Single Implant-supported Restorations Research Articles

Fracture resistance of cement-retained lithium disilicate implant-supported crowns: Effect of material used for two-piece abutments.

This study compared the fracture strength of single lithium disilicate implant-supported crowns fabricated on two-piece abutments with various materials: ceramic-reinforced PEEK, zirconia, and lithium disilicate. Thirty-six implants were embedded in acrylic cylinders. A two-piece abutment and a crown were designed following a pre-operation scan for a maxillary left central incisor. The designed crown was used to fabricate 36 lithium disilicate crowns. The designed abutment was used to manufacture 36 abutments from 3 materials, 12 each: (A) zirconia; (B) lithium disilicate; and (C) ceramic-reinforced PEEK. Abutments were surface treated and bonded on the titanium base abutments with resin cement. Then, lithium disilicate crowns were bonded on the assigned abutments. Specimens were then subjected to dynamic loading for 1,200,000 cycles. The fracture strength (N) of the assembly was assessed using a universal testing machine. One-way ANOVA followed by multiple comparison tests was used to evaluate the effect of abutment material on the fracture strength of single implant-supported restorations at a significance of .05. The average fracture strength for the groups with zirconia, PEEK, and lithium disilicate two-piece abutments were 1362N ± 218N, 1235N ± 115N, and 1472N ± 171N, respectively. There was a significant (p < 0.05) difference in fracture strength among the groups. The lithium disilicate group had significantly higher fracture strength (p = 0.0058) than the group with PEEK; however, there was no significant (p > 0.05) difference between the other groups. Two-piece abutments restored with lithium disilicate crowns investigated in the study have the potential to withstand the average physiological occlusal forces in the anterior region.

Influence of Ti-Base-Supported Implant Restoration on Peri- implant Conditions: A Systematic Review and Meta-analysis.

To conduct a systematic review and meta-analysis to examine the impact of titanium (Ti) base-supported single-implant restorations on peri-implant conditions. 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. Data from this study revealed that the Ti-basegroup 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. The use of a Ti-base in a single implant-supported restorationis 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.

Single posterior implant-supported restorations fabricated using a scannable healing abutment versus a conventional scan body: A randomized controlled trial

Statement of problemThe use of a scannable healing abutment is a convenient option for fabricating implant-supported restorations (ISRs) with a digital workflow; however, clinical studies evaluating prosthetic efficacy are lacking. PurposeThe purpose of this randomized controlled trial was to investigate the prosthetic efficacy of definitive posterior single ISRs fabricated after scanning using a scannable healing abutment-scan peg (SHA-SP) in comparison with a conventional scan body (CSB). The time for data acquisition, quality of proximal and occlusal contacts, and relative occlusal force of ISRs were measured. Material and methodsTwenty-four participants eligible for single ISRs to replace the mandibular first molar with adjacent and antagonist teeth present were randomly allocated to either a study group (n=12) receiving ISRs after intraoral scanning using an SHA-SP or a control group (n=12) receiving ISRs after intraoral scanning using CSB. During the surgical procedure, a prefabricated contoured scannable healing abutment was screwed to the implant in the SHA-SP group, while a custom-made healing abutment was used in the CSB group. After a healing period of 3 months, an intraoral scan was made, and the duration of data acquisition was recorded. The ISRs were milled from zirconia and evaluated for the quality of proximal and occlusal contacts using dental floss and shim stock, respectively. The relative occlusal forces of the ISRs and their contralateral natural teeth were measured using a digital occlusal analyzer. Statistical analysis was done using an independent sample t test for quantitative variables and a Pearson chi-squared test for qualitative variables between the tested groups (α=.05). ResultsThe direct digital workflow using SHA-SP was statistically less time consuming than the CSB (P<.001). The 2 groups were statistically similar regarding the quality of the proximal contacts (P=.281) or occlusal contacts (P=.307) and the relative occlusal forces of ISRs (P=.315). The relative occlusal forces of the ISRs in both groups were significantly lower than those of their contralateral natural teeth (P<.001). ConclusionsDirect digital workflow using SHA-SP was more rapid, saving clinical chairside time, and produced proximal and occlusal contacts of comparable quality with those obtained with CSB. The relative occlusal forces of ISRs in both workflows were lower than their contralateral natural teeth.

