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Multiple disconnection and reconnection of abutments has been known to affect the mucosal barrier around implants, leading to marginal bone loss (MBL). This clinical report describes a novel technique that amalgamates the benefits of digital technologies including the fabrication of surgical guides for implant placement, customized hybrid zirconia abutments, and all-ceramic lithium disilicate crowns prior to implant placement. Correct 3D implant positioning, along with immediate placement of the definitive hybrid customized abutment and a lithium disilicate crown, have the potential to reduce treatment time, visits, and costs while delivering optimal esthetic outcomes. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the response of human peri-implant soft tissue (PIST) to different healing abutment materials 24 hours after positioning by assessing the expression of genes related to the early connective tissue wound healing response. Materials and Methods: The following four materials were used to create experimental abutments that were mounted on implants placed in five patients (four different abutments in each patient): group A--grade 4 titanium (Ti), group B--grade 5 Ti, group C--zirconia (Zr), and group D--polyetheretherketone (PEEK). Before implant placement, a gingival biopsy (control, CT) sample was obtained using a 2-mm-diameter punch (T0). After 24 hours, PIST biopsy samples were collected using a specifically designed custom-made cutting device. Real-time polymerase chain reaction (PCR) was performed to analyze the expression of the following genes: COL-I, COL-III, MMP-1, TIMP-1, TGF-^1, FN, ITGA4, ITGA5, ITGB1, RAC-1, COL-IV, aSMA, IL-6, and CXCL-1. Results: Gene expression analysis showed some differences between CT and the experimental groups; however, no significant differences were detected when comparing the experimental groups. COL-I was significantly downregulated in groups A and C compared to CT. Expression of MMP-1 and TIMP-1 increased in all the experimental groups but to a lesser extent in group A. FN, RAC-1, COL-IV, and aSMA were downregulated, especially in group A, in which CXCL-1 and IL-6 showed the lowest expression. Conclusions:The results of grade 4 Ti and Zr abutments seem to be promising, because a lower expression of genes related to inflammation, myofibroblast activation, and extracellular matrix remodeling was observed when compared with grade 5 Ti and PEEK, without triggering a profibrotic response in the early phases of PIST repair. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate over 5 years the mesial, distal, palatal, and buccal bone levels as well as the buccal bone thickness surrounding scalloped implants that were immediately placed and loaded with provisional crowns fixed on final prefabricated abutments. Materials and Methods: A total of 18 implants were placed and immediately loaded using CAD/CAM technology in 18 patients to replace a single tooth in the anterior maxilla. The marginal bone levels around the scalloped implant necks were measured mesially and distally using intraoral standardized radiographs after crown placement as well as at the 1-, 3-, and 5-year follow-ups. CBCT para-axial cut images were used to measure the bone level buccally and palatally from the implant neck to the bone-to-implant contact (BIC) 5 years after loading. These images were used to evaluate the thickness of the buccal bone at the implant neck and 4 mm apically both immediately after implant placement (T0) and 5 years later. Results: All implants were assessed clinically and radiologically after 5 years. No implant failure was recorded, and the average marginal bone variation for mesial and distal sites was as follows: 0.114 ± 0.135 mm at crown cementation, 0.239 ± 0.158 mm 1 year later, 0.233 ± 0.182 mm 3 years later, and 0.180 ± 0.182 mm 5 years later. Our findings indicate that at T0, the average thickness of the buccal bone was 2.27 mm at the implant neck (M0; ranging from 1.9 to 2.4 mm) and 2.33 mm at 4 mm apical to the implant neck (M1; ranging from 1.9 to 2.9 mm). At 5 years postoperative (T4), the mean had decreased to 1.94 mm at M0 (ranging from 1.7 to 2.3 mm) and 2.14 mm at M1 (ranging from 1.8 to 2.4 mm). After 5 years of functional loading, the mean changes at the buccal and palatal bone for all implants were +0.187 ± 0.52 mm and +0.06 ± 0.38 mm, respectively. Minor prosthetic problems were observed over the 5 years, including incisal ceramic chipping in two crowns and replacement of two crowns due to esthetic reasons after 1 year. No loosening of crowns or abutments was reported. Conclusions: Scalloped-neck implants demonstrated a comparable behavior to regular-neck implants with similar designs in immediate placement and temporization protocol over a 5-year period. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the clinical performance of implant-prosthetic rehabilitations carried out using ceramic-coated CAD/ CAM titanium abutments. Materials and Methods: Thirty implants were placed in 30 patients and rehabilitated with 30 single crowns attached to CAD/CAM titanium abutments. A conventional procedure was applied, implants were placed after postextraction socket healing, and prosthetic restorations were placed after implant healing. Implant lengths ranged from 6 to 15 mm, and widths were 3.6, 4.2, and 4.8 mm. At the time of prosthesis delivery (T0), after 2 years (T1), and after 5 years (T2), the Plaque Index (PI), bleeding on probing (BoP), pocket probing depth (PPD), marginal bone level (MBL), and pink/white esthetic scores (PES/WES) were evaluated for each implant. Results: No patient dropped out of the study during the follow-up period. All 30 implants were clinically successful 5 years after prosthesis delivery (survival rate: 100%) and showed no signs of peri-implant infection. Peri-implant soft tissues were in good health (BoP at T2: 0% in 73% of patients; 25% in 13% of patients; 50% in 10% of patients; and 75% in 3% of patients). The mean PPD was 2.05 ± 0.56 mm at T0, 1.992 ± 0.6 mm at T1, and 1.867 ± 0.439 mm at T2. The mean MBL was 0.413 ± 0.440 mm at T0, 0.306 ± 0.388 mm at T1, and 0.263 ± 0.368 mm at T2. The mean PES, WES, and PES/WES indices (7.43 ± 1.04, 7.57 ± 0.82, and 15.00 ± 1.17, respectively) indicate good integration of soft tissues, satisfactory esthetics, and overall positive outcomes. Conclusions: The success rates, maintenance of MBLs, and periodontal and esthetic indices suggest the validity of implant-prosthetic rehabilitations with CAD/CAM abutments in cases of single crowns. [ABSTRACT FROM AUTHOR]

Purpose: To identify the technical complications associated with maxillary complete-arch implant-supported fixed prostheses (ISFPs) and to evaluate the survival rates of both dental implants and prostheses. In addition, we sought to analyze the impact that the presence of cantilevers, the type of prosthetic abutment, and the number of implants have on the occurrence of complications. Materials and Methods: Data were obtained from standardized clinical assessments carried out in a single appointment by two calibrated professionals (F.B.A. and I.A.Y.) using information from dental records. Results: The sample consisted of 64 patients rehabilitated with ISFPs classified as hybrid prostheses (metal-resin). The survival rate for implants was 98.6% after 1 to 12 years (5.2 years ± 36.6 months) and was 100% for the prostheses after a follow-up of 12 to 144 months (mean: 48.1 ± 33.94 months). The most frequent complications were occlusal wear (82.8% of patients) as well as loosening of prosthetic screws (16.6%) and abutments (8.1%). The screw loosening frequency was significantly greater in 30-degree abutments compared with straight abutments (P = .008), but no significant difference was found between 17-degree and 30-degree abutments. Prostheses with a higher occurrence of screw loosening had a greater average cantilever length/anteroposterior spread (CL/AP) ratio (0.9 ± 0.5). In addition, abutments placed on distal implants were more likely to loosen (P < .001). The absence of mutually protected occlusion did not significantly influence the loosening of prosthetic screws and abutments. Conclusions: Implant-supported fixed maxillary complete-arch rehabilitations have high survival rates but are subject to technical complications. [ABSTRACT FROM AUTHOR]

