’s recommended torque with a digital torque gauge. The initial reverse torque value (RTVI) was obtained and recorded at baseline. Subsequently, a new set of screws were tightened to recommended values, and each specimen underwent thermocycling and then cyclic loading at 0 to 100 N at 10 Hz for 1 million cycles to simulate 1year of functional loading. After cyclic loading, the final reverse torque values (RTVF) were recorded and compared with the RTVI to evaluate the percentage torque loss (PTLF). Statistical analysis was performed using the Kruskal-Wallis analysis, Rank base analysis of covariance (ANCOVA), and the Tukey HSD post hoc comparisons (α=.05). ResultsSignificant differences were found for the PTLF among all groups after cyclic loading (P<.001). The PTLF in ATL-20 (51.4%) was significantly higher than in NB-0 (22.2%) (P<.001) and NB-20 (29.2%) (P=.010). No significant difference was found in the PTLF among other groups (P>.05). ConclusionsThe abutment screw torque loss after cyclic loading of the ASCs on narrow diameter implants among the 4 groups did not perform comparably. The largest percentage torque loss was recorded for the ATL-20 group. The NB-20 group demonstrated the lowest percentage torque loss. DA-20 showed percentage torque loss less than ATL-20; however, its RTVF was the lowest.

Clinical and radiographic results of crestal vs. subcrestal placement of implants in posterior areas: A split-mouth randomized controlled clinical trial.

The objective of this study was to evaluate the peri-implant soft tissue and marginal bone loss (MBL) around implants with platform-switching and internal conical connection placed at crestal and subcrestal levels in posterior areas. Nineteen partially edentulous patients with at least two adjacent missing teeth in posterior areas unilaterally or bilaterally were included. Forty-two implants were placed randomly at the crestal or subcrestal (1 mm) level in a split-mouth design. Implant-supported fixed dental prostheses with screw retention were delivered after 4 months of healing. Clinical and radiological measurements were performed at implant placement (T0), restoration delivery (T1), and 1-year follow-up after loading (T2). MBL was calculated as the change in distance from the implant-abutment interface to the first radiographically visible bone-implant contact. A repeated-measures mixed ANOVA followed by a paired Student's t-test with the Bonferroni correction was used for statistical analysis. p < 0.05 was considered statistically significant. Eighteen patients with thirty-eight implants completed the study at T2. The MBL was lower in the subcrestal group than in the crestal group (0.04 ± 0.08 vs. 0.17 ± 0.17 mm, p = 0.004). The peri-implant probing depth (PD) was 2.31 ± 0.48 mm in the subcrestal group and 1.92 ± 0.43 mm in the crestal group; this difference was statistically significant (p = 0.002). Intragroup comparison showed no significant differences in MBL, or PD around the crestal group and subcrestal group from T1 to T2. After 1 year of functional loading, subcrestal placement of implants with platform-switching and internal conical connection showed lower MBL and was associated with greater PD and peri-implant soft tissue height than implants placed at the crestal level.

Same-Day Digital Dentistry Restorative Workflow for Single Immediate Provisionalization of Narrow-Diameter Implants: An Exploratory Prospective Study

This study evaluated the two-year clinical outcomes of 3.1 mm diameter dental implants, immediately provisionalized and later restored using same-day dentistry, in 10 patients receiving 11 narrow-diameter (3.1 mm) single implants. Each implant was placed and immediately restored with a provisional crown after placement. At least 2 months after placement, the implant was restored with a prefabricated titanium abutment and an all-ceramic crown using a same-day dentistry protocol. Clinical outcomes, including apical bone loss, probing depths, gingival index, and surgical and prosthetic complications, were documented. There was no implant failure over the course of two years. No surgical complications were reported. Two cases lost provisional crowns. One crown needed to be remade due to esthetic concern. The cumulative two-year survival rate of the implants was 100%. Implant bone loss after two years of functional loading was −0.56 ± 0.54 mm and −0.32 ± 0.68 mm for mesial and distal crestal bone, respectively. Two prosthetic complications included recementation of a crown and remaking of a crown. This exploratory study suggests that immediate provisionalization and a same-day restorative dentistry digital workflow protocol for narrow-diameter implants appear to be predictable clinical procedures with no reported surgical complications and minimal prosthetic complications.