A novel technique for retrieval of cement-retained crown from an implant abutment and converting it into a combination prostheses

Dental implant restoration is known to be a widely accepted treatment modality for the replacement of missing teeth and the restoration of masticatory function. Abutment screw loosening is one of the most common causes of failure in single implant-supported restorations, next to loss of osseointegration. Moreover, cement-retained implant-supported prostheses are infamous for their lack of predictable retrievability compared to screw-retained implant-supported prostheses. Management and retrieval of loosening screws are challenging, and this clinical report discusses the procedure for retrieving prosthesis from the abutment of the mandibular molar tooth with minimal damage to the existing restoration, making it possible to be reused.

Influence of the dental arch and number of cutting-off and rescanning mesh holes on the accuracy of implant scans in partially edentulous situations

ObjectivesTo evaluate the influence of the dental arch and cutting-off and rescanning procedures on the accuracy of complete-arch implant scans in partially edentulous arches. Material and methodsA maxillary and a mandibular partially edentulous typodont with implant abutment analogs placed in the right and left first molar and right central incisor sites were digitized to create reference models by using an industrial optical scanner (7 Series Desktop Scanner; Dentalwings). Two experimental groups were scanned using an intraoral scanner (IOS) (TRIOS 4; 3Shape A/S): the Maxillary group (Mx) and the Mandibular group (Mb). Four subgroups were generated depending on the number of rescanned mesh holes: No holes (Mx-G0, Mb-G0), 1 hole (Mx-G1, Mb-G1), 2 holes (Mx-G2, Mb-G2) and 3 holes (Mx-G3, Mb-G3). A 3-dimensional metrology software (Geomagic Control X; 3D Systems) was used to measure the difference between the reference and the experimental scans computing the root mean square (RMS) error calculation. Two-way ANOVA and a post-hoc Tukey test were used to analyze the trueness data (α=0.05). Levene test was used to evaluate the prevision (α=0.05). ResultsThe Mx group obtained a trueness mean value of 54 ± 17 µm and a mean precision value of 54 ± 17 µm, while the Mb group presented a trueness mean value of 67 ± 23 µm and a mean precision value of 66 ± 22 µm. The Mx group demonstrated significantly better trueness than the Mb group (P<.001). The G0 and G1 subgroups had the highest trueness values among the subgroups tested. No significant difference was observed between G0 and G1, G1 and G2, and G2 and G3 subgroups in trueness and precision. However, the G0 had significantly better trueness and precision values compared to G2 and G3 subgroups. In addition, the G1 had significantly better trueness values than the G3 subgroup. However, the Levene test revealed no difference in the precision mean values among the subgroups tested. ConclusionsImplant scanning trueness was affected by the dental arch and the number of rescanned mesh holes using the IOS tested. A higher number of rescanned mesh holes decreased the scanning trueness. The stitching algorithm of the IOS software tested after the mesh hole scan demonstrated a significant error, especially when multiples mesh holes are involved in the same arch. Clinical significanceGiven that cutting-off and rescanning techniques can reduce trueness, clinicians should consider whether these techniques are necessary in complete digital workflows. This is particularly important when fabricating multiple single implant-supported restorations in the same arch.

Comparative Analysis of Sensory Responses from Dental Implants vs Natural Teeth: An In Vivo Study

Purpose: To compare subjects' sensory responses to horizontal and vertical forces on tooth- and implant-supported restorations. Materials and Methods: In this prospective study, three protocols simulating the horizontal or vertical forces that occur during mastication were used to obtain subjective responses from subjects. These protocols included the measurement of horizontal force intensity during excursive movements and the identification of initial contact during guided and free vertical closure. Responses were recorded using a 1- to 10-point visual analog scale (VAS) and/ or monitored with electromyography (EMG) and Tekscan. Results: The study included 30 patients with a single implant-supported restoration (ISR) with a contralateral tooth-supported restoration (TSR). For horizontal forces similar to those of mastication (0.6 N), subject VAS scores were similar for both ISRs and TSRs at 6.3 vs 6.1, respectively. At reduced forces (0.2 and 0.4 N), subject responses were greater for the TSR at 3.4 and 5.4, respectively, as opposed to 1.2 and 2.6 for ISR, respectively (P < .01). During vertical guided closure (Test 1) at 25% of maximum bite force (MBF), subjects were more successful at correctly identifying initial contact of TSRs at a rate of 12 out of 17, compared to ISRs, which achieved a rate of 4 out of 13 (P < .1). In vertical free closure (Test 2), subject responses for the correct identification of initial contact at 50% MBF were similar for both TSRs and ISRs at 13 out of 17 and 9 out of 13, respectively. However, comparing the correct responses for subjects whose initial contacts were ISR showed a significant improvement in correct answers from Test 1 to Test 2, from 4 out of 13 correct to 9 out of 13 correct (P < .05). Conclusion: While the mechanism is not clear, subjects' ability to discern the horizontal and vertical forces at levels comparable to mastication appear similar between TSRs and ISRs.