Purpose: To conduct a systematic review and meta-analysis to examine the impact of titanium (Ti) base-supported single-implant restorations on peri-implant conditions. Materials and Methods: Six randomized controlled trials (RCTs) comprising 274 implants met the inclusion criteria and were chosen for data analysis. A random-effects model was employed for the meta-analysis. Results: Data from this study revealed that the Ti-base group exhibited a small but statistically significant increase in peri-implant marginal bone loss (MBL; mean difference = 0.088 mm; 95% CI = 0.003 to 0.17; P = .041) compared to the one-piece abutment group. These effects were consistent in the subgroup analysis of regularly threaded implants compared to the microthreaded subgroup. No significant differences were observed between the Ti-base group and the abutment group concerning probing depth (PD), bleeding on probing (BoP), and the risk of prosthetic-related complications. Conclusions: The use of a Ti-base in a single implant-supported restoration is associated with a slight increase in peri-implant MBL, while other peri-implant health parameters show no significant correlation. Therefore, the evidence of the impact that Ti-bases have on the peri-implant conditions of single implant-supported restorations is insufficient based on the findings of the present meta-analysis. [ABSTRACT FROM AUTHOR]

Purpose: To perform a finite element analysis (FEA) and an in vitro experiment to investigate and compare the loading effects (effects on the implant and surrounding bone) of various customized angled abutments to commercial 15-degree angled abutments (control). Materials and Methods: Four customized angled abutment models (21.9, 24.15, 20.22, and 33 degrees) were developed using CBCT images of incisor inclination measurements from patients of various age groups (20 to 23, 24 to 39, and 40 to 65 years). 3D maxillary bone models were created from the CBCT images of four individual patients: One patient from each age group with the respective average incisor inclination measurement and another patient with the overall average were selected. Then, FEA and in vitro strain gauge experiments were conducted by applying 100 N or 50 N of axial or oblique force to each model in order to assess the differences in stress/strain between the customized angled abutments (test) and the control in both the implants and surrounding bone. Results: Under axial loading, the stress values in the implant and surrounding bone were elevated due to the relatively higher angles of the customized angled abutments (21.9, 24.15, 20.22, and 33 degrees) compared to the control angled abutments. Under oblique loading, the control angled abutments exhibited higher stress values in both the implant and surrounding bone. For the in vitro experiment, there was no statistically significant difference in bone strain between the customized (21.9 degree) and the control angled abutments in axial loading. Nevertheless, the control angled abutment with oblique loading induced greater bone strains. Conclusions: Customized angled abutments offer lower stress/strain under oblique loads but higher stress/strain under axial loads compared to the control abutments. Therefore, in the design and application of angled abutments, careful consideration of the occlusal load direction is important for achieving the biomechanical success of an implant. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the rotational load fatigue performance of different implant diameters and abutment platforms of a one-size implant-abutment (OSIA) connection system. Materials and Methods: Narrow-, regular-, and wide-diameter implants were tested with regular base (RB/WB) abutments of an OSIA system (BLX, Straumann). Wide-diameter implants (WDIs) were also tested with wide base (WB) abutments. This resulted in four test groups: (1) narrow-diameter implants (NDIs; 3.5 mm) with RB/WB abutments, (2) regular-diameter implants (RDIs; 4.0 mm) with RB/WB abutments, (3) WDIs (5.0 mm) with RB/WB abutments, and (4) WDIs (5.0 mm) with WB abutments. Each group tested five of their respective implants (n = 5). A rotational load fatigue machine applied a sinusoidally varying stress at a 45-degree angle, producing an effective bending moment of 35 Ncm at a frequency of 10 Hz in 20°C air. The number of cycles to failure was recorded, and the results were evaluated using two-way ANOVA. Failed specimens were examined with a scanning electron microscope (SEM) to evaluate the failure mode. Pristine specimens were sectioned to examine the implant-abutment connection. Results: All specimens in three of the test groups with RB/WB abutments failed within the range of 558,750 cycles to 4,497,619 cycles, while the WDI-WB test group reached the upper limit of 5 million cycles without failure. A significant difference was found between abutment platforms (P < .001). There were no significant differences found for implant diameters (P = .857). However, with a greater implant diameter, implant fracture was less common, and the failure location was more coronal. It was consistently at the implant platform level for the abutment and at the screw neck. Conclusions: For WDIs, WB abutments exhibited superior fatigue performance compared to RB/WB abutments and would be preferred in situations of high mechanical risk. Increasing the implant diameter, when used with RB/WB abutments, did not improve fatigue performance due to the one-size prosthetic connection; however, failures were less catastrophic and coronally located, which may be advantageous in managing failures. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate clasp-retained removable partial dentures (C-RPDs) with a metal framework for survival, maintenance requirements, and biologic implications. Method and materials: C-RPDs were retrospectively analyzed based on patient records. Treatment failure was defined as fracture of a framework component (metal base or connector) or loss of an abutment tooth. Other outcome variables included factors that might conceivably impact C-RPD survival (maxilla vs mandible, Kennedy classes, opposing dentitions, treatment by students vs certified dental practitioners), mobility and caries of abutment teeth (in relation to clasp designs), and maintenance requirements (relining, clasp or resin fractures). Differences were evaluated by appropriate statistical tests at the P≤.05 level. Results: A total of 612 patients (339 men, 273 women) 60.0±11.5years old at delivery were included, covering 842 C-RPDs and a mean observation period of 42.1±33.2months. Kaplan-Meier C-RPD survival was 76.2% after 5years and 49.5% after 10years. Biologic complications (ie, loss of abutment teeth) accounted for the vast majority (95.6%) of C-RPD failures, and Kaplan-Meier C-RPD survival was significantly better in the mandible (P=.015). Some clasp designs contributed significantly to caries and removal of abutment teeth (both P<.05). No other significant differences were noted. Conclusion: Tooth loss both emerges as the main cause of C-RPD failure and might be amenable to careful selection of clasp designs. Overall, better C-RPD survival should be expected in the mandible. A noncon-tributory role of Kennedy classes and opposing dentitions is tentatively suggested based on numerically heterogenous subgroups. [ABSTRACT FROM AUTHOR]

This study compared the survival, marginal bone loss (MBL), and prosthetic complications of 4.5-mm extra-short implants and longer implants splinted to the short implants via the restoration. A retrospective controlled cohort study was performed. The 4.5-mm extra-short group (study group; SG) included 48 consecutively placed implants. The control group (CG) included 48 implants splinted to the extra-short implants. The same surgical team treated the 39 included patients, and all implants were restored with a screw-retained fixed restoration and intermediate abutments. Immediate and conventionally loaded implants were included. All implants were in function during the follow-up period (14 ± 3.4 and 17 ± 13 months for SG and CG, respectively). No differences in technical complications were observed between the groups (one and two cases of screw loosening for SG and CG, respectively; two provisional prosthesis fractures for SG; P = .310). Marginal bone stability was similar for SG and CG at the mesial level (-0.01 ± 0.28 mm for SG vs -0.18 ± 0.72 mm for CG; P = .270) and at the distal level (0.02 ± 0.39 mm for SG vs -0.18 ± 0.68 mm for CG; P = .076). The same good clinical performance could be observed for 4.5-mm implants and longer implants under the same prosthesis. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the esthetic outcomes based on the color differences in zirconia (Zr) of varying thickness, resin cement color, and types of titanium (Ti) implant surface treatments. Materials and Methods: Overall, 28 high-translucency monolithic zirconia (HTMZ) specimens were arranged into four groups based on Zr thickness: 1.0, 1.5, 2.0, and 2.5 mm (n = 7 per thickness). Each group was tested using two resin cement colors (clear and opaque) in combination with six surface-treated Ti groups (n = 7), including untreated titanium (UT), anodization (AN), 50-µm alumina airborne-particle abrasion followed by AN (SBAN), AN followed by 50-µm alumina airborne-particle abrasion (ANSB), 9.5% hydrofluoric acid followed by AN (HFAN), and AN followed by 9.5% hydrofluoric acid (ANHF). This created a total of 48 experimental groups, including the use of composite resin (n = 7, shade A2D) for four control groups. All specimens were measured using a spectrophotometer and subsequently compared with composite resin (control) with the corresponding Zr thickness to establish color differences. A color difference of < 2.7 was considered clinically acceptable. The data obtained were statistically analyzed using ANOVA and post hoc test (P = .05). Results: Zr thickness, resin cement color, and type of Ti implant surface treatment significantly affected the observed color differences (P < .05). When using 2.5-mm HTMZ with clear resin cement on AN, UT, SBAN, HFAN, and ANSB, the mean color differences were below the clinically acceptable values, and the 95% CIs of color differences were below the clinically acceptable values for AN, UT, and SBAN groups. Conclusions: HTMZ with a minimum thickness of 2.5 mm and clear resin cement on AN, UT, and SBAN groups potentially result in acceptable color matching with 95% CIs. [ABSTRACT FROM AUTHOR]

