RESUMEN

Aims: The study aimed to evaluate biological, mechanical, and patient reported parameters associated with ASC abutments and MU abutments for the fabrication of screw retained implant crowns in the anterior esthetic zone. Setting and Design: For the study, 20 patients were selected and implants were placed within the constraints of prosthetic envelope. Later, the screw retained crown was fabricated. Materials and Methods: Biological parameters (including implant survival rate, marginal bone levels using cone beam computed tomography, and soft tissue assessment using periodontal indices) were measured at the time of crown placement and 1 year follow up. Mechanical parameter (screw loosening) was calculated using removal torque loss (RTL) values obtained at the time of crown placement and 1 year follow up. Patient reported parameters were evaluated using a questionnaire at 1 year follow up. Statistical Analysis Used: All data were tabulated, statistically analyzed, and compared using SPSS version 23 IBM Corporation, Armonk, NY, USA. Results: Implant survival was found 100% in both the groups. The marginal bone level reduced considerably in both the groups from baseline to 1 year follow up. The MU abutment group had slightly less marginal bone loss than the ASC abutment group. Additionally, there was no statistically significant difference between the two groups' periodontal indices at baseline and 1-year follow-up values. At baseline, the RTL value was substantially lower (P <0.003) in the ASC abutment group than in the MU abutment group, however at the 1-year follow-up, there was no statistically significant difference in RTL or screw loosening between the two groups. Patient-reported data showed no statistically significant difference. Conclusion: Within the constraints of this study, it was suggested that both ASC and MU abutments provide equally promising results in terms of biological, mechanical, and patient-reported parameters in the anterior esthetic region for single screw-retained crowns.

Asunto(s)

RESUMEN

OBJECTIVE: The objective of this study is to compare the clinical efficacy of angulated screw channel abutment applied in the anterior area with regular cemented crowns. MATERIALS AND METHODS: Forty-eight patients were included and divided into two groups: the angulated screw channel group (ASC) and regular cemented group (RC) in this retrospective cohort study. The evaluation criteria included implant/restoration survival rate, keratinized mucosa width (KMW), bleeding on probing rate (BOP%), probing depth (PD), pink aesthetic score (PES), mechanical/biological complications, emergence angle (EA), the site of implant axis penetrate (SA), marginal bone loss (MBL), and buccal bone thickness (BBT) at 0 mm, 1 mm, 3 mm, 5 mm below the implant shoulder were evaluated in immediate postoperative (T0) and follow-up period (T1). RESULTS: This retrospective cohort study included a total of 48 patients, with a mean 32 months follow-up period range from 12 months to 70 months. The study did not find any cases of implant failure or restoration failure. EA was significantly wider in the RC group than ASC group (RC: 33.53° ± 8.36° vs ASC: 27.43° ± 8.08°, p = 0.016*). While the BOP% was statistically significant higher in the RC group than ASC group (RC: 28.35% ± 22.92% vs ASC: 13.18% ± 20.00%, p = 0.027*). No significant differences were observed in the other measurements of comparison. CONCLUSION: Within the limitations of the study, angulated screw channel (Nobel Biocare) crowns might allow the implant axis aim at incisal edge to reduce the emergence angle in the anterior area and benefit the soft-tissue during the 12-70 months follow-up period.

Asunto(s)

RESUMEN

This in vitro experiment aimed to understand the difference in preload acting on an abutment screw under different angles of angulated screw-retained crown and the performance after cyclic loading. In total, thirty implants with angulated screw channel (ASC) abutments were divided into two parts. The first part consisted of three groups: a 0° access channel with a zirconia crown (ASC-0) (n = 5), a 15° access channel with a specially designed zirconia crown (sASC-15) (n = 5), and a 25° access channel with a specially designed zirconia crown (sASC-25) (n = 5). The reverse torque value (RTV) was measured at 0° for each specimen. The second part consisted of three groups: a 0° access channel with a zirconia crown (ASC-0) (n = 5); a 15° access channel with a zirconia crown (ASC-15) (n = 5), and a 25° access channel with a zirconia crown (ASC-25) (n = 5). The manufacturer's recommended torque was applied to each specimen, and baseline RTV was measured before cyclic loading. Each ASC implant assembly was cyclically loaded at 0 to 40 N with 1 million cycles at 10 Hz. RTV was measured after cyclic loading. Kruskal-Wallis test and Jonckheere-Terpstra test were used for statistical analysis. All specimens were examined under a digital microscope and scanning electron microscope (SEM) to observe the wear of the screw head before and after the whole experiment. A significant difference in the different percentages of straight RTV (sRTV) between the three groups was found (p = 0.027). The angle of ASC to the different percentages of sRTV showed a significant linear trend (p = 0.003). No significant differences were found in RTV difference after cyclic loading among the ASC-0, ASC-15, and ASC-25 groups (p = 0.212). The ASC-25 group had the most serious degree of wear based on a digital microscope and SEM examination. The ASC angle will affect the actual preload acting on a screw: the larger the ASC angle, the smaller the preload. The performance of the angled ASC groups in RTV difference was comparable to that of 0° ASC after cyclic loading.