Outcomes of bio-esthetic single implant-supported restorations after peri-implant soft tissue conditioning with two prosthetic techniques: A 1-year randomized clinical trial.

Providing a definitive restoration with an emergence profile matching that of the contralateral or extracted tooth should result in an esthetic peri-implant soft tissue contour. Whether a custom healing abutment improves the outcome of a bio-copied definitive restoration compared with a stock abutment is unclear. The purpose of this 1-year randomized clinical trial was to evaluate the peri-implant soft and hard tissues related to bio-esthetic single implant-supported restorations having a contralateral tooth-matching restorative emergence profile after peri-implant soft tissue conditioning with either custom or stock healing abutment for patients indicated for immediate implant placement. Twenty-four participants indicated for immediate implant placement in the maxillary esthetic zone received bio-esthetic single implant-supported restorations after peri-implant soft tissue conditioning with either a custom healing abutment (n=12) or a stock healing abutment (n=12). The pink and white esthetic score (PES-WES) was evaluated 6 and 12 months after implant placement. Peri-implant bone changes were measured with cone beam computed tomography (CBCT) scans at the same intervals. The PES-WES showed significant difference between the 2 groups at 6 and 12 months. The CBCT scans did not show significant difference between the 2 groups. The use of the bio-esthetic concept for immediate single implant placement achieved successful esthetic restorations after conditioning the peri-implant tissues using either custom or stock healing abutments. However, the use of custom healing abutments was associated with higher PES-WES values in comparison with the use of stock healing abutments.

Immediate vs. Delayed Placement of Immediately Provisionalized Self-Tapping Implants: A Non-Randomized Controlled Clinical Trial with 1 Year of Follow-Up.

This study aimed to examine the clinical and esthetic outcomes of immediately provisionalized self-tapping implants placed in extraction sockets or healed edentulous ridges one year after treatment. Sixty patients in need of a single implant-supported restoration were treated with self-tapping implants (Straumann BLX) and immediate provisionalization. The implant stability quotient (ISQ) and insertion torque were recorded intraoperatively. After one year in function, the implant and prosthesis survival rate, pink esthetic score (PES), white esthetic score (WES), and marginal bone levels (MBL) were assessed. Sixty patients received 60 self-tapping implants. A total of 37 implants were placed in extraction sockets and 23 in edentulous ridges, and then all implants were immediately provisionalized. All implants achieved a high implant stability with a mean insertion torque and ISQ value of 58.1 ± 14.1 Ncm and 73.6 ± 8.1 Ncm, respectively. No significant differences were found between healed vs. post-extractive sockets (p = 0.716 and p = 0.875), or between flap vs. flapless approaches (p = 0.862 and p = 0.228) with regards to the insertion torque and ISQ value. Nonetheless, higher insertion torque values and ISQs were recorded for mandibular implants (maxilla vs. mandible, insertion torque: 55.30 + 11.25 Ncm vs. 62.41 + 17.01 Ncm, p = 0.057; ISQ: 72.05 + 8.27 vs. 76.08 + 7.37, p = 0.058). One implant did not osseointegrate, resulting in an implant survival rate of 98.3%. All implants achieved PES and WES scores higher than 12 at the 1-year follow-up. The clinical use of newly designed self-tapping implants with immediate temporization was safe and predictable. The implants achieved a good primary stability, high implant survival rate, and favorable radiographic and esthetic outcomes, regardless of the immediate or delayed placement protocols.