Long-Term Clinical and Radiographic Analysis of Platform Matching and Platform Switching Implants in the Esthetic Zone: A Retrospective Cohort Study

Background: The aims of this study are to retrospectively compare the clinical, radiographic and esthetic outcomes of platform switching (PS) and platform matching (PM) dental implants in the anterior maxilla after ≥ 10 years of functional loading. Methods: Marginal bone loss (MBL) levels were recorded; furthermore, peri-implant clinical parameters (PPD, BOP, PI) were collected and the Pink and White Esthetic scores (PES/WES) were used to evaluate the esthetic outcomes. Wilcoxon signed rank tests were performed to compare collected parameters among the two groups, with a p-value &lt; 0.05. Results: A final sample of 58 patients was enrolled in this study (PM implants = 29; PS implants = 29). PS implants showed lower MBL levels (1.02 ± 0.81 mm vs. 1.67 ± 0.99 mm, p = 0.028) and PPD values (3.69 ± 1.1 vs. 5.16 ± 1.09 mm, p &lt; 0.001) compared to PM implants. Mean PES values were higher in the PS group compared to the PM group (8.46 ± 0.69 vs. 7.89 ± 0.78, p &lt; 0.005), while there were no differences for WES values (7.82 ± 1.09 vs. 7.71 ± 0.85, p &gt; 0.05) and peri-implant diseases’ prevalence (p &gt; 0.05). Conclusions: After 10 years, PS implants showed statistically significant lower MBL and PPD values and higher PES values compared to PM implants.

Does a Severely Resorbed Subantral Ridge Decrease Long-Term Implant Survival Rate with Sinus Floor Augmentation?

To identify the impact of residual bone height on 5-year implant survival and prosthetic complication rates in patients who underwent maxillary sinus grafting. A total of 87 consecutive patients were treated with 104 lateral approach maxillary sinus floor augmentation procedures with 100% deproteinized bovine bone and received 169 implants. The analysis considered patient age, sex, time of implant placement, and residual bone height. Patients with < 3 mm residual bone height were assigned to the study group; otherwise, they were placed in the control group. The mean follow-up was 68.2 months (0 to 103 months). The mean residual bone height was 1.8 mm in the study group and 4.1 mm in the control group. The 5-year implant survival and prosthetic complication rates were, respectively, 97.4% and 8.0% in the study group and 100% and 12.5% in the control group. Residual bone height, sex, age, and time of implant placement were not significant factors for the 5-year implant survival or prosthetic complication rate. The lateral bone wall was significantly thinner in the study group. The grafted bone height reduction was significantly different at 6 months and 2 years postoperation in both groups, but there was no difference in the change in grafted bone height reduction over time between the two groups. A residual bone height < 3 mm did not impact the survival rates of implants placed in grafted maxillary sinuses or the prosthetic complication rate after 5 years of functional loading.

Clinical and radiographic outcomes of dental implant after maxillary sinus floor augmentation with rhBMP-2/hydroxyapatite compared to deproteinized bovine bone.

ObjectivesThis study aimed to evaluate the clinical and radiographic outcomes of early implant placement and functional loading in maxillary sinus floor augmentation (MSFA) using recombinant human bone morphogenetic protein 2/hydroxyapatite (rhBMP-2/HA) and to compare these outcomes with those of the conventional protocol in MSFA using deproteinized bovine bone (DBB).Materials and methodsThe rhBMP-2/HA and DBB groups consisted of 14 and 13 patients who underwent MSFA with BMP and DBB, respectively. After placement of 22 implants and 21 implants in the rhBMP-2/HA and DBB groups, respectively, abutment connections were performed 3 months after implant placement for the rhBMP-2/HA group and 6 months after implant placement for the DBB group. Changes in grafted sinus height (GSH), marginal bone loss (MBL), and implant stability were evaluated up to one year after functional loading.ResultsSurvival rates for the rhBMP-2/HA and DBB groups after one year of functional loading were 90.9% and 90.5%, respectively. Both groups exhibited no significant time-course changes in GSH until one year of functional loading (rhBMP-2/HA, p = 0.124; DBB, p = 0.075). Although significant MBL occurred after one year of functional loading for both groups (rhBMP-2/HA, p < 0.001; DBB, p < 0.001), there were no significant differences in time-course changes in MBL between the two groups (p = 0.450). The mean implant stability quotient values in the rhBMP-2/HA and DBB groups were 75.3 and 75.4 after one year of functional loading, respectively, and there were no significant differences between the two groups (p = 0.557).ConclusionsMSFA using rhBMP-2/HA allowed implant rehabilitation with early implant placement and functional loading and led to a comparable survival rate and implant stability after 1 year of functional loading with acceptable MBL and stable maintenance of GSH compared to the MSFA using DBB with 6 months of healing after implant placement.