RESUMEN

The use of dental implants in pediatric patients may create unique complications. A 38-year-old patient presented with a mobile, cement-retained implant crown due to an abutment screw loosening. The maxillary right central incisor implant was placed when the patient was 10 years old. Pus discharge from the peri-implant sulcus was observed. The mucosal margin of the implant was at the level of the mucogingival junction of neighboring teeth. Radiographically, the platform of the implant appeared to be at the level of the apical third of the adjacent roots. After removing the existing implant-retained crown, the inflamed peri-implant tissue covering the implant platform was removed and the stability of the implant was confirmed. A new screw-retained implant crown was made using an angulated screw channel to correct the labiopalatal angulation of the implant and allow for retrievability. Pink porcelain was used to match the mucosal margin of the implant crown to that of the maxillary left central incisor. This case report highlights the risk of implant placement in pediatric patients and agrees with previous reports that implants should be delayed until growth is complete.

Asunto(s)

RESUMEN

OBJECTIVES: To evaluate the clinical effect of integrated angulated screw channel (ASC) abutment crown in implant-supported rehabilitation of the aesthetic area. METHODS: Sixteen patients who received single implant-supported rehabilitation using integrated ASC abutment crown in the aesthetic area were included in the study. After one-year follow-up, the cumulative survival rate, aesthetic effectiveness, bone resorption around implants, and patient satisfaction were analyzed through periapical film, clinical examination, and the visual analog scale (VAS). RESULTS: The implant cumulative survival rate of the integrated ASC abutment crown in the implant-supported rehabilitation of the aesthetic area was 100%. The average pink esthetic index scores reached 9.5, and the white esthetic index scores reached 9.4. The mean marginal bone loss of implants was (0.439±0.123) mm at the mesial side and (0.341±0.118) mm at the distal side. The average VAS satisfaction score was 8.9, which showed that all patients were satisfied with the final restorative effect. CONCLUSIONS: Using integrated ASC abutment crown for implant restoration is an ideal implant restoration design in the aesthetic zone and can be applied clinically.

Asunto(s)

RESUMEN

OBJECTIVES@#To evaluate the clinical effect of integrated angulated screw channel (ASC) abutment crown in implant-supported rehabilitation of the aesthetic area.@*METHODS@#Sixteen patients who received single implant-supported rehabilitation using integrated ASC abutment crown in the aesthetic area were included in the study. After one-year follow-up, the cumulative survival rate, aesthetic effectiveness, bone resorption around implants, and patient satisfaction were analyzed through periapical film, clinical examination, and the visual analog scale (VAS).@*RESULTS@#The implant cumulative survival rate of the integrated ASC abutment crown in the implant-supported rehabilitation of the aesthetic area was 100%. The average pink esthetic index scores reached 9.5, and the white esthetic index scores reached 9.4. The mean marginal bone loss of implants was (0.439±0.123) mm at the mesial side and (0.341±0.118) mm at the distal side. The average VAS satisfaction score was 8.9, which showed that all patients were satisfied with the final restorative effect.@*CONCLUSIONS@#Using integrated ASC abutment crown for implant restoration is an ideal implant restoration design in the aesthetic zone and can be applied clinically.

Asunto(s)

RESUMEN

PURPOSE: The aim of this study was to investigate the effect of implant screw channel angulation on the fracture resistance of zirconia abutments without artificial aging. MATERIALS AND METHODS: Ten implant replicas were embedded in a jig of autopolymerizing acrylic resin. Using a surveyor and a metallic platform, the implant replicas were mounted centrally and with an angulation of 30°. A maxillary left central incisor crown was fabricated from pattern resin and scanned. The digital design of a monolithic zirconia implant abutment-crown was completed using a 3D imaging software. For all specimens of this group (ASC25 ), the screw channel was positioned at 25° to the lingual. Following fabrication, the samples were attached onto the embedded implant replicas and manually torqued to 35 Ncm as recommended by the manufacturer. The monolithic zirconia implant abutment-crowns were mounted in a metallic platform, positioned perpendicular to the indenter, and subjected to loading until failure. Crosshead speed was set at 0.5 mm/min for the universal testing machine. Data from a similar in vitro study where straight zirconia custom abutments (ASC0 ) were subjected to static load until failure was used as a control group. An unpaired Student's t-test was used to determine if fracture resistance based on load at failure and maximum load in each group were significantly different from each other (ASC25 vs ASC0 ). Statistical significance level was inferred at p ≤ 0.05 RESULTS: Group ASC25 fractured at a mean (SD) load of 215.49 (47.10) N and a mean (SD) maximum load of 420.50 (17.18) N. Group ASC0 fractured at a mean (SD) load of 534.04 (133.77) N and a mean (SD) maximum load of 762.69 (109.59) N. The difference was statistically significant for both mean load and mean maximum load at failure (p ≤ 0.05). The survival rate of 0° zirconia abutments was significantly higher than that of 25° ASC zirconia abutments. CONCLUSIONS: Within the limitations of this in vitro study the mean fracture load was significantly higher in the group with a straight channel angulation.