Purpose: To develop the most compatible cementation protocol for ensuring minimal residual cement and optimal retention of cement-retained implant-supported fixed dental prostheses. Materials and Methods: A total of 30 custom implant abutments and zirconia crowns with bilateral wings were prepared. Three cement types were used for cementation: noneugenol resin cement (Premier Implant Cement; Group IC), dual-polymerizing self-adhesive resin cement (SmartCem2; Group SC), and zinc oxide eugenol cement (Temp-Bond; Group TB; n = 30 per group). Three cementation methods were applied for each cement type, and the samples were divided into subgroups: (1) cement was injected using a graduated syringe (ICN, SC-N, and TB-N); (2) a cementation jig made with a silicone impression material and temporary resin material was used (IC-CJ, SC-CJ, and TB-CJ); (3) 3D-printed abutments were used as replicas for cementation (IC-3DP, SC-3DP, and TB-3DP). The amount of cement injected, surface area of the residual cement, and retentive strength were measured. Kruskal-Wallis and post-hoc Mann-Whitney tests were used for statistical analyses. Results: Excess cement was not observed when cementation jig or 3D-printed replicas were used. For IC and SC subgroups, non-use of these auxiliary tools resulted in significantly higher amounts of injected cement. The retentive strength differed significantly among the IC subgroups but not among the SC subgroups. The retentive strength of subgroups TB-N and TB-CJ was significantly higher than that of subgroup TB-3DP. Conclusions: To prolong the main purpose of each cement type, a cementation jig or 3D-printed replica is highly recommended regardless of the cement type. [ABSTRACT FROM AUTHOR]

Surface contaminants on customized implant abutments could trigger an inflammatory response in the peri-implant tissues. The aim of this randomized controlled study was to assess the radiographic bone changes around implants restored with customized, platform-switched abutments, with and without autoclave treatment, 12 months after definitive restoration. Dental implants were placed 1 mm subcrestally in 64 systemically healthy patients (mean age: 63.3 ± 10.0 years; 31 patients had a history of periodontitis) to replace single or multiple missing teeth. According to a randomization list, abutments were subjected to steam and autoclave sterilization (43 implants, test group) or steam cleaning alone (44 implants, control group). Periapical standardized radiographs were taken at implant placement, prosthetic abutment connection, and 12 months after definitive cement-retained restoration. All implants were clinically stable without any sign of infection at the 12-month follow-up. An average marginal bone loss of 0.25 ± 0.19 mm was found in the test group compared to 0.35 ± 0.23 mm in the control group (no statistically significant difference), while the percentage of bleeding sites was significantly higher in the control group (8.7% ± 13.1% vs 19.1% ± 19.8%; P = .035). Autoclave treatment of customized abutments seems to reduce the inflammatory response around subcrestally placed implants. [ABSTRACT FROM AUTHOR]

Following implant placement, a soft tissue barrier will form at the healing abutment connection called peri-implant mucosa. The dimension of this anatomical structure seems to play a key role in maintaining long-term peri-implant and marginal bone level stability. In its early stages, soft tissue healing is a process involving many cellular and molecular events. Enamel matrix derivative (EMD) may improve and accelerate soft tissue wound healing and inflammatory resolution. In the present split-mouth randomized clinical trial, EMD was used to influence the early phase of soft tissue healing around dental implants placed with a single-stage approach into a completely healed ridge. A total of 60 implants were placed in 30 patients (2 implants per patient, one in the test group and one in the control group). In the test sites, EMD was administered around the healing abutment before soft tissues were sutured. Soft tissue healing index (HI) and secondary endpoints (clinical, radiographic, and patientreported outcomes) were measured. Better outcomes were recorded in patients receiving EMD for all parameters. The present results support the use of EMD to improve and accelerate soft tissue wound healing around implants. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the screw loosening and fracture resistance of different hybrid abutment crown restorations after thermomechanical aging. Materials and Methods: Restorations were produced from zirconia, lithium disilicate, and hybrid ceramics with a CAD/CAM system (n = 10). Restorations and titanium bases (Ti-bases) were cemented, and the abutment screws were torqued to 30 Ncm. They were retorqued after 10 minutes, and then the removal torque values (RTVs) were measured. After 250,000 and 500,000 cycles of thermomechanical aging were completed, the RTVs were measured again, and removal torque loss (RTL) ratios were calculated. The specimens were subjected to a fracture resistance test after 750,000 cycles of thermomechanical aging, and the load at failure was recorded as the fracture resistance (N). The results were statistically analyzed (a = .05). Results: Aging was effective on the RTVs and RTL ratios (P < .001). The highest RTV was observed before aging; however, the RTVs significantly decreased and RTL ratios significantly increased after aging (P < .05). The fracture resistance values significantly differed among the ceramic materials. All lithium disilicate and hybrid ceramic specimens showed restoration fracture and most of the zirconia specimens showed Ti-base-related failure. Conclusions: Hybrid abutment crowns made of zirconia, lithium disilicate, and hybrid ceramics can withstand the average occlusal forces in the molar region; however, the ceramic type may affect the failure type. Retightening of the abutment screws after 10 minutes following the first tightening and annually may be beneficial to prevent the adverse effects of screw loosening on the integrity of the implant-abutment connection. [ABSTRACT FROM AUTHOR]

Purpose: To examine the behavior and function of human gingival fibroblasts growing on healing abutments with or without laser-textured topography. Materials and Methods: Human primary gingival connective tissue fibroblasts were cultured on healing abutments with machined or laser-textured (Laser-Lok, BioHorizons) surfaces. Cellular and molecular responses were evaluated by a variety of tests, including cell density assay (WST-1), fluorescence microscopy, real-time quantitative reverse-transcription polymerase chain reaction (qRT-PCR), and detachment tests. Results: The machined surface showed monodirectional traces and scratches from milling, whereas the laser-textured surface showed a distinct morphology consisting of monodirectional mesoscale channels (15-µm pitch) and woven oblique microridges formed within the channels. There were no differences in initial fibroblast attachment, subsequent fibroblast proliferation, or collagen production between the machined and laser-textured surfaces. Fibroblasts growing on a laser-textured surface were found to spread in one direction along the mesochannels, while cells growing on machined surfaces tended to spread randomly. Fibroblasts on laser-textured surfaces were 1.8 times more resistant to detachment than those on machined surfaces. An adhesive glycoprotein (fibronectin) and transmembrane adhesion linker gene (integrin ß-1) were upregulated on laser-textured surfaces. Conclusions: The increased fibroblast retention, uniform growth, and increased transcription of cell adhesion proteins compellingly explain the enhanced tissue-level response to laser-created and hybrid-textured titanium surfaces. These results provide a cellular and molecular rationale for the tissue reaction to this unique surface; in addition, they support its extended use, from implants and healing abutments to diverse prosthetic components where enhanced soft tissue responses would be desirable. [ABSTRACT FROM AUTHOR]

Purpose: To assess the survival of double-crown-retained implant-and-tooth-supported removable partial dentures (DCR-ITSRPDs), evaluate abutment survival, and identify first aftercare measures. Materials and Methods: The influence of various factors on the survival of the DCR-ITSRPDs and the abutments were observed in this retrospective and clinical follow-up study using the Kaplan-Meier estimate. In addition, the first-required aftercare measure for each prosthesis was evaluated. Results: In total, 47 DCR-ITSRPDs were investigated (mean observation: 4.3 ± 3.8 years; max: 14.3 years), 3 of which (6.4%) had to be replaced. The survival probability for DCR-ITSRPDs was 100% at 5 years and 75% at 10 years. A total of 297 abutments (120 natural teeth and 177 dental implants) were observed, 22 of which (7.4%; 6 teeth and 16 implants) failed. The survival probability for teeth was 90.2% at the 5- and 10-year mark; for dental implants, it was 90.4% at 5 years and 76.3% at 10 years. Conclusions: DCR-ITSRPDs are a successful and durable treatment option for patients with substantially reduced residual dentitions. Both prostheses and abutments show good survival times after 5 and 10 years in function. The patient-associated factors tested showed no influence on the survival of DCR-ITSRPDs and abutments. Peri-implant infection was the decisive factor for abutment loss; therefore, regular dental prophylaxis and examinations are of major importance. [ABSTRACT FROM AUTHOR]

