Implant-supported Single Crowns Research Articles

A method for decontaminating a dental implant and components after abutment screw loosening: A clinical report

Abutment screw loosening is the most common complication in single implant-supported crowns, typically remedied by simply reattaching the restoration, preferably using a new abutment screw. The internal aspect of the implant along with any other components should be decontaminated before reconnection. This clinical report provides information on the appropriate management of the decontamination process, as well as evidence of the foreign material found within the implant body.

Failure resistance of single-implant crowns assembled from polyetheretherketone and lithium disilicate abutments and different crown materials after artificial aging.

The objective of the present study was to investigate the effect of using different materials for the fabrication of implant abutments and crowns on the mechanical behavior of implant-supported single crowns after artificial aging. The materials were tested in different combinations to reveal whether using stiff or resilient materials as an abutment or a crown material might influence the fracture strength of the whole structure. A total of 40 implants (blueSKY) were restored with identical custom-made CAD/CAM abutments milled out of lithium disilicate or ceramic-reinforced polyetheretherketone (PEEK) and divided into five test groups (n = 8). Forty crowns made of three different materials (zirconia, lithium disilicate, and ceramic-reinforced PEEK) were used to restore the abutments. Specimens were subjected to mechanical loading up to 1,200,000 cycles in a chewing simulator (Kausimulator) with additional thermal cycling. The surviving specimens were subjected to quasi-static loading using a universal testing machine (Z010). The PEEK abutments with zirconia crowns showed the highest median failure load (3890.5 N) while the PEEK abutments with lithium disilicate crowns exhibited the lowest (1920 N). Fracture and deformation occurred in both the crowns and abutments. The failure load of the restorations was influenced by the material of the abutment and crown. Restoring PEEK abutments with zirconia crowns showed a high failure load and no screw loosening.

Objective Esthetic Evaluation of Implant-Supported Single Crowns

Objective Esthetic Evaluation of Implant-Supported Single Crowns

Comparison of fatigue lifetime of new generation CAD/CAM crown materials on zirconia and titanium abutments in implant-supported crowns: a 3D finite element analysis.

Due to the dynamic character of the stomatognathic system, fatigue life experiments simulating the cyclic loading experienced by implant-supported restorations are critical consideration. The aim of this study was to examine the effect of different crown and abutment materials on fatigue failure of single implant-supported crowns. Models were created for 10 different designs of implant-supported single crowns including two zirconia-reinforced lithium silicates (crystallized and precrystallized), monolithic lithium disilicate, polymer-infiltrated ceramic networks, and polyetheretherketone supported by zirconia and titanium abutments. A cyclic load of 179 N with a frequency of 1 Hz was applied on palatal cusp of a maxillary first premolar at a 30° angle in a buccolingual direction. In the models with titanium abutments, the polymer-infiltrated ceramic network model had a lower number of cycles to fatigue failure values in the implant (5.07), abutment (2.30), and screw (1.07) compared to others. In the models with zirconia abutments, the crystallized zirconia-reinforced lithium silicate model had a higher number of cycles to fatigue failure values in the abutment (8.52) compared to others. Depending on the fatigue criteria, polyetheretherketone implant crown could fail in less than five year while the other implant crowns exhibits an infinite life on all models. The type of abutment material had an effect on the number of cycles to fatigue failure values for implants, abutments, and screws, but had no effect on crown materials. The zirconia abutment proved longer fatigue lifetime, and should thus be considered for implant-supported single crowns.

Long-term retention and survival of cemented implant-supported zirconia and metal-ceramic single crowns: A retrospective study.

To evaluate the effect of different cement types on the incidence of failure and loss of retention of zirconia and metal-ceramic single crowns (SCs) cemented on implant abutments. We placed 567 implant-supported SCs in 358 patients and retrospectively evaluated long-term retention for up to 12.8 years. The frameworks were made from metal alloy (n = 307) or zirconia (n = 260). SCs were cemented with permanent (glass-ionomer cement; n = 376) or semipermanent cement (zinc oxide non-eugenol cement; n = 191) on standardized (n = 446) or customized (n = 121) abutments. Kaplan-Meier curves were used to calculate the incidence of decementation. Differences between survival curves were assessed with log-rank tests. Cox-regression analysis was performed to evaluate multiple risk factors. Of the 567 SCs, 22 failed because of technical complications and four because of implant loss. Loss of retention was observed in 50 SCs. Analysis revealed a 7% probability of loss of retention for zirconia and 16% for metal-ceramic SCs after 10 years (p = .011). After 5 years, loss of retention was higher for standardized abutments than for customized abutments (p = .014). The probability of loss of retention was higher with semipermanent than with permanent cement (p = .001). Cox-regression analysis revealed semipermanent cement as the only significant risk factor for SC failure (p = .026). In contrast to semipermanent cement, permanent cement provides acceptable long-term retention of cemented implant-supported SCs. These possible positive effects of customized abutments have to be controlled with larger sample sizes.