Asunto(s)

RESUMEN

The employment of implant-supported crowns and bridges has become a well-established and preferred approach in replacing missing teeth. A favorable implant position is mandatory to obtain good esthetic results and ideal emergence of screw access hole. Usually, unfavorably placed implants are the result of insufficient bone volume which leads to implant trajectory in the available bone. Once placed, they are restored giving a cement-retained prosthesis to avoid labial/buccal screw access holes. A graftless solution for this scenario may be using an angulated screw channel technology which corrects the prosthetic screw access hole emergence in an alternative direction which is more esthetic and acceptable. Dynamic Abutment® Solutions system is unique and exclusive and can be used as a true alternative to titanium-angulated abutments or customized Ti abutments designed through computer-aided design and computer-aided manufacturing technologies. The Dynamic Abutment® solutions system rectifies angulation issues with millimetric precision up to 30° with full freedom of movement. This case report explains a case where a two-implant supported fixed partial denture was employed in the esthetic zone using Dynamic Abutment® Solutions system with angulation rectification by a graftless procedure.

RESUMEN

BACKGROUND: Implant-supported restorations in the posterior region are subjected to various complications that could be prevented by changing either the design or the material. PURPOSE: The aim of this prospective case series study was to evaluate full-zirconia implant-supported restorations with angulated screw channel abutments in the molar region of the maxilla and mandible and their effect on hard and soft peri-implant tissues, during a 1-year follow-up period. MATERIALS AND METHODS: Thirty consecutive patients with a single missing molar, sufficient bone height, and implant site free of infection were included. Each patient was to receive a parallel-walled implant with conical connection according to a two-staged surgical protocol. After 3 months, a full-contour screw-retained zirconia restoration with angulated screw channel abutment was provided. Clinical and radiographic examinations were performed 1 and 12 months after placement of the restoration. Patients' satisfaction was scored prior to treatment and after 12 months with the restoration in function. Primary outcome measure was success of the restoration. RESULTS: All patients could be evaluated after 12 months. Success of the restorations was 100%. From loading to the 12-month follow-up, the mean marginal bone loss was 0.16 mm (SD: 0.26). Mean scores for plaque, calculus, peri-implant mucosa, bleeding, and pocket probing depth were low, depicting healthy peri-implant conditions. Patients' satisfaction was high and had improved after treatment. CONCLUSION: Full-contour zirconia implant-supported restorations with angulated screw channel abutments in the molar region have an excellent clinical performance after 1 year of function.

Asunto(s)

RESUMEN

BACKGROUND: A new implant design was launched in 2015 with internal connection allowing for placement of abutments with angulated screw channels. Such devices may eliminate the use of nonauthentic components, which may present with poor fit and jeopardize the construction. It may also eliminate the use of cemented single-crowns with the risk for excessive cement to cause marginal bone destruction. PURPOSE: To evaluate the outcome of a straight-walled implant with conical connection (NobelParallel CC), when used in the single-tooth situation of the anterior maxilla. Further, to elucidate the need for an abutment with angulated screw channel (ASC). MATERIALS AND METHODS: Patients referred for both implant surgery and prosthetics to rehabilitate missing single maxillary incisors/canines. Implants were placed according to a two-staged surgical procedure. Patients were followed up to delivery of prosthetic crowns with the purpose to extend the study up to 1-, 3-, and 5-year follow up. Registrations of implant survival, marginal bone level measurements, hard/soft tissue complications, and the incidence of ASC to avoid the use of nonauthentic components or crown cementation, were performed at the end of the study. RESULTS: A total of 47 patients were included in the current investigation. One patient deceased during the study period. In all 51 implants were inserted, of which 14 implant sites were bone augmented either prior to implant placement or in connection with the insertion procedure. Further, four remaining teeth were extracted in the region of interest during implant placement. One implant presented with infection and mobility at abutment connection and was consequently removed. Implant survival rate was 98.0%. Mean marginal bone level at crown placement was 0.41 mm (SD = 0.45 mm) and the corresponding measurements at 1 year for 22 implants revealed a marginal bone resorption of 0.41 mm (SD = 0.36 mm). Abutments with angulated screw channels were used in 42/49 sites. CONCLUSION: The NobelParallel CC implant seemed to work well together with the ASC abutment. No major complications were noted.

Asunto(s)