Purpose: To compare the effect of taper, length, angle, and number of vertical axial walls on the retentive strength of a cemented crown on a partially customized hybrid abutment in the esthetic zone. Materials and Methods: A total of 35 metal copings were used and divided into two groups. One group had 30 copings cemented to their corresponding 8-degree tapered abutment with lengths from 3 to 8 mm, increasing in 1-mm increments (5 copings per length). The other group had the remaining 5 copings and consisted of a standardized metal coping that matched a hexagonal abutment with 3-mm vertical axial walls and the sequential removal of 1, 2, and 3 contiguous vertical axial walls. Dislodgment tests were performed for all copings in both groups. Maximum retentive forces were measured in retentive strength (kgF), with a conversion factor of 9.807 N = 1 kgF. Results: At each tapered abutment length, the retentive strength increased proportionally and was significantly different, ranging from 31.67 ± 4.10 kgF to 67.68 ± 11.22 kgF (F [5,24] = 20.46, P < .001). An unmodified hexagonal abutment demonstrated the highest retentive strength (70.15 ± 12.97 kgF). The sequential removal of 1, 2, and 3 contiguous vertical axial walls of the hexagonal abutment resulted in retentive strength values of 59.89 ± 10.06 kgF, 57.01 ± 9.62 kgF, and 55.99 ± 9.35 kgF, respectively, with no significant difference (P > .05) in strength. Conclusions: A partially customized abutment with vertical axial walls on one side and a profile reduction on the opposite side can provide comparable retention to cemented copings at one-third the length and at one-sixth the surface area of an 8-mm abutment with an 8-degree taper. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate four decontamination strategies utilizing enzymatic agents available in most clinical settings to determine (1) the amount of biomaterial that can be removed in a group of previously used healing abutments (uHAs) and (2) the degree to which the decontaminated HAs are capable of inducing an inflammatory response in vitro compared to new HAs. Materials and Methods: In total, 50 HAs were collected following 2 to 4 weeks of intraoral use and distributed randomly into five test groups (groups A-E; n = 10 per group). Group A used enzymatic cleaner foam and an autoclave. Group B used an ultrasonic bath with enzymatic cleaner and an autoclave. Group C used a prophy jet, enzymatic cleaner foam, and an autoclave. Group D used a prophy jet, an ultrasonic bath with enzymatic cleaner, and an autoclave. Lastly, group E used a prophy jet and an autoclave. The control group consisted of 10 new and sterile HAs. Residual protein concentration was determined by a Micro BCA protein assay (Thermo Fisher Scientific), while HAs from each group were stained with Phloxine B and macroscopically examined for the presence of debris. To examine the inflammatory potential, human primary macrophages were exposed to HAs, and supernatant levels of nine cytokine and chemokine profiles were analyzed using a multiplex bead assay. Results: All test groups showed differences in the degree of visual decontamination compared to controls. Groups D and E displayed the most effective surface debris removal and reduced protein concentration, while group A was the least effective. However, compared to controls, all test groups showed high levels of inflammatory cytokine secretion via multiplex assay for up to 5 days. Conclusions: Our study found that decontamination of uHAs utilizing enzymatic cleaners failed to reestablish inert HA surfaces and prevent an inflammatory immune response in vitro. Clinicians should not reuse HAs even after attempts to decontaminate and sterilize HA surfaces. [ABSTRACT FROM AUTHOR]

Purpose: To assess the clinical concept of patient treatment with fixed tooth- and implant-supported restorations in a university-based undergraduate program after 13 to 15 years. Materials and Methods: In total, 30 patients (mean age 56 years) who had received multiple tooth- and implant-supported restorations were recalled after 13 to 15 years. The clinical assessment comprised biologic and technical parameters as well as patient satisfaction. Data were analyzed descriptively, and the 13- to 15-year survival rates for tooth- and implant-supported single crowns and fixed dental prostheses (FDPs) were calculated. Results: The survival rate of tooth-supported restorations amounted to 88.3% (single crowns) and 69.6% (FDPs); in implants, it reached 100% for all types of restorations. Overall, 92.4% of all restorations were free of technical complications. The most common technical complication was chipping of the veneering ceramic (tooth-supported restorations: 5.5%; implant-supported restorations: 13% to 15.9%) regardless of the material used. For tooth-supported restorations, increased probing depth = 5 mm was the most frequent biologic complication (22.8%), followed by endodontic complications of root canal-treated teeth (14%) and loss of vitality at abutment teeth (8.2%). Peri-implantitis was diagnosed in 10.2% of implants. Conclusions: The results of this study indicate that the clinical concept implemented in the undergraduate program and performed by undergraduate students works well. The clinical outcomes are similar to those reported in the literature. In general, the majority of biologic complications occur in reconstructed teeth, whereas implant-supported restorations are more prone to technical complications. [ABSTRACT FROM AUTHOR]

In our previous test model, the abutment teeth and the model base were printed with resin and bonded with a polyether material. Some abutment teeth were fractured during the mechanical load test. Therefore, the aim was to develop and evaluate a new model under mechanical loading until fracture with zirconia FPD frameworks. At a fracture load of up to 1,636 N, neither the artificial abutment teeth nor the base model fractured. Furthermore, the artificial abutment teeth did not detach from the base model. Therefore, the model should be suitable for mechanical testing of most ceramic-based framework materials for three-unit FPDs. [ABSTRACT FROM AUTHOR]

This document is a scientific study that examines the contamination levels on dental abutments and the effectiveness of a cleaning protocol. The study finds that custom-made abutments have surface pollutants, and laboratory procedures increase the amount of pollutants. However, the cleaning protocol tested is highly effective in cleaning both titanium and zirconia abutments. The study suggests that decontaminating abutments before placement may improve tissue integration. [Extracted from the article]

Purpose: The aims of the study were to evaluate the clinical performance and the complications of combined tooth-/implant-supported three-unit fixed partial dentures (FPDs) in the posterior mandible. Materials and Methods: A total of 78 partially edentulous patients in the posterior mandible were recruited for the study (n = 26/group). Group 1 served as the control group and received two dental implants to support a three-unit FPD. Groups 2 and 3 were the experimental groups in which one implant was placed in conjunction with support from an adjacent tooth to support a three-unit FPD. Standard implants (= 8 mm) were included in Group 2, while short implants (< 8 mm) were included in Group 3. Periapical radiographs were taken for evaluation of crestal bone loss (CBL). Modified plaque index (MPI), bleeding index (BI), and sulcus depth values of the abutment teeth were recorded at the time of FPD delivery, 6 months after FPD delivery, and annually thereafter. Recorded complications included abutment tooth intrusions, cementation failures of the restorations, porcelain chipping/delamination, framework fracture, abutment screw loosening, abutment and abutment screw fracture, and implant fracture. Results: Statistically significant differences were observed between Group 1 (0.06 ± 0.17) and Group 2 (0.18 ± 0.32) and between Group 1 and Group 3 (0.17 ± 0.30) in terms of MPI (P = .05). No difference was observed between Group 2 (0.11 ± 0.34) and Group 3 (0.14 ± 0.36) or between Group 1 (0.04 ± 0.22) and Group 2 in terms of BI. There were statistically significant differences in terms of CBL between Group 1 (0.259 ± 0.05 mm) and Group 3 (0.11 ± 0.03 mm) and between Group 2 (0.03 ± 0.03 mm) and Group 3 (P = .05). The mean abutment tooth sulcus depth was 1.11 ± 0.31 mm for Group 2 and 1.20 ± 0.46 mm for Group 3. Conclusions: Within the limitations of the current study, it was concluded that combined tooth/implant-supported prostheses (CTISPs) are a predictable treatment choice in the posterior mandible. When a CTISP is planned, it is more predictable to use a short implant than a standard-length implant. [ABSTRACT FROM AUTHOR]