Numerical and Experimental Evaluation of Biomechanical Behavior of Single Implant-Supported Restorations Based on Angled Abutments with Different Gingival Heights

The effect of angle abutment on the stress distribution of bone tissue around implant is not clear. Using abutments with different gingival height (GH) may cause changes in the stress distribution of the implant and implant-bone interface. This study aims to investigate whether angled abutments with varied GH have a significant effect on stress distribution of surrounding bone and the biomechanical behavior of the implant system. Three implant-supported restoration models were designed by changing the angled abutment GH (1 mm, 3 mm and 5 mm). Force of 200N was applied on the crown surface at 45° to the long axis of the implants. The biomechanical performance of the restorations (including implants and angled abutments) and stress distribution pattern were evaluated by finite element analysis (FEA). Results showed that angled abutments with larger GH resulted in increased stresses on the implant and implant-bone interface.

Digital Implant Dentistry Predoctoral Program at University of Kentucky.

This report describes the predoctoral comprehensive digital implant dentistry program at the University of Kentucky, College of Dentistry (UKCD). UKCD has implemented a digital dentistry workflow in the dental curriculum for predoctoral and graduate programs since 2018. Digital implant dentistry education involves using cone beam computed tomography (CBCT) for diagnosis and treatment planning, intraoral scanner for digital impression, and treatment planning software to plan for single implant-supported restorations and implant-retained mandibular overdenture cases. The laboratory components include virtual designing of a surgical guide and using three-dimensional printing to fabricate a fully guided surgical template for implant placement procedures for the patient. In the last 3 years, including the COVID year, a total of 294 implants have been placed by dental students. Unfortunately, 6 implants failed in the early healing time due to infection, with an overall success rate of 98%. These treatment outcomes are very favorable compared with published literature.

Analysis of fractured dental implant body from five different implant systems: a long-term retrospective study

The aim of this study was to perform an analysis of the incidence of implant body fracture and to identify possible risk factors. A long-term follow-up retrospective evaluation of 3477 patients who received 8588 implants from five implant systems was performed. Overall, 2810 patients who received 7502 implants, with an average follow-up of 6.9 years, were included in the analysis. The overall body fracture rate was 0.49% (37/7502), among which 32.4% (12/37) were implants with a reduced diameter. The estimated cumulative fracture rate was 1.24%. Fractures were observed in two patients with three Brånemark implants, 13 patients with 15 Nobel Replace implants, eight patients with eight Camlog implants, eight patients with 11 Ankylos implants, and none of the patients with Thommen implants. Most fractures occurred in the molar region (29/37) and in single implant-supported restorations (30/37). The results showed significant differences between splinted and unsplinted restorations (P = 0.005) and between regular and narrow diameter implants (P = 0.009). Within the limitations of this retrospective analysis, a narrow implant diameter is a potential risk factor for implant body fracture in the posterior region. Furthermore, unsplinted restorations appear to be associated with a higher rate of implant fracture.

Influence of buccal emergence profile designs on peri-implant tissues: A randomized controlled trial.

The prosthetic emergence profile design might be an important factor in postsurgical mucosal recession etiology. Therefore, a restorative buccal emergence profile designed correctly might reduce gingival margin recession. To compare the marginal gingival level and the width/height (W/H) ratio between two profile configurations of single implant-supported restorations at molar sites. Twenty-one patients requiring a single mandibular molar tooth replacement with supracrestal mucosal thickness ≥2 mm were recruited and randomly assigned to a prosthesis buccal emergence profile design based on the buccal mucosal W/H ratio (Test Group) or maintained the original emergence profile of the healing abutment (Control Group). Assessments were made before delivery of the definitive restoration (T0), at prosthesis placement (T1), one (T2), and 12 (T3) months after loading. The gingival margin level change (△GM), initial emergence angle, buccal mucosal W/H ratio, marginal bone loss (MBL), implant failure, and complications were assessed. The gingival recession in the test group (0.13 ± 0.32 mm) was significantly lower than in the control group (0.63 ± 0.38 mm) at T3 (p=0.006). The initial emergence angle in the test group (31.4 ± 7.22 degrees) was significantly lower than the control group (40.0 ± 7.60 degrees) (p=0.025). The W/H ratio in the test group at T2 was significantly higher than at T0 but remained stable thereafter. The W/H ratio presented a continued rising trend in the control group. When the initial supracrestal soft tissue thickness was ≥2 mm, a restorative emergence profile based on the W/H ratio significantly reduced gingival margin recession. An emergence angle of 32.4 degrees showed better behavior in maintaining the gingival margin than 40 degrees. ChiCTR190002210.