Impact of Interproximal Features on Marginal Bone Level Changes of Autograft, Allograft, and Xenograft after Functional Loading: A Retrospective Study

Abstract Aim: This study aims to investigate the marginal bone level changes (MBLCs) concerning interproximal features of posterior implant-supported single crowns using different bone grafts. Materials and Methods: This retrospective study included 27 patients requiring 46 dental implants using autograft, allograft, or xenograft between January 2007 and December 2016. MBLCs were assessed using digital periapical radiographs at 3 months (T1), 12–15 months (T2), and 21–24 months (T3) after prosthesis delivery. The influence of interproximal features, such as embrasure surface area, emergence angle, and horizontal distance to adjacent teeth/implants, was assessed. Secondarily, age, gender, diabetes and smoking, arch distribution, implant locations, implant characteristics, average gonial angle, antagonist type, clinical crown-to-fixture ratio, retention method, and nearby tooth/implant were considered. Wilcoxon signed-rank test, Mann–Whitney U tests, and Kruskal–Wallis tests were employed with statistical significance set at a P value of <0.05. Results: The results revealed that mean MBLCs at T3–T1 were similar (autograft 0.5 ± 0.47 mm, allograft 0.51 ± 0.35 mm, and xenograft 0.57 ± 0.42 mm). There were significant increases in MBLCs associated with EA ≤ 30° in autograft (P = 0.04), and HD ≤ 3 mm in allograft (P = 0.03). Mesial/distal MBLCs showed no significant differences, except in cases with HD ≤ 3 mm in the distal area of autograft (P = 0.03). Regarding secondary factors, significant differences in MBLCs emerged between autograft and xenograft in the molar area (P = 0.03), and between premolar and molar areas within the xenograft group (P = 0.01). Conclusion: This study concludes that interproximal features, EA ≤ 30° and HD ≤ 3 mm, markedly influenced MBLCs for specific types of bone grafts. Furthermore, MBLCs exhibited a direct relationship with the posterior placement of dental implants.

Fifteen-year recall period on zirconia-based single crowns and fixed dental prostheses. A prospective observational study

AimThe aim of this study was to evaluate the long-term clinical outcomes of zirconia-based prostheses used for tooth-supported or implant-supported single crowns and fixed dental prostheses (FPD).MethodsThe authors conducted a prospective analysis of 562 zirconia core restorations supported by endodontically treated teeth or titanium implant in 276 patients in a general dental private practice, with a follow-up period of 15 years. The study was stopped after patients achieved 15 yrs of follow-up. The study analyzed the failure and complication rates of single and multiple crowns, based on Kaplan Meier analysis.ResultsDuring follow-up period, there were 26 complications and 156 failures. The crown level analysis revealed a cumulative failure rate of 28.33% and complication rate of 8.47% for zirconia crowns after 15 years. The complication rate was found to be higher for titanium implant-supported than for natural teeth-supported crowns. The different types of crown-based failure include: veener fracture 5.01% (N = 29), metal zirconia led to 14.85% (N = 86) loss of retention, and 1.73% (N = 10) loss of crown due to extraction.ConclusionBased on these findings, zirconia core restorations appear to be a reliable long-term solution for crowns and fixed dental prostheses.Clinical relevanceThe study suggests that zirconia restorations can be successfully used for long-term prostheses on natural teeth or implants supported. The study results provide clinicians valuable information when selecting prosthetic restorations material.