Purpose: This prospective study evaluated the marginal bone level and periodontal parameters 6 years after placement of a convergent transmucosal neck implant. Materials and Methods: In total, 71 implants were placed in 60 patients. Of these, 52 implants were placed with a flapless technique and with the convergent neck exposed by 1 mm (early and delayed placement), while 19 implants were placed immediately after extraction (immediate placement). At least 3 months after insertion, customized abutments were applied and provisional resin crowns were cemented, while being careful to prevent any tissue compression. After 3 weeks, definitive metal-ceramic crowns were designed with the finish line at the soft tissue level and free from any compression. The implant survival rate at 6 years, marginal bone level changes (ΔMBL, mm), and Pink Esthetic Score (PES) were evaluated. Gingival phenotype was determined before the implant surgeries (thin/thick). A three-level hierarchical model was examined with a random intercept and random slope on follow-up time at the patient level and a random intercept at the implant level. Results: In all, 57 patients with 67 implants reached the 6-year point; 3 patients (5.0%) dropped out. The implant survival rate was 100%. ΔMBL from baseline to 24 months was 0.58 mm (95% CI: 0.48, 0.68), while ΔMBL from 24 to 72 months was 0.33 mm (95% CI: 0.19, 0.47). PES improved steadily from 6 to 48 months (+0.96; 95% CI: 0.71, 1.20), with overall stability at 72 months. No correlation between MBL and PES was observed. A significant association was found between thick gingival phenotype and less MBL variation. Greater implant diameter offered more MBL stability after 3 years but resulted in lower PES values. Conclusions: The use of convergent transmucosal neck implants placed with a flapless transmucosal approach with the crown margin positioned at the gingival level preserved marginal bone and guided gingival morphology for up to 72 months. The gingival phenotype was the parameter that most affected the soft and hard tissues. In the long term, implant placement timing was not related to MBL. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate and compare the difference in retention between implant-supported restorations with and without surface modification of the implant abutments. Materials and Methods: A total of 30 patients with singletooth implants were restored with cement-retained (Multilink N, Ivoclar) restorations using titanium base abutments (Variobase, Straumann) and randomly assigned surface modifications. Group 1 used nonmodified abutments, group 2 used sandblasted abutments, and group 3 used sandblasted abutments followed by an application of metal primer. All patients were recalled for a baseline examination 6 months after crown placement. The pull-out strength and intergroup distribution of mean pull-out strength were assessed. To assess differences between the three groups, intergroup statistical comparison of continuous variables was done using one-way ANOVA with Tukey correction for multiple group comparisons. Results: The results of the intergroup mean pull-out strength distribution revealed that the distribution of mean ± SD pull-out strength in group 1, group 2, and group 3 were 220.79 ± 94.23, 488.64 ± 84.12, and 705.46 ± 112.75 Ncm, respectively. Conclusions: Sandblasting followed by the application of metal primer produced the highest retention of porcelain-fused-to-metal (PFM) crowns to titanium base abutments, followed by sandblasting alone, with the least retention being observed with no surface treatment. [ABSTRACT FROM AUTHOR]

Purpose: To analyze the effectiveness of coating of abutments with antimicrobial agents and their influence on the physicochemical and biologic properties of the coated materials. Materials and Methods: This work was registered in Open Science Framework (osf.io/6tkcp) and followed the PRISMA protocols. A search of two independent reviewers of articles published up to October 29, 2021, was performed in the Embase, PubMed, Science Direct, and Scopus databases. Results: The databases found a total of 1,474 references. After excluding the duplicates, 1,050 remained. After reading the titles and abstracts and applying the inclusion criteria, 13 articles remained and were read in full. A total of 8 articles were included in this systematic review. Different antimicrobial agents have been used to coat abutments, including graphene oxide, polydopamine, titanium and zirconium nitride, lactoferrin, tetracycline, silver, and doxycycline with varied release times. Titanium-coated silver showed a better antimicrobial agent release time of up to 28 days. Chemical analysis confirmed the presence of antimicrobials on the surface after coating. Different pathogenic microorganisms, such as Streptococcus sanguinis, Streptococcus oralis, and Staphylococcus aureus, were inhibited when in contact with the coated surface. Conclusions: This review showed that there is still no consensus on which is the better antimicrobial agent and which coated materials have the better performance. However, the association of surface coating of abutments with antimicrobials is feasible and can benefit many patients, which can support their clinical use to favor the healing process and prevent infections that can lead to treatment failure with dental implants. [ABSTRACT FROM AUTHOR]

The article discusses the results of a study which evaluated the effectiveness and accuracy of a proposed duplication technique in terms of one- and three-dimensional discrepancies between an original abutment and polyurethane duplicates obtained through a conventional workflow in single-implant rehabilitation. Topics covered include master cast with the Giroform System, abutment duplication and the influence of duplication on crown marginal and internal adaptation.

The article "Digital Technology: A Tool for the Treatment of Implant Reintervention" in Quintessence of Dental Technology discusses a case study of nonesthetic rehabilitation of a maxillary right central incisor with an implant. The use of digital planning tools facilitated safe and efficient interdisciplinary treatment involving cosmetic surgery and prosthetic rehabilitation. The article emphasizes the importance of proper planning and the use of digital tools to ensure predictable outcomes and simplify the treatment process. [Extracted from the article]

Purpose: To determine the characteristics of dental implant transmucosal surfaces that influence soft tissue attachment and marginal bone loss (MBL). Materials and Methods: The PubMed, Embase, and Cochrane Library electronic databases were searched based on predefined PICO eligibility criteria. Data from animal studies that compared junctional epithelium and connective tissue attachment and MBL from 4 days to 72 weeks were analyzed. The risk of bias was performed with the Systematic Review Centre for Laboratory Animal Experimentation tool. A rank analysis evaluation of data was performed, and the most frequently appearing materials/surfaces for each tissue compartment were identified. Results: The search identified 3,549 studies, 28 of which were eligible for analysis, with an average risk of bias of 28% ± 10%. Machined, polished, etched, sandblasted, or coated titanium and zirconia materials/surfaces were most frequently examined. Several studies investigated lithium disilicate, polyether ether ketone (PEEK) or polyether ketone ketone (PEKK), aluminum oxide, and gold. Based on ranking and frequency of use at different time points, titanium grade IV (Ti-4) microthreads with a polished neck area most frequently supported natural tooth-like junctional epithelial attachment (= 1.5 mm), while machined Ti-4 and machined titanium grade V (Ti-5) most frequently supported connective tissue attachment (= 1.25 mm) and led to the least MBL (= 0.75 mm). Conclusions: Analyzed data suggest that Ti-4 microthreads with a polished neck area and machined Ti-4 and Ti-5 were the materials/surfaces of choice for the transmucosal part of implants. However, the extensive heterogeneity in reported studies precludes solid identification of the best materials/surfaces. [ABSTRACT FROM AUTHOR]

Purpose: This in vitro study investigated the effect of implant geometry and diameter on the rotational load fatigue performance of an implant system with an internal conical connection with microthreads. Materials and Methods: Regular (4.2 mm) and wide-diameter (4.8 mm) Astra Tech EV implants with straight (S) and conical (C) geometries were tested with their corresponding titanium abutments, comprising four test groups: 4.2-mm S (Group 1), 4.2-mm C (Group 2), 4.8-mm S (Group 3), and 4.8-mm C (Group 4). Five samples were included in each group. Customized brass implant holders and abutment holders were machined. A rotational load fatigue machine was used to apply a sinusoidally varying load to the implant-abutment interface at an angle of 45 degrees to produce an effective bending moment of 35 Ncm at a frequency of 14 Hz (air temperature: 20°C). The number of cycles to failure was recorded, with the upper limit set at 5 × 106 cycles. Results were analyzed using ANOVA. Failed samples were examined with a scanning electron microscope to evaluate the mode of failure. Results: Of the 20 total samples, 2 failed, with Groups 1 and 2 each reporting one failure. Abutment and abutment screw fracture were observed in the failed sample in Group 1, while implant and abutment screw fracture occurred in the failed sample in Group 2. All wide-diameter implants ran beyond the cut-off without failure, but abutment screw loosening was noted in one sample in Group 3. No significant difference was found between implant groups of different geometries and diameters. Damage to the abutments and the implant internal surface were noted in all failed samples. Conclusions: While no significant differences were found between the test groups, failures were observed only in the regular-diameter group. The abutment and abutment screw fractured deep within the implant, and the implant fractured below the simulated bone level. These modes of failure may pose a significant clinical challenge during retrieval of these components. [ABSTRACT FROM AUTHOR]