Marginal Bone Loss around Implants with Internal Hexagonal and Internal Conical Connections: A 12-Month Randomized Pilot Study.

The aim of this study was to analyze the differences in terms of the marginal bone level (MBL) around implants with either an internal conical or an internal hexagonal implant–prosthesis connection. A randomized clinical trial included patients in need of a single implant-supported restoration. The implant–prosthesis connection was either internal conical or internal hexagonal while maintaining the same type of implant macro- and microarchitecture. Clinical and radiographical variables were registered up to 12 months of follow-up, including MBL. A total of 30 patients were included in the study. The main outcome variable, MBL 12 months after prosthesis delivery, was statistically different in both groups: −0.25 (0.12) vs. −0.70 (0.43) (conical vs. hexagonal; p = 0.033). Differences were also observed at the 3- and 6-month follow-up visits as well as for the MBL change from prosthesis delivery to the 12-month follow-up (−0.15 (0.13) vs. −0.56 (0.44); conical vs. hexagonal; p = 0.023). Correlations between MBL around the implants and radiographic measurements on the adjacent teeth, buccal bone to implant, tissue thickness or keratinized tissue were not significant neither globally nor when analyzed independently by group. In view of such results, it can be concluded that single-unit restorations with internal hexagonal-connection implants induce higher marginal bone loss after 12 months of follow-up from prosthesis delivery than internal conical-connection implants.

The ability to screw-retain single implant-supported restorations in the anterior maxilla: A CBCT analysis

Statement of problemEvidence to validate the routine use of angled screw-channel abutments in the anterior maxilla is sparse. If properly planned, they might provide surgical and prosthetic benefits. PurposeThe purpose of this observational study was to determine the prevalence of digitally placed implants in the anterior maxilla that would allow screw-retained implant-supported restorations with either a straight or an angled screw-channel abutment. Material and methodsTwo hundred cone beam computed tomography (CBCT) scans met the inclusion criteria for retrospective analysis and digital implant planning. Virtual implants were planned for randomly selected anterior maxillary teeth by using the anatomic crown and root position. Virtual abutments of varying angulation were attached to the implants to determine the ability to screw retain a restoration with either a straight or an angled screw-channel abutment. ResultsOne hundred fifty-two (76%) sites required an angled screw-channel abutment to enable screw retention. Forty-eight (24%) sites allowed screw retention with a straight abutment. The percentage of implants requiring angled or straight abutments varied significantly among anterior teeth (P<.005). One hundred nine (71.7%) angled screw-channel abutment sites required a 5-degree abutment, 41 (26.9%) required a 10-degree abutment, and 2 (1.3%) required a 15-degree abutment. Among the anterior teeth, lateral incisors presented a greater need for angled screw-channel abutments. None of the implants in the present study needed cement-retained restorations. ConclusionsAngled abutments allowed for screw-retained restorations on digitally planned implants in the anterior maxilla. The required angular correction to a screw-retained restoration was ≤15 degrees. Screw-retained restorations were frequently achievable (76%) with the use of angled screw-channel abutments or with straight abutments (24%), and lateral incisors presented a greater need for angled screw-channel abutments.

A clinical study comparing digital scanning and conventional impression making for implant-supported prostheses: A crossover clinical trial