Aesthetic outcomes of different materials for delayed, single-tooth restorations for immediately placed implants. A randomized controlled clinical trial

ObjectivesThe aim of this study is to compare the aesthetic outcomes of metal porcelain (C), lithium disilicate (T1) and porcelain-layered zirconium (T2) immediate implant-supported single crowns in the anterior maxilla. Materials and methodsForty-five immediate dental implants were provided for 45 patients that required the extraction of a single tooth in the anterior maxilla. A temporary prosthesis was provided at 8 weeks after placement followed by the final prosthesis at 24 weeks post-implantation. The patients were randomly allocated into 3 groups: 15 patients in the control group (C) received a metal-porcelain restoration, 15 patients (T1) received a lithium disilicate (LD) restoration and 15 patients (T2) received a porcelain-layered, zirconium (Z) restoration. Pink (PES) and White (WES) esthetic scores, radiographic bone levels, periodontal parameters and patient's esthetic satisfaction using a visual analogue scale (VAS) were evaluated at the time of final restoration placement (t0) and at 12-months post-loading (t12). ResultsNo implants were lost during the duration of this study. Statistically significant higher WES and VAS scores (p < 0.05) were recorded in T1 vs C and T1 vs T2 groups respectively. Similar radiographic bone levels and periodontal parameters were recorded in all groups. ConclusionWithin the limitations of this study, it was concluded that T1 restorations provided better WES outcomes when compared to C restorations and better VAS scores when compared to T2 restorations at 12 months post-loading. Besides, different material interphases did not have an impact in PES, bone levels or periodontal parameters. Clinical relevanceThere is limited data comparing aesthetic outcomes of implant supported single crowns made of different ceramic materials based on accepted and comparable indexes and the evaluation of the patient's perspective regarding these aesthetic outcomes.

Static and dynamic stress analysis of different crown materials on a titanium base abutment in an implant-supported single crown: a 3D finite element analysis

BackgroundThis Finite Element Analysis was conducted to analyze the biomechanical behaviors of titanium base abutments and several crown materials with respect to fatigue lifetime and stress distribution in implants and prosthetic components.MethodsFive distinct designs of implant-supported single crowns were modeled, including a polyetheretherketone (PEEK), polymer-infiltrated ceramic network, monolithic lithium disilicate, and precrystallized and crystallized zirconia-reinforced lithium silicates supported by a titanium base abutment. For the static load, a 100 N oblique load was applied to the buccal incline of the palatal cusp of the maxillary right first premolar. The dynamic load was applied in the same way as in static loading with a frequency of 1 Hz. The principal stresses in the peripheral bone as well as the von Mises stresses and fatigue strength of the implants, abutments, prosthetic screws, and crowns were assessed.ResultsAll of the models had comparable von Mises stress values from the implants and abutments, as well as comparable maximum and minimum principal stress values from the cortical and trabecular bones. The PEEK crown showed the lowest stress (46.89 MPa) in the cervical region. The prosthetic screws and implants exhibited the highest von Mises stress among the models. The lithium disilicate crown model had approximately 9.5 times more cycles to fatique values for implants and 1.7 times more cycles to fatique values for abutments than for the lowest ones.ConclusionsWith the promise of at least ten years of clinical success and favorable stress distributions in implants and prosthetic components, clinicians can suggest using an implant-supported lithium disilicate crown with a titanium base abutment.

Monolithic Zirconia Single Crowns Supported by Narrow- or Standard-Diameter Titanium-Zirconia Implants in Posterior Sites: 1-Year Results of a Randomized Controlled Trial.

To compare the prosthetic outcomes of screw-retained monolithic zirconia (Zr) single crowns supported by either narrow-diameter (3.3 mm) or standard-diameter (4.1 mm) tissue-level titanium-zirconia (TiZr) implants in posterior sites. A total of 18 participants, each with a missing molar or premolar tooth requiring an implantsupported single crown, were randomly assigned to either the test or control group. All participants received screwretained monolithic Zr single crowns supported by single tissue-level TiZr implants. Test group participants received narrow-diameter implants (3.3 mm), whereas control group participants received standard-diameter implants (4.1 mm). A modified version of the United States Public Health Service (USPHS) criteria was used to assess the prosthetic outcome across 12 parameters after 1 year of function. Data were analyzed descriptively, and statistical analysis was performed using a statistical software (SPSS, Version 28.0; IBM) with the level of significance set at P < .05. Of the 18 single crowns delivered, 16 were available for review at the 1-year follow-up, including 7 in the test group and 9 in the control group. Patient characteristics and crown site distribution were similar, with no significant differences observed between the two groups (chi-square test; P < .05). There were no crown failures, meaning a crown survival rate of 100% was achieved after 1 year. The prosthetic outcome based on USPHS criteria was comparable between the two groups with no significant differences observed (chi-square test; P < .05). There were 19 prosthetic events in total (10 in the test group and 9 in the control group), with no significant differences between the groups (chi-square test; P < .05). Loss of proximal contact was the dominant event, with a total of eight events (three in the test group and five in the control group). Patient satisfaction after 1 year was high in both treatment groups, with no significant differences detected. Screw-retained monolithic Zr single crowns supported by either narrow- or standard-diameter tissue-level TiZr implants in posterior sites have comparable prosthetic outcomes after 1 year. Long-term results from well-designed trials are still needed to validate the findings of the present study.