Objective: The purpose of this study was to evaluate the effect of different preparation depths (0, 2 and 4 mm) of different restoration designs (classic endocrown design versus overlay design) on marginal adaptation of restorations fabricated of two different restorative materials (lithium disilicate and PEEK). Materials and methods: Sixty mandibular natural molars were collected as abutments for the restorations of this study, and grouped in three main groups of different cavity depths (0, 2 and 4). Each group was divided into two subgroups according to material of fabrication to (L) for lithium disilicate (IPS emax CAD, Ivoclar vivadent, Switzarland) and (P) for PEEK (Bio-hpp, Bredent, Germany). CAD/CAM milling technology was used for fabrication of restorations. After cementation of restorations over abutments, hydrothermal aging was performed, and then marginal adaptation was evaluated via micro CT technology. Results: Regarding cavity depths, there was a significant difference between different groups (p < 0.001). The highest value was found in samples with 4 mm extension (84.35 ± 18.16), followed by samples with 2 mm extension (66.52 ± 21.86), while the lowest value was found in samples without pulpal extension (59.41 ± 22.16). Post hoc pairwise comparisons showed samples with 4 mm extension to have a significantly higher value than samples without extension (p < 0.001). Regarding materials of fabrication, PEEK (85.32 ± 12.37) had a significantly higher value than Emax (54.86 ± 20.86) (p < 0.001). Conclusions: Increasing intrapulpal cavity depths increases vertical marginal gap of lithium disilicate or PEEK restorations. Endocrowns fabricated of lithium disilicate show less marginal discrepancies than that of endocrowns fabricated of PEEK. [ABSTRACT FROM AUTHOR]

Background: The maintenance of the integrity of the anterior dentition plays a vital role in maintaining the beauty of the face. The repair schemes of anterior teeth loss mainly include implant denture, traditional fixed bridge, bonding bridge and removable partial denture. Among them, the bonding bridge is a minimally invasive fixed denture repair method that relies on bonding technology for retention, which has the advantages of simple operation, a small amount of grinding of the required abutment teeth, comfort, beauty, and no self-removal. Therefore, we reported a case of digital guide plate-assisted resin-based ceramic bonding bridge repair of anterior teeth loss. Case report: A 28-year-old woman was admitted to our hospital because left upper anterior teeth missing for more than 3 months. Minimally invasive tooth preparation assisted by digital guide plate+resin-based ceramic single-ended bonding bridge repair were performed. After treatment, the ideal clinical effect was achieved. Conclusion: Slightly tooth preparation with the assistance of a digital guide plate is used to guide the precise bonding of the prosthesis in repairing anterior teeth loss. [ABSTRACT FROM AUTHOR]

Background: Examining stress distributions in abutment teeth with periapical lesions is essential for understanding their biomechanical impact on dental structures and tissues. This study uses finite element analysis (FEA) to evaluate these stress patterns under occlusal forces, aiming to enhance treatment strategies and prosthetic designs. Methods: Three FEA models were created: a healthy mandibular premolar (Model 1), a premolar with a single crown and a lesion repaired using a fiber-post (Model 2), and 3) a premolar with a lesion repaired using fiber-post to support a four-member bridge (Model 3). A 300 N occlusal static stress was given to each model at a 45° angle to the long axis of the tooth, namely at the lingual inclination of the buccal-cusp. Deformation behaviour and maximum equivalent stress distributions were simulated on the all components, including the bony structure for each model. Results: The study showed a reduction in equivalent stress levels in trabecular and cortical bone, crown, cementum, and PDL under occlusal force, from Model 1 to Model 3. The Von Mises yield criteria values of the tooth models differed depending on the prosthetic restorations, with the highest value seen in Model 2 (133.87 MPa). Similar locations in all models showed concentrated equivalent stresses for all components. The periapical lesion area exhibited relatively low stress values for Models 2 and 3, at 0.061 MPa and 0.039 MPa, respectively. The largest level of stress was seen in the cervicobuccal areas of the tooth in all models. Conclusion: Prosthetic restorations on teeth with periapical lesions resulted in varying stress and biomechanical responses in the tooth and surrounding bone tissue. These teeth can serve as abutments in a four-unit bridge when subjected to optimal occlusal stresses, based on the findings. [ABSTRACT FROM AUTHOR]

Background: The mechanical properties of framework materials significantly influence stress distribution and the long-term success of implant-supported prostheses. Although titanium, cobalt-chromium, zirconia, and polyether ether ketone (PEEK) are widely used, their biomechanical performance under dynamic loading conditions remains insufficiently investigated. This study aimed to evaluate the biomechanical behavior of four framework materials with different Young's modulus using dynamic finite element stress analysis. Methods: A 3D edentulous maxillary model was extracted from a computer tomography (CT) database. Bone level implants with conical connection designs were placed in the anterior (canine) and posterior (first molar) areas. Anterior implants were parallel, yet posterior implants were inclined distally by 30 degrees. According to the framework material, four groups were formed: cobalt-chromium (Co-Cr), zirconia (Zr), titanium (Ti), and polyether ether ketone (PEEK). For each framework material, twelve separate models of analysis were created by applying force in three different orientations. Dynamic forces were employed to replicate the chewing process. Principal and von Mises stresses were measured and evaluated. Results: The PEEK framework exhibited the highest maximum von Mises stress values (372.55 MPa) on the abutment and the highest maximum principle stress values (59.27 MPa) in the cortical bone. The Co-Cr framework had the lowest minimum principle stress (3.98 MPa) in the trabecular bone. The displacements of the Co-Cr, Zr, Ti, and PEEK frameworks were 0.15 mm, 0.15 mm, 0.17 mm, and 0.35 mm, respectively. Conclusion: Frameworks having a greater Young's modulus are less susceptible to deformation. [ABSTRACT FROM AUTHOR]

Dental implants are crucial in contemporary oral rehabilitation, necessitating optimal integration with the surrounding soft tissues for durable success. The attachment between the implant surface and peri-implant mucosa should establish a secure seal to prevent bacterial infiltration and subsequent tissue inflammation. This concise review examines the histological and biological perspectives of peri-implant soft tissue reactions to zirconium and titanium abutments, shedding light on their respective advantages and limitations. While titanium has been the gold standard, zirconia has gained attention due to its biocompatibility and aesthetic appeal. Histological studies show comparable soft tissue attachment and inflammatory responses between the two materials. Further research is needed to explore surface treatments and optimize outcomes in dental implant rehabilitation. [ABSTRACT FROM AUTHOR]

Infections continue to pose significant challenges in dentistry, necessitating the development of innovative solutions that can effectively address these issues. This study focuses on creating coatings made from polymethyl methacrylate (PMMA) enriched with zinc oxide–silver composite nanoparticles, layered to Ti6Al4V–titanium alloy substrates. The application of these materials aims to create a solution for the abutments utilized in complete dental implant systems, representing the area most susceptible to bacterial infections. The nanoparticles were synthesized using a hydrothermal method, optimized through specific temperature and pressure parameters to achieve effective morphologies and sizes that enhance antibacterial efficacy. The layers were applied to the titanium substrate using the spin coating technique, chosen for its advantages and compatibility with the materials involved. Comprehensive analyses were conducted on the antimicrobial powders, including X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. Furthermore, the PMMA-based coatings incorporating antimicrobial nanoparticles were evaluated to ensure uniformity and homogeneity across the titanium alloy surface by IR mapping and SBF immersion–SEM analysis. The antimicrobial activity of the samples was demonstrated with impressive results against Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans, as assessed through biofilm modulation studies. The biocompatibility of the samples was validated through in vitro cell-based assays, which demonstrated excellent compatibility between PMMA-based coatings and human preosteoblasts, confirming their potential suitability for future use in dental implants. [ABSTRACT FROM AUTHOR]