Statement of problemThe impact of discrepancies between casts produced from digital scans and conventional impressions on the clinical performance of definitive restorations has not been fully investigated. PurposeThe purpose of this crossover clinical trial was to evaluate the clinical performance of single implant-supported restorations fabricated with the digital scanning technique and computer-aided design and computer-aided manufacturing (CAD-CAM) casts compared with the conventional impression technique and gypsum casts in terms of efficiency, accuracy, and participant preference. Material and methodsThirty participants underwent conventional impressions and digital scans of a single implant-supported restoration. Two crowns were fabricated for the same implant with each technique. The time taken for each procedure was recorded. After the accuracy and efficiency analysis of both crowns, the better crown was delivered. A questionnaire was used to assess participant preference and comfort with the techniques. The Wilcoxon signed-rank test was used to compare the time measurements, and multiple comparisons were performed using the Bonferroni method. The chi-square test was used to compare the implant locations of delivered crowns (α=.05). ResultsThe total time for the conventional impression technique was 14.16 minutes, while that for the digital scanning technique was significantly less at 11.28 minutes (P<.001). Remake times were 0.56 minutes for conventional impressions and 2.27 for digital scans, also significantly different (P<.001). The adjustment time taken in delivering the crowns was 4.35 minutes for conventional impressions and 3.78 minutes for conventional impressions, which was not statistically significant (P=.940). Of the crowns chosen for delivery, 46.7% were from conventional impressions and 53.3% from digital scans. Participants preferred the digital scanning technique (89%) to the conventional impression technique (11%). ConclusionsThe digital scanning technique was more efficient than the conventional impression technique for single implant-supported restorations. Digital scans and CAD-CAM implant casts had accuracy comparable with that of conventional impressions and gypsum casts. Most participants preferred digital scans to conventional impressions.

Influence of Immediate Implant Placement and Provisionalization with or without Soft Tissue Augmentation on Hard and Soft Tissues in the Esthetic Zone: A One-Year Retrospective Study.

The purpose of this clinical research was to evaluate peri-implant marginal changes around immediate implants placed either with the application of SCTG or XCM or without soft tissue grafting. A total of 48 patients requiring a single implant-supported restoration in the anterior jaw were selected for inclusion. Three surgical procedures were performed, as follows: type 1 implant with subepithelial connective tissue graft (SCTG), type 1 implant with xenogenic collagen matrix (XCM), and type 1 implant without soft tissue augmentation (NG) (control group). The marginal change of peri-implant soft tissue, facial soft tissue thickness (FSTT), peri-implant health status, esthetics, and patient satisfaction were assessed at one year after surgery. All of the placed implants showed a survival rate of 100%. No significant differences in FSTT were recorded between the SCTG group and the XCM group after treatment (P > 0.05), while the NG group presented a significant difference (P < 0.05). Patients in the NG group lost significantly more in the buccal marginal level than did patients in the SCTG group and those in the XCM group (P < 0.05). The favourable success rate recorded in all groups confirmed immediate tooth replacement as a choice of treatment for a missing anterior single tooth. The NG group presented significant changes of FSTT and buccal marginal level, while XCM constituted a viable alternative to SCTG.

Spectrophotometric and Visual Evaluation of Maxillary Anterior Implant Crowns and Peri-implant Soft Tissues: A Retrospective Study.

To visually and spectrophotometrically determine the differences in the shades of maxillary anterior implant crowns and peri-implant soft tissues compared to a natural teeth control group. A total of 44 patients restored with single implant-supported restorations were assessed after at least 6 months in function. Images of the implant crowns, peri-implant soft tissues, and their controls were captured using a spectrophotometer (SpectroShade Micro, Medical High Technologies). Visual assessment of shade differences between the implant crowns and peri-implant soft tissues and their controls were performed by the patients and four dental professionals using a visual analog scale (VAS). Analysis of variance was applied to detect differences between groups. The mean color differences (ΔE) between the implant crowns and peri-implant soft tissues and their respective controls were 4.8 ± 2.6 and 6.6 ± 2.7, respectively. A significant difference (P = .025) in mean ΔE values was observed only at the cervical third of the implant crowns. The patient group showed the highest mean VAS scores for shade matching of the implant crowns (8.4 ± 1.2) and peri-implant soft tissues (7.8 ± 1.6) with their respective controls. Spectrophotometric analysis showed significant shade differences at the cervical third of the implant crowns. The patients were more satisfied with the shade matching of their implant restorations than the dental professionals.