Influence of ceramic crown design (translucent monolithic zirconia vs. bilayered) of implant-supported single crowns after mechanical cycling.

This study aimed to assess the influence of translucent monolithic versus bilayered crowns and whether the use of a CoCr base abutments affects the fatigue and fracture resistance of screwed implant-supported single crowns with external connections under mechanical cycling. Fifty specimens were divided into groups: (1) metal-ceramic (MC) crown, (2) veneered zirconia crown (Zr), (3) veneered zirconia crown with a CoCr base abutment (ZrB), (4) monolithic translucent zirconia crown (MZr), and (5) monolithic translucent zirconia crown with a CoCr base abutment (MZrB). Specimens underwent mechanical cycling (5 × 106 cycles; 150 N) evaluating fatigue resistance (number of failures) and those that failed were subsequently subjected to fractographic analyses (stereomicroscope and scanning electron microscope) to evaluate failure location and area, and maximum fracture load was also measured. The failure-related survival rate (100%) and maximum fracture resistance of the MZrB were significantly higher than those of MC and Zr (50%; p < 0.05). There were no significant differences in the failure rate and fracture resistance when a CoCr base abutment was used or not in the translucent monolithic Zr groups (p > 0.05;MZrB vs. MZr). Failure location, with MC crowns' fractures, noted at the screw area (p = 0.043), while all-ceramic crowns were mostly in the cuspid and to failure area, the Zr group had the largest mean (15.55 ± 9.17 mm2) among the groups, significant difference only when compared with MC (1.62 ± 0.81 mm2) (p = 0.025). Translucent monolithic zirconia crowns exhibited significantly higher fatigue and fracture resistance compared with conventional MC and bilayered crowns. The appropriate choice of material and manufacturing technique is crucial for predicting the higher clinical performance of single crowns. Enhanced mechanical resistance in terms of fatigue and fracture resistance can be achieved by replacing MC and bilayered restorations with computer-aided design and computer-aided manufacturing monolithic zirconia.

Single missing molar with wide mesiodistal length restored using a single or double implant-supported crown: A self-controlled case report and 3D finite element analysis.

Based on a self-controlled case, this study evaluated the finite element analysis (FEA) results of a single missing molar with wide mesiodistal length (MDL) restored by a single or double implant-supported crown. A case of a missing bilateral mandibular first molar with wide MDL was restored using a single or double implant-supported crown. The implant survival and peri-implant bone were compared. FEA was conducted in coordination with the case using eight models with different MDLs (12, 13, 14, and 15 mm). Von Mises stress was calculated in the FEA to evaluate the biomechanical responses of the implants under increasing vertical and lateral loading, including the stress values of the implant, abutment, screw, crown, and cortical bone. The restorations on the left and right sides supported by double implants have been used for 6 and 12 years, respectively, and so far have shown excellent osseointegration radiographically.The von Mises stress calculated in the FEA showed that when the MDL was >14 mm, both the bone and prosthetic components bore more stress in the single implant-supported strategy. The strength was 188.62-201.37 MPa and 201.85-215.9 MPa when the MDL was 14 mm and 15 mm, respectively, which significantly exceeded the allowable yield stress (180 MPa). Compared with the single implant-supported crown, the double implant-supported crown reduced peri-implant bone stress and produced a more appropriate stress transfer model at the implant-bone interface when the MDL of the single missing molar was ≥14 mm.

Effectiveness of the full digital flow in the confection of implant-supported single prostheses and comparative analysis between two techniques: with an abutment or direct. Cross-sectional cohort.