Background: Anatomically formed healing abutments were suggested in literature to address many of the issues associated with immediate posterior implant insertion such as large extraction sockets that are extremely hard to seal without reflecting the mucoperiosteal flap, extraction sockets anatomy that are not suitable for regular healing abutment placement, and potentially high occlusal stresses when planning a temporary implant supported prothesis to improve the conditioning of supra implant tissue architecture and the emergence profile of the implant supported restorations. Purpose: To clinically evaluate the peri-implant soft tissue profile of single posterior implant retained restorations and to assess patient related outcomes of the implant restorations that were conditioned immediately by CAD-CAM socket sealing abutments (SSA) versus those conditioned by Titanium (Ti) standard healing abutments (SHA). Methods: Twenty participants received twenty-two single maxillary immediate implants after flapless minimally invasive tooth extraction and 3D guided implant placement in the posterior area (premolar and molar) and allocated randomly into two groups (n = 11), the intervention group: patients received PEEK SSA and the control group: the patients received Ti SHA. Modified Pink Esthetic Score (PES) was evaluated at 3 observation periods: Baseline T0 (immediate after implant supported crown insertion), 6 months T1 and 1 year of clinical performance T2. Patient satisfaction was assessed one week and one year after crown insertion using visual analogue scale (VAS). Results: At base line, after six as well as 12 months, SSA group showed statistically significant higher total modified PES scores than SHA group (P-value < 0.001). At the 2 clinical observation periods (baseline and after one year), SSA group showed statistically significantly higher overall satisfaction score than SHA group (P-value < 0.001). Conclusion: After one year of clinical observation period, CAD-CAM PEEK socket sealing abutments together with flapless minimally invasive tooth extraction and 3D guided implant placement provided superior outcomes compared to Ti SHA in terms of peri-implant soft tissue profile. Trial registration: This study was registered on clinicaltrials.gov with ID no. NCT05276765 on 03/03/2022. [ABSTRACT FROM AUTHOR]

ABSTRACT Background/Aim Materials and Methods Results Conclusion Studies on large cross‐arch bridges in patients with severe periodontitis show that such bridges can stabilize the periodontal condition. However, it is not known if these bridges will reduce long‐term tooth loss and what factors are important for their long‐term survival. The aim of the study was to study all patients with Stages III/IV periodontitis who received cross‐arch bridges for up 35 years in a private practice.All patients referred for periodontal treatment from 1986 who received cross‐arch bridges with observation period of minimum 7 years were assessed. All dropouts were accounted for.Ninety‐eight patients (1.7% of the patient population) with 111 bridges were observed (57 females and 37 males). Age at bridge construction was 55.4 years (SD = 7.1, range 39–79). Failure rate was 14.4% at 16.1 years (SD = 4.0 range 10–22). Reasons for failure were poor oral hygiene (p = 0.0093) and complications such as caries, endontics, porcelain fractures and gingival retractions during maintenance therapy (p = 0.0059). Fewer abutment teeth were lost from the bridges than teeth from the same and opposing arches (8.8% vs. 34.4% and 25.4%) (p < 0.0001).Cross‐arch bridges constructed for patients with Stages III and IV periodontitis were successful in terms of longevity, low failure rates, tooth preservation and patient satisfaction. [ABSTRACT FROM AUTHOR]

Polyetheretherketone (PEEK) has emerged as a revolutionary material in modern dentistry because of its unique combination of mechanical strength, biocompatibility, and versatility. This literature review examines the current applications and future potential of PEEK in various dental disciplines. PEEK's favorable properties, including its low specific weight, high strength-to-weight ratio, and ability to be easily machined, have led to its adoption in prosthetics, implantology, and dental esthetic restorations. This material has shown promise for fabricating crowns, bridges, removable partial denture frameworks, and implant components. PEEK's radiolucency and bone-like elastic modulus make it particularly suitable for dental implants and abutments. Additionally, its resistance to degradation and compatibility with various surface treatments enhances its long-term performance in the oral environment. While challenges such as bonding to other dental materials and aesthetic limitations exist, ongoing research is addressing these issues through surface modifications and composite formulations. As the dental field continues to evolve, PEEK's adaptability and biocompatibility position it a key player in the development of next-generation dental materials and techniques, potentially transforming patient care and treatment outcomes in dentistry. [ABSTRACT FROM AUTHOR]

Objectives: This study aimed to assess the effect of cyclic loading on the amount of fixture‐abutment microgap in short implants compared to standard implants. Materials and Methods: This in vitro experimental study was conducted on two groups of short and standard implants (n = 10). The microgap at the fixture‐abutment interface was measured under a light microscope at ×75 magnification. The implants were mounted in an acrylic resin to simulate the jawbone. They were then subjected to cyclic loading by applying 75 N load with 1 Hz frequency along the longitudinal axis of each implant (perpendicular to the abutment surface). After 500,000 cycles, corresponding to 20 months of mastication in the oral environment, the implants were removed from the acrylic resin, and the microgap at the fixture‐abutment interface was measured again under a stereomicroscope by a blinded examiner. Data were then analyzed by t‐test using SPSS version 22 (α = 0.05). Results: The mean microgap was 13.59 ± 3.80 µm in the standard and 20.41 ± 11.30 µm in the short implants before cyclic loading (p = 0.087). These values changed to 15.22 ± 5.44 and 24.53 ± 21.85 µm, respectively, after cyclic loading. No significant difference was noted in the amount of microgap between the standard and short implants after cyclic loading (p = 0.222). Conclusion: Cyclic loading increased the amount of fixture‐abutment microgap in both the standard and short implants. However, the difference in this respect was not significant between the two implant lengths. Thus, short implants could be reliably used in patients with limitations for surgery to restore function and esthetics. [ABSTRACT FROM AUTHOR]

ABSTRACT Objective Clinical Considerations Conclusions This clinical case describes a multidisciplinary retreatment of a patient with anterior fixed dental prostheses (FDPs) using minimally invasive restorations and a biologically oriented preparation technique (BOPT).A 56‐year‐old female patient, treated 30 years ago with a metal‐ceramic FDP due to dental agenesis, presented a misfit prosthesis at the gingival margin, black spaces, and food retention at the pontics. Notably, tooth number 2.6 was absent, and she exhibited a left crossbite. Her chief complaint was the compromised esthetics of her restorations. Given her coagulation disorder, von Willebrand disease, she declined mucogingival surgery. A diagnostic wax‐up and mock‐up was performed to establish treatment goals. The initial phase involved periodontal, orthodontic, and implant treatment. The orthodontic treatment with aligners to correct the crossbite. Subsequently, bleaching and a second mock‐up were conducted to guide prosthetic treatment. In the prosthodontic treatment, the abutment teeth were prepared using a vertical BOPT to remodel the gingival tissues, achieving the esthetic goal of repositioning the gingival margin without surgery. The provisional phase was critical for soft tissue remodeling and ensured clinical success. After stabilization of the soft tissues, a monolithic zirconia FDP was delivered, with a follow‐up of 2 years.A multidisciplinary treatment plan, utilizing a digital workflow, resulted in stable clinical and esthetic outcomes at the two‐year follow‐up, effectively retreating an anterior bridge using BOPT in a patient with a coagulation disorder that contraindicated complex surgical interventions. [ABSTRACT FROM AUTHOR]