Peri-Implant Marginal Bone Changes around Dental Implants with Platform-Switched and Platform-Matched Abutments: A Retrospective 5-Year Radiographic Evaluation.

Preserving the marginal bone level (MBL) is essential for the long-term success of dental implant therapy, and bone remodeling around dental implants is considered to vary with time. Numerous studies comparing the platform-switching (PS) and platform-matching (PM) dental implants have indicated that PS dental implants showed a lesser reduction for the MBL, and the majority of them had a relatively short period. This study aimed to evaluate vertical and horizontal bone defects by using digital periapical radiographs to examine the changes in MBL around PM and PS dental implants over 5 years after functional loading. The vertical MBL (vMBL) was measured from the implant–abutment junction to the first bone-to-implant contact. The horizontal MBL (hMBL) was measured from the implant–abutment junction to the bone crest. All data were presented as means ± standard errors. Paired and independent t-tests with Welch’s correction were used to analyze the data. A total of 61 dental implants in 38 patients after 5 years of functional loading were evaluated. Over time, PS dental implants were more likely to gain bone; by contrast, PM dental implants were more likely to lose bone during the observation time. Changes in vMBL for PS dental implants were significantly less than those for PM dental implants at 1-year (p = 0.045), 3-year (p = 0.021), and 5-year (p = 0.010) loading. Likewise, changes in hMBL for PS dental implants were significantly smaller than in those for PM dental implants at 3-year (p = 0.021) and 5-year (p = 0.006) loading; however, the changes were minimal in both approaches. PS dental implants had a significant increment in the percentage of bone integration, whereas that for PM dental implants dropped over time, with no significance. In PS dental implants that occlude with natural teeth, vertical and horizontal bone gain was observed, and it was significant at 3 years (p = 0.023). A significant horizontal bone gain was observed in the opposing natural teeth at 3-year (p = 0.002) and 5-year loading (p = 0.002). The PS concept appears to preserve more MBL around dental implants by stabilizing the vMBL and hMBL over a 5-year period. A minimal marginal bone change was detected in both concepts. The opposing natural teeth at PS dental implants showed a favorable effect on marginal bone tissues.

What Does Bone Corticalization around Dental Implants Mean in Light of Ten Years of Follow-Up?

The phenomenon of peri-implant bone corticalization after functional loading does not yet have a definite clinical significance and impact on prognosis. An attempt was made to assess the clinical significance of this phenomenon. This prospective study included 554 patients. Standardized intraoral radiographs documenting the jawbone environment of 1556 implants were collected. The follow-up period was 10 years of functional loading. Marginal alveolar bone loss (MBL) and radiographic bone structure (bone index, BI) were evaluated in relation to intraosseous implant design features and prosthetic work performed. After five years, bone structure abnormalities expressed by a reduction of BI to 0.47 ± 0.21 and MBL = 0.88 ± 1.27 mm were observed. Both values had an inverse relationship with each other (p < 0.0001). Reference cancellous bone showed BI = 0.85 ± 0.18. The same relationship was observed after ten years of functional loading: BI = 0.48 ± 0.21, MBL = 1.49 ± 1.94 mm, and again an inverse relationship (p < 0.0001). Increasing corticalization (lower BI) is strongly associated with increasing marginal bone loss and increasing corticalization precedes future marginal bone loss. Marginal bone loss will increase as corticalization progresses.