With technological advances in Dentistry, the search for more predictable, integrated, and agile planning and treatments increases. In Implantology, despite the digital flow being greatly encouraged, doubts remain about its technical success. Therefore, the aim of this clinical study was to evaluate the effectiveness of the full digital flow using two techniques for the fabrication of implant prostheses: with an abutment or direct to the implant, comparatively evaluating the time required for interproximal adjustment to adapt the crowns, occlusal adjustment, and the need to return to the laboratory for corrections. The sample consisted of 46 patients who underwent the installation of 75 implants, treated at the ILAPEO School of Dentistry surgical clinic. They were all over 18, of both sexes and received implants in single edentulous spaces that required rehabilitation with crowns. These patients were divided into two groups, with Group I (G1), comprising 27 patients (38 implants) who had received abutments at the time of surgery, and Group II (G2) comprising 28 patients (37 implants) who had received healing caps, with 9 patients in common in both groups. In G1, scan bodies adapted to the abutments were used. In G2, they were directly adapted to the implants. The cases were scanned and sent to the laboratory. When the crowns were installed, the prosthesis adjustment data was recorded (in seconds), as well as the need to return to the laboratory for adjustments and corrections. The data from the groups were compared using the Mann-Whitney non-parametric test. There were no statistical differences in terms of occlusal and proximal adjustment time. The need to return prosthetic work to the laboratory was compared between the groups using the chi-squared test. The GraphPad Prism 8 software (San Diego, CA, USA) was used for the statistical analysis, and all tests were applied at a significance level of 5%. Data analysis leads to the conclusion that digital flow made it possible to obtain satisfactory implant-supported single crowns in both groups. No differences were found between the two techniques regarding the time taken to adapt to the mouth and the need to return to the laboratory.

A fully digital workflow to design anterior guidance for an implant-supported single crown using a modified patient-specific motion technique

Current methods for designing anterior guidance of anterior fixed prostheses are either complicated or lack accuracy. The article describes a fully digital workflow to design individualized anterior guidance of an implant-supported single crown by using a modified patient-specific motion technique. The technique aims to optimize the digital occlusal design workflow, thereby improving the occlusal fit and long-term stability of anterior fixed prostheses.

Clinical Outcomes of Tooth- and Implant- Supported Restorations Performed in a University-Based Undergraduate Program After 13 to 15 Years.

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. 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. 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. 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.

Aesthetic Outcome and Patient Perception of Immediate vs. Delayed Loading of Implant-Supported Single Crowns: A Randomized Controlled Trial

ABSTRACT Background: This randomized controlled trial aimed to compare the aesthetic outcome and patient perception of immediate versus DL of implant-supported single crowns. Methods: A total of 60 patients with a single missing tooth were enrolled and randomly assigned to two groups: immediate loading (IL) and delayed loading (DL). Each group consisted of 30 patients with a total of 30 implants. In the IL group, crowns were loaded onto implants immediately after placement, while in the DL group, a healing period of 3 months was observed before crown placement. Aesthetic outcome was assessed using the Pink Esthetic Score (PES) for soft tissue and the White Esthetic Score (WES) for the crown. Patient perception was evaluated through a visual analog scale (VAS) for satisfaction, comfort, and overall experience. Results: The IL group demonstrated comparable aesthetic outcomes to the DL group, with mean PES and WES scores of 10.2 ± 1.5 and 8.7 ± 1.2, respectively, in the IL group, and 10.5 ± 1.3 and 8.5 ± 1.4 in the DL group. Patient perception in terms of satisfaction, comfort, and overall experience was similarly high in both groups, with VAS scores above 8 for each parameter. Conclusion: This randomized controlled trial suggests that both IL and DL of implant-supported single crowns result in favorable aesthetic outcomes and high levels of patient satisfaction.

A two-year prospective study to compare the peri-implant parameters of posterior implant-supported single crowns with and without mesial proximal contact loss