ABSTRACT Objectives Materials and Methods Results Conclusion Variations in transmucosal abutment contour design may affect the outcomes of implant therapy. This randomized controlled trial was primarily aimed at testing the effect that CAD/CAM zirconia abutments with either a concave or linear divergent transmucosal morphology have on peri‐implant mucosal dynamics and indicators of peri‐implant health at 1 year after final implant‐supported prosthesis insertion in the anterior maxilla.Following computer‐guided implant placement and osseointegration, eligible subjects were randomized into either the experimental (concave morphology) or the control (linear divergent morphology) group. A comprehensive set of outcomes of interest related to peri‐implant soft tissue dynamics, phenotypical features, and indicators of peri‐implant health were assessed at different time points over a 1‐year period after insertion of the final restoration.Out of 60 initially recruited subjects, a total of 54 completed the study (n = 29 in the experimental group concave/n = 25 in the control group). Overall implant survival and restoration rates between master impression and 12 months were 100% and 98.2%, respectively. Although a trend for coronal migration of the buccal mucosa zenith, gain in mucosal thickness, and increased probing depth and bleeding on probing was observed in both groups, these changes were clinically negligible, and no substantial differences were observed between study groups regardless of variations in transmucosal abutment morphology.The use of either linear divergent or concave custom CAD/CAM zirconia abutments in a screw‐retained, delayed loading approach yielded no significant differences. [ABSTRACT FROM AUTHOR]

ABSTRACT Aim Materials and Methods Results Conclusions Biomechanical performance is a critical factor in the long‐term success of dental implants, with abutment screw loosening being a common clinical issue. This study aimed to examine the impact of abutment screw design and external load loading angles on abutment screw loosening.Abutments and abutment screws with 30°, 60°, 90°, and 180° fitting tapers were fabricated and tested for preload and initial loosening torque. Subsequently, dynamic loosening tests were conducted at loading angles of 15°, 30°, and 45°. Finite element analysis (FEA) was used to calculate the stress and strain distribution of the abutment screws.The findings indicated that large‐taper abutment screws exhibit a higher preload, whereas small‐taper abutment screws demonstrate greater loosening torque values. Additionally, as the loading angle increases, the loosening torque value decreases, and the stress and strain values of the abutment screw increase.Abutment screws with smaller taper heads exhibited superior resistance to loosening. Moreover, the anti‐loosening performance of the abutment screws decreased with higher external load loading angles. [ABSTRACT FROM AUTHOR]

Objectives: To compare marginal bone levels, biological, and technical outcomes of screw‐retained versus cemented all‐ceramic implant‐supported zirconia‐based single crowns after an observation period of 7.5 years. Methods: Forty‐four single implants in the esthetic zone in 44 patients (22 females, 22 males) were randomly assigned to two types of restorations: SR (screw‐retained); veneered one‐piece zirconia abutment and CR (cement‐retained); veneered lithium disilicate crown intraorally cemented on a one‐piece zirconia abutment. Patients were recalled annually up to 7.5 years and survival rates, biological, and technical parameters assessed. Results: A total of 31 patients attended the 7.5‐year follow‐up visit (17 SR group, 14 CR group). The survival rate on the restorative level was 77.5% (74.0% CR, 81.0% SR, p =.6399). Median marginal bone loss (MBL) values yielded −0.073 mm (−0.305; 0.238) in the CR and −0.215 mm (−0.500; 0.555) in the SR group (intergroup p =.6194). Mean bleeding on probing (BoP) values were significantly in favor of group SR with 20 ± 17% compared to 40 ± 22% in group CR (p =.011). The overall biological complication rate amounted to 27.5% (42.1% CR, 14.3% SR, p =.0775), whereas the technical complication rate was 32.5% (42.1% CR, 23.8% SR, p =.314). In total, CR restorations showed significantly more complications (84.2% for CR, 38.1% for SR, p =.0041). Conclusion: One‐piece zirconia‐based single crowns on two‐piece dental implants exhibited a high rate of technical and biological complications at 7.5 years of follow‐up. Cemented restorations revealed significant higher rates of bleeding on probing and total complications compared to screw‐retained restorations. [ABSTRACT FROM AUTHOR]

Introduction: Interim prosthesis play an important role in maintaining integrity of abutment tooth till final prosthesis is fabricated. Thus, using different fabrication techniques which can affect the mechanical properties of material can be useful to determine longevity of prosthesis. Aim: To evaluate the marginal gap and Flexural Strength (FS) of Computer-aided Designing/Computer-aided Milling (CAD/CAM) milled, 3D printed and conventional chairside interim 3-unit Fixed Dental Prosthesis (FDP). Materials and Methods: The present in-vitro study conducted in the Department of Prosthodontics, Bharati Vidyapeeth Dental College and Hospital, Sangli, Maharashtra, India, for duration of one year and six months between May 2022 to November 2023, 45 dies were fabricated by 3D printing technique. A total of 45 3-unit fixed dental prosthesis were fabricated over these dies by various techniques i.e., CAD/CAM Milled, 3D Printed and Conventional i.e., 15 sample per group I and J. All samples were cemented on dies under 20 N force and were evaluated for marginal gap with stereomicroscope under 40X magnification and assessed in millimetre (mm). Mean of marginal gap at premolar and molar for each sample was evaluated. Thermocycling was carried out for 5,000 cycles in distilled water (5°C and 55°C) in a digitally controlled water-bath chamber. Universal testing machine was used to evaluate FS using "three-point bend test". One-way ANOVA and Post-hoc Tukey's Honest Significant Difference (HSD) test were used for statistical analysis. Results: On evaluation of marginal gap, a significant difference was noted between the three groups with p-value=0.0006 with 3D printed group showing the most marginal gap. On evaluation of FS, a significant difference was noted between the three groups with p-value=0.0001. On pair-wise comparison, highly statistically significant difference was seen between all groups where CAD/CAM Milled showed greater FS followed by conventional and 3D printed. Conclusion: The CAD/CAM Milled showed better marginal adaptation and greater FS followed by conventional and 3D printed group. [ABSTRACT FROM AUTHOR]

Aim: This nationwide population‐based cohort study aimed to assess the incidence of implant complication treatments, including implant removal procedures and peri‐implantitis treatments, in relation to implant surfaces and abutment types. Methods: Data from the National Health Insurance Service, covering approximately 50 million individuals, were used. Implants and abutments were categorized by codes, including surfaces such as resorbable blasting media, sandblasted large grit and acid‐etched (SA) and hydroxyapatite coating, along with abutment structures (one‐piece straight, two‐piece straight, angled). The incidence of implant complication treatments was analysed using Kaplan–Meier curves and Cox proportional hazards regression (α = 0.05). Results: The study included 2,354,706 implants. The SA group had the lowest hazard ratio for implant removal procedures (p < 0.0001). No significant differences were found in the risk of peri‐implantitis treatments between implant surfaces (p = 0.0587). The risk of implant complication treatments did not differ significantly by the abutment type (p = 0.9542). The incidence rate of implant complication treatments was < 3.9 per 1000 implant‐years across all groups. Conclusions: The SA group showed a slightly lower risk of late implant loss, whereas no significant association was found for the abutment type groups. All implant and abutment type groups showed an incidence rate of < 3.9 per 1000 implant‐years for complication treatments. [ABSTRACT FROM AUTHOR]

Aim: To assess the influence of the emergence angle on marginal bone loss (MBL) and supracrestal soft tissue around dental implants. Materials and Methods: In six mongrel dogs, the mandibular premolars and molars were extracted. After 3 months of healing, four dental implants were placed in each hemimandible. The implants were randomly allocated to receive one of four customized healing abutments, each with a different value of the restorative emergence angle: 20°, 40°, 60° or 80°. Intra‐oral radiographs were taken after placing the healing abutments and at 6, 9, 16 and 24 weeks of follow‐up. Then, micro‐CT and undecalcified histology and synchrotron were performed. MBL over time was analysed with generalized estimating equations (GEEs) and adjusted for baseline soft‐tissue thickness. Results: From implant placement to 24 weeks, GEE modelling showed that the MBL at mesial and distal sites consistently increased over time, indicating MBL in all groups (p < 0.001). The model indicated that MBL varied significantly across the different restorative angles (angle effect, p < 0.001), with 80° showing the greatest bone loss. Micro‐CT, histology and synchrotron confirmed the corresponding trends and showed that wide restorative angles (60° and 80°) impaired the integrity of the junctional epithelium of the supracrestal tissue. Conclusions: A wide restorative angle increases MBL and impairs the integrity of the junctional epithelium of the implant supracrestal complex. [ABSTRACT FROM AUTHOR]

Background: 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. Materials and Methods: 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. Results: 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. Conclusion: 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. [ABSTRACT FROM AUTHOR]