Immediate, non-submerged, three-dimensionally printed, one-piece mandibular molar porous root-analogue titanium implants: A 2-year prospective study involving 18 patients

This study prospectively evaluated non-submerged, three-dimensionally printed, one-piece molar porous root-analogue titanium implants. A total of 18 non-restorable multiple-rooted teeth in 18 patients, aged 22–64 years, were included in this study. A series of computed tomography images of the mandible were selected and rendered into a digital model. The non-restorable mandibular molars were digitally separated from the surrounding alveolar bone, and served as the template on which the porous root-analogue titanium implants (RAIs) were designed with computer-aided design (CAD) software. The porous molar RAIs were fabricated with the selective laser melting technique (average particle size 20 μm) and inserted into the alveolar sockets after extraction of the non-restorable molars. Definitive restorations were placed after 3 months of uninterrupted healing. Peri-implant clinical and radiographic measurements were obtained 2 years later. All patients functioned well following 2 years of functional loading, and peri-implant clinical and radiographic measurements demonstrated implant stability. No implants were lost at the 2-year follow-up, and the survival rate was 100%. Three-dimensionally printed one-piece molar porous RAIs may be a promising option for the replacement of non-restorable molars that are planned for extraction. Additional studies are required to evaluate the long-term survival of implants fabricated using this technique.

Long-Term Outcomes of Implants Placed in Maxillary Sinus Floor Augmentation with Porous Fluorohydroxyapatite (Algipore® FRIOS®) in Comparison with Anorganic Bovine Bone (Bio-Oss®) and Platelet Rich Plasma (PRP): A Retrospective Study.

Purpose: The objective of this retrospective study was to evaluate the long-term clinical outcomes of bone regeneration procedures using algae-derived plant hydroxyapatite (Algipore® FRIOS®) compared with demineralized anorganic bovine bone (Bio-Oss®), in combination with autologous blood-derived PRP. Materials and Methods: Partially edentulous patients with severe atrophy of posterior maxillary treated by means of the split bone technique in a two-stage grafting procedures were observed for up to seven years after implants placement. After surgeries, the natural porous fluorohydroxyapatite (FHA) (Algipore® FRIOS®; Group, n = 29) or anorganic bovine bone (Bio-Oss® Group, n = 28) with autogenous bone in a 50:50 composite ratio with PRP, were administered in a 2.8-mm critical-size defect (CSD). Four months later, implants were placed at second-stage surgery. Results: A sample of fifty-seven consecutive patients who required sinus augmentation was included in the study, and 57 implants were placed. There was no drop out or loss of follow-up of any case. Clinical and radiographic examinations revealed a comparable pattern of newly formed bone in both groups after seven years of functional loading for implants placed after sinus augmentation using porous fluorohydroxyapatite and anorganic bovine bone. No significant difference in marginal bone loss was found around implants in both groups. Conclusions: The favorable implant outcomes suggest both biomaterials are suitable for sinus grafting in severely atrophic maxillae.

Bone remodeling around dental implants after 1-1.5 years of functional loading: A retrospective analysis of two-stage implants.

ObjectivesThis study aims to retrospectively assess to what extent peri‐implant bone level changes occur from exposing the implant to the oral environment at the second stage of surgery (SSS) to the baseline assessment and, additionally, after 1–1.5 years of functional loading. Further, this study aims to examine the role of the emergence angle in marginal bone changes.Material and MethodsThis retrospective study included 46 patients treated between 2012 and 2019. These patients received 64 bone‐level dental implants. After implant placement, SSS, and baseline assessment, relevant clinical peri‐implant conditions and radiographical data were collected. A radiographic examination of the marginal bone level was performed after SSS, the baseline assessment, and 1–1.5 years of follow‐up.ResultsThe peri‐implant periodontal probing depth increased significantly from 3.08 ± 0.7 mm at the baseline to 3.27 ± 0.81 mm at the 1–1.5‐year follow‐up. The mean marginal bone level at the implant level was 0.12 ± 0.23, 0.35 ± 0.43, and 0.47 ± 0.47 mm at the SSS, baseline, and the 1–1.5‐year follow‐up, respectively. Most changes occurred at the implant's distal site. A significant relationship was found between the emergence angle and the extent of change in the marginal bone level between the SSS and baseline (r = .430, p ≤ .001).ConclusionsMost changes in the marginal bone level occurred between SSS and baseline assessments. For diagnostic purposes, it is advised to obtain a standardized radiograph after SSS to monitor peri‐implant bone‐level alterations.