Comparative clinical evaluation of esthetic parameters of immediately provisionalized implants in the esthetic zone with their natural counterparts

Background: An anterior single implant-supported crown restoration in the maxillary anterior region must meet a particularly high standard of esthetic quality. The standard of care for edentulous space in esthetic zone therefore would be the placement of an implant with immediate provisionalization. Aims and Objecectives: The aim of this study is to evaluate the esthetic parameters of immediately provisionalized implants in the esthetic zone and compare patients opinion with blinded clinicians opinion of the outcome of esthetics of implant in esthtic zone. Materials and Methods: In our study, we placed 10 maxillary anterior single-tooth implants in fully healed maxillary anterior sites in esthetic zone. All the implants were provisionalized within 24 hours. Zirconia prosthesis was delivered as definitive prosthesis after three months of implant placement. The esthetic zone was photographed three months after delivering the definitive prosthesis. The esthetic outcome was then evaluated objectively using Pink Esthetic Score (PES) and White Esthetic Score (WES) by a blinded clinician. In addition, we used a triple score technique Visual Analogue Scale(VAS) wherein the patients commented on the soft tissue, prosthetic as well as the overall esthetic outcome. Results: A mean PES of 9.2± 1.03 and a mean WES of 8.7± 1.16 recorded showed an acceptable peri-implant soft tissue outcome and an acceptable prosthetic outcome respectively. The statistical analysis revealed statistically significant correlation between patients' esthetic perception and dentists' perception of the anterior tooth. Conclusion: The PES/WES is an objective tool in rating the esthetics of implant supported single crowns and adjacent soft tissues. Orthodontists were the most critical observers, while periodontists were more generous than other observers. The statistical analysis revealed a statistically significant correlation between patients' esthetic perception and dentists' perception of the anterior tooth.

Therapeutic alternatives for addressing pink esthetic complications in single-tooth implants: A proposal for a clinical decision tree.

Esthetic complications in implant therapy today represent a clinical challenge, when the aim is to overcome the sequelae and obtain a pleasing result. The current scientific literature about this topic is scarce and often based on case reports and the personal opinions of clinicians. The aim of this article is to introduce a decision tree for diagnosis and treatment of complications, focusing on the pink esthetic of single-tooth implants and based on three diagnostic pillars (3D implant position, peri-implant hard-tissue anatomy, and peri-implant soft-tissue anatomy). Different shortcomings have been identified for each of the three diagnostic areas. Following this tree, the article proposes treatment alternatives including soft- and hard-tissue reconstruction, implant submergence, orthodontic extrusion, and implant extraction in order to help clinicians establish a logical therapeutic sequence. Guidelines for adequate diagnosis and management of single implant-supported restorations with compromised esthetics is mandatory when attempt to overcome shortcoming in the pink esthetic result.

Analysis of risk factors of 19 fractured implants

Objective: To analyze the incidence and possible risk factors of 19 fractured implants out of 8 468 implants in 3 184 cases. Methods: During the 22-year clinical practice, clinical records of 18 patients with 19 fractured implants in 3 184 cases with 8 468 implants were analyzed to determine the following factors: location of the fractured implants, prosthodontics option, date of implant fracture, dimensions of fractured implants, complications prior to implant fracture and parafunctional habit. An evaluation of fractured implants was performed to identify possible factors that may predispose an implant to a higher risk of fracture. Results: Overall, the average duration of service of the implants was (7.0±4.5) years. Implant fracture occurred in 7 Camlog implants, 7 Nobel replace implants, 3 Ankylos implants and 2 Brånemark implants. No Thommen implant fractures were recorded. Amongst the 19 fractured implants, 8 occurred at the thinnest wall portion of the implant neck, 8 at the end of screw and 3 at the self-tapping thread region. All fractures were observed after functional loading. Furthermore, 9/19 (47.4%) of fractures occurred in the maxilla, indicating similar incidence rates in both arches (P=0.065). Most of fractures (16/19) occurred in the molar region and 18/19 in single implant-supported restorations. Totally 17 cases had received metal occlusal restorations. In 6 cases (35.5%), previous bone destruction apically extending to the level of implant fracture was documented before any clinical signs of fracture. Three fractured implants were removed and simultaneously re-implanted with larger-diameter implants, while the rest of the cases were left to heal, followed by a second-stage surgery. Conclusions: Within the limitation of this analysis, the study demonstrated that appropriate implant-abutment connection design, implant diameter, prosthetic strategy and bone resorption are crucial to the long-term performance of implants. There is no significant difference of fractures rates in both archs.