Background/purposeInterproximal contact loss may lead to food impaction and result in subsequently periodontal complications. The purpose of this prospective study was to investigate the peri-implant parameters of posterior implant-supported single crowns (SCs) with and without mesial proximal contact loss after 2 years of follow-up. Material and methodsTwenty-six patients with a total of 40 posterior implant-supported SCs with mesial adjacent natural teeth were observed for 24 months after crown insertion. The mesial proximal contacts were assessed by dental floss, then were classified as tight, weak, and open contacts. The following peri-implant parameters were evaluated, including modified plaque index (MPI), modified gingival index (MGI), and probing depth (PD) were conducted at six sites per tooth (mesiofacail, midfacial, distofacial, mesiolingual, mid-lingual and distolingual) in the 6-, 12-, 18- and 24-month following visits. Furthermore, radiographs were taken regularly in 12- and 24-month recall sections for measuring the marginal bone loss (MBL). ResultsAt 12-month observation, the incidence rates of weak and open contacts were 22.5 % and 12.5 %; whereas after 24 months of clinical service, the rates came up with 12.9 % and 25.6 %, respectively. No significant differences were found between the tight, weak, and open contact groups in the parameters of MPI, MGI, or PD (P > 0.05) at 12- and 24-month follow-up. None of the mean differences of the peri-implant parameters: MPI, MGI, PD and MBL had significant differences between the tight, weak, and open contact groups after 1 and 2 years of clinical service (P > 0.05). ConclusionThe presence of open, weak, and tight mesial proximal contacts had no significant effects on the peri-implant tissue conditions.

Effect of customized abutment taper configuration on bone remodeling and peri-implant tissue around implant-supported single crown: A 3D nonlinear finite element study.

The optimal configuration of a customized implant abutment plays a crucial role in promoting bone remodeling and maintaining the peri-implant gingival contour. However, the biomechanical effects of abutment configuration on bone remodeling and peri-implant tissue remain unclear. This study aimed to evaluate the influence of abutment taper configurations on bone remodeling and peri-implant tissue. Five models with different abutment taper configurations (10°, 20°, 30°, 40°, and 50°) were analyzed using finite element analysis (FEA) to evaluate the biomechanical responses in peri-implant bone and the hydrostatic pressure in peri-implant tissue. The results demonstrated that the rate of increase in bone density was similar in all models. On the other hand, the hydrostatic pressure in peri-implant gingiva revealed significantly different results. Model 10° showed the highest maximum and volume-averaged hydrostatic pressures (69.31 and 4.5mmHg), whereas Model 30° demonstrated the lowest values (57.83 and 3.88mmHg) with the lowest excessive pressure area. The area of excessive hydrostatic pressure decreased in all models as the degree of abutment taper increased from 10° to 30°. In contrast, Models 40° and 50° exhibited greater hydrostatic pressure concentration at the cervical region. In conclusion, the abutment taper configuration had a slight effect on bone remodeling but exerted a significant effect on the peri-implant gingiva above the implant platform via hydrostatic pressure. Significant decreases in greatest and average hydrostatic pressures were observed in the peri-implant tissues of Model 30°. However, the results indicate that implant abutment tapering wider than 40° could result in a larger area of excessive hydrostatic pressure in peri-implant tissue, which could induce gingival recession.

Clinical and Radiographic Evaluation of Short Locking-Taper Implants Supporting Single Crowns in the Posterior Region: A 12-Year Retrospective Study.

Few studies have reported the outcomes of short implants with a follow-up time longer than 10 years. This retrospective study aimed to evaluate the long-term outcomes of the short locking-taper implants supporting single crowns in the posterior region. Patients who received short locking-taper implants (≤ 8 mm) supporting single crowns in the posterior region from 2008 to 2010 were included. The clinical outcomes, radiographic outcomes, and patient satisfaction were recorded. As a result, a total of 18 patients with 34 implants were included. The cumulative survival rate was 91.4% and 83.3% at implant level and patient level, respectively. Tooth brush habit and history of periodontitis were significantly associated with implant failure (P < .05). The median marginal bone loss (MBL) was 0.24 mm (interquartile range: 0.01 to 0.98). Biologic and technical complications occurred in 14.7% and 17.8% implants, respectively. The mean modified sulcus bleeding index and mean peri-implant probing depths were 0.52 ± 0.63 and 2.38 ± 0.79 mm, respectively. All patients were at least quite satisfied, with the majority of patients being fully satisfied (88.9%) with the treatment. Within the limitations of this study, the short locking-taper implants supporting single crowns in the posterior region achieved promising outcomes in the long-term follow-up.

Digitally designed occlusion of an implant-supported crown considering physiological tooth displacement under occlusal loading

Physiological natural tooth displacement under occlusal loading can influence intraoral occlusal contacts. However, gypsum casts and digital scans cannot simulate the physiological tooth displacement under occlusal loading. The occlusal design of the implant-supported crowns has been based mainly on the experience of dental laboratory technicians, lacking accuracy and individualization. Therefore, a digital technique that considers physiological tooth displacement is presented to design the occlusion of implant-supported single crowns.