Computer-assisted implant placement and full-arch immediate loading with digitally prefabricated provisional prostheses without cast: a prospective pilot cohort study

BackgroundImmediate loading of implant-supported full-arch rehabilitations has become routine practice when treating edentulous patients. The combination of static computer-aided implant surgery (s-CAIS) and digital prosthetic workflow could eliminate several treatment steps and facilitate prostheses delivery.The aim of this study is to evaluate the 1-year results of digitally prefabricated polymethyl methacrylate (PMMA) provisional prostheses without a cast for full-arch computer-assisted immediate loading.Materials and methodsA digital pre-operative treatment planning was realized for all patients: dental implants and screw-retained abutments were selected in the planning software and two surgical templates were fabricated for each patient. The first template was mucosa or teeth-supported to drill the holes for fixating pins, while the second template was placed after raising a full-thickness flap and was supported by pins as well as soft or hard tissue distal support. Furthermore, based on the surgical planning, interim prostheses were digitally designed and milled of PMMA resin blocks with subsequent pink resin veneering. Osteotomies and implant placement were performed through the surgical guides and all implants were immediately loaded with prefabricated full-arch interim prostheses directly connected to titanium copings with a flowable resin.ResultsA total of 55 dental implants were placed in ten patients. In all cases, interim prostheses allowed the insertion of titanium copings without the need of access hole enlargement or adaptation. All the prostheses had 1 year of functional loading to simulate the long provisional phase. No screw loosening occurred at the first removal of the prostheses after implant osseointegration. No fracture occurred during the whole period. After 1 year, the mean marginal bone loss level was 0.37 ± 0.06 mm, while the implant survival rate was 98.18% (n=54/55), with just one implant failing but not affecting final prosthesis delivery to the patient.ConclusionsWithin the limitations of the present study, the authors concluded that digitally prefabricated provisional prostheses for full-arch immediate loading with s-CAIS could be a valid alternative treatment modality. Milled PMMA restorations proved to be durable enough during the long provisional phase, without prosthetic complications.

Octacalcium Phosphate Bone Substitute (Bontree®): From Basic Research to Clinical Case Study

Bone grafts used in alveolar bone regeneration can be categorized into autografts, allografts, xenografts, and synthetic bones, depending on their origin. The purpose of this study was to evaluate the effect of a commercialized octacalcium phosphate (OCP)-based synthetic bone substitute material (Bontree®) in vitro, in vivo, and in clinical cases. Material characterization of Bontree® granules (0.5 mm and 1.0 mm) using scanning electron microscopy and X-ray diffraction showed that both 0.5 mm and 1.0 mm Bontree® granules were uniformly composed mainly of OCP. The receptor activator of NF-κB ligand (RANKL) and alkaline phosphatase (ALP) activities of MG63 cells were assessed and used to compare Bontree® with a commercial biphasic calcium phosphate ceramic (MBCP+TM). Compared with MBCP+TM, Bontree® suppressed RANKL and increased ALP activity. A rabbit tibia model used to examine the effects of granule size of Bontree® grafts showed that 1.0 mm Bontree® granules had a higher new bone formation ability than 0.5 mm Bontree® granules. Three clinical cases using Bontree® for ridge or sinus augmentation are described. All eight implants in the three patients showed a 100% success rate after 1 year of functional loading. This basic research and clinical application demonstrated the safety and efficacy of Bontree® for bone regeneration.

Single-crown restorations supported by short implants (6 mm) compared with standard-length implants (13 mm) in conjunction with maxillary sinus floor augmentation: a randomized, controlled clinical trial

BackgroundThe purpose of the present study was to test the H0-hypothesis of no difference in the clinical and radiographical treatment outcome of single-crown restorations supported by short implants compared with standard length implants in conjunction with maxillary sinus floor augmentation (MSFA) after 1 year of functional implant loading. Forty patients with partial edentulism in the posterior part of the maxilla were randomly allocated to treatment involving single-crown restorations supported by short implants or standard length implants in conjunction with MSFA. Clinical and radiographical evaluation were used to assess survival of suprastructures and implants, peri-implant marginal bone loss (PIMBL), biological, and mechanical complications.ResultsBoth treatment modalities were characterized by 100% survival of suprastructures and implants after 1 year. Mean PIMBL was 0.60 mm with short implants compared with 0.51 mm with standard length implants after 1 year of functional loading. There were no statistically significant differences in survival of suprastructure and implants, PIMBL, and mechanical complications between the two treatment modalities. However, a higher incidence of biological complications was associated with standard length implants in conjunction with MSFA.ConclusionWithin the limitations of the present study, it can be concluded that single-crown restorations supported by short implants seems to be comparable with standard length implants in conjunction with MSFA. However, long-term studies are needed before final conclusions can be provided about the two treatment modalities.Trial registrationClinicaltrials.Gov ID: NCT04518020. Date of registration: August 14, 2020, retrospectively registered.

Peri-Implant Behavior of Tissue Level Dental Implants with a Convergent Neck.

Introduction: The aim of this retrospective study was to analyze the radiographic peri-implant bone loss of bone level implants and tissue level implants with a convergent neck in screw-retained single crowns and in screw-retained fixed partial prostheses, after two years of functional loading. Materials and methods: The sample was divided into two groups according to their type: Group I: supracrestal implants with convergent transmucosal neck; Group II: crestal implants. In each group we distinguish two subgroups according to the type of prosthetic restoration: single crowns and a three-piece fixed partial prosthesis on two implants. To quantify bone loss, parallelized periapical radiographs were analyzed at the time of implant placement and after two years of functional load. Results: A total of 120 implants were placed in 53 patients. After statistical analysis it was observed that for each type of implant bone loss was 0.97 ± 0.91 mm for bone level and 0.31 ± 0.48 mm for tissue level. No significant differences were found regarding the type of prosthesis and the location (maxilla or mandible) of the implants. Conclusions: Tissue level implants with a convergent transepithelial neck exhibit less peri-implant bone loss than bone level implants regardless of the type of prosthesis.

Microbial communities of titanium versus zirconia abutments on implant-supported restorations: Biodiversity composition and its impact on clinical parameters over a 3-year longitudinal prospective study.

Shifts in microbial communities are common over time, but they may disturb the host-microbiome homeostasis and result in inflammation of the peri-implant issues if a dysbiotic biofilm is established. Considering that different oral substrate surfaces may have a relevant impact on the microbial adhesion and colonization, the aim of this study was to investigate the microbial communities of the biofilm formed on single-implant restorations using titanium or zirconia abutments and how they correlate with clinical parameters after 3-years of implant loading. MiSeq sequencing of 16S rRNA amplicons was used to characterize the oral biofilms of individuals (n = 20) who were sampled longitudinally during 3 years of masticatory loading. Bioinformatics analysis and multivariate statistical analysis were used to evaluate the microbial diversity and clinical outcomes. Microbiomes of both abutment materials presented high alpha-diversity indices during all the experimental period, irrespective of the time of sampling. Microbial communities of titanium and zirconia were quite different over time, differing about 30% after 3 years of functional loading. Similarity of microbiomes between tested abutments and contralateral teeth was also low, ranging between 45% and 50% after 3 years of investigation. Periodontal pathogens commonly associated with peri-implantitis were found in both groups. Furthermore, both abutment materials presented strong correlations of diversity indices and microbial taxa with clinical outcomes. The type of abutment substrate significantly influenced diversity and clustering of communities during 3 years of functional loading. The time of sampling had no effect on the variables. Large correlations were found between microbial findings and clinical outcomes.