Implant-supported cement-screw-retained crowns combine the advantages of screw-retained and cement-retained crowns. However, the occlusal screw access hole interrupts porcelain integrity, which may ...result in porcelain cracks or fractures. There is insufficient scientific evidence to prove that screw access holes affect the fracture load of implant-supported monolithic zirconia crowns. In this study, we investigated the effects of the screw access hole and its preparation technique on the fracture load of implant-supported monolithic zirconia single crown. The crowns were designed for the maxillary right first premolar. Three techniques analysed for screw access hole preparations included computer-aided designed/computer-aided manufactured (CAD/CAM) before sintering, manually prepared after sintering, and then resintering. Our findings show that the screw access holes and preparation techniques have no significant effects on the fracture load of implant-supported monolithic zirconia single crown. On the other hand, the screw access hole preparation techniques affect failure initiation in implant-supported monolithic zirconia single crown.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The aim was to assess the peri-implant clinicoradiographic status and prostaglandin E2 (PGE2) levels in peri-implant sulcular fluid (PISF) samples collected from individuals with cement-retained and ...crew-retained implants.
In this observational study, participants with cement-retained and screw-retained implants were enrolled. A questionnaire was utilized to gather demographic information and assess the educational background of the participants. Peri-implant modified plaque and bleeding indices, probing depth, and crestal bone loss were measured. Subsequently, PISF samples were collected, and corresponding volumes were recorded. Commercial kits employing enzyme-linked immunosorbent assay were employed to quantify PGE2 levels. The sample size was determined, and group comparisons were conducted using the Student t test and the Mann-Whitney U-test. Logistic regression models were constructed to evaluate the correlation between PGE2 levels and clinicoradiographic and demographics. The predefined level of significance was established at P < .05.
Sixty-seven participants, consisting of 33 with cement-retained implants and 34 with screw-retained implants, were included in the study. The mean ages for individuals with cement and screw-retained implants were 54.2 ± 8.7 and 58.7 ± 7.4 years, respectively. The majority of participants had completed university-level education. Reportedly, 87.9% and 82.4% of individuals with cement and screw-retained implants, respectively brushed teeth twice daily. No significant differences were observed in clinicoradiographic parameters, PGE2 volume, and levels between cement-retained and screw-retained implants. There was no correlation between PGE2 levels and peri-implant clinicoradiographic parameters among individuals with either cement-retained or screw-retained implants.
Cement-retained and screw-retained implants exhibit a consistent peri-implant clinicoradiographic status, accompanied by stable levels of PGE2 in PISF provided oral hygiene maintenance regimens are stringently followed.
Purpose
Analog and digital impressions are established procedures for restoration of single‐tooth implants. In this study, single‐tooth implants were restored with definitive restorations during ...second‐stage surgery. Analog and digital workflows were compared.
Material and Methods
Eighty single‐tooth implants were examined in total. In 40 implants, an index was taken immediately after implant placement using composite resin to fabricate the final crowns (analog workflow). For the other 40 single‐tooth implants, intraoral intraoperative scans were performed (digital workflow) during primary surgery. The custom‐fabricated screw‐retained crowns were placed during second‐stage surgery. Photographs and examinations for the scores were taken at the time of the follow‐up visit, 1–4 years after placement of the crowns. The number of treatment appointments required was recorded and the modified pink esthetic score (PES) was determined. Additionally, the functional implant prosthetic score (FIPS) was measured.
Results
The mean PES was 12.15/14 for the digital workflow and 11.95/14 for the analog workflow. The most common deficit was incomplete papillae for both workflows. Three treatment appointments were required for both workflows: (1) Scan and/or impressions making and patient consent, (2) implant placement, and (3) second‐stage surgery with crown insertion. The FIPS was 9.1/10 for the digital workflow group and 9.2/10 for the analog workflow group. Common deficits presented as missing papillae as well as open approximal contacts. The FIPS was not significantly different between workflows (p = 0.679). The PES also did not show a statistically significant difference for both workflows (p = 0.654), however, the analog workflow showed better values for the papillae (p < 0.05). A significant difference was also found in the other PES values, with the digital workflow showing better results here (p < 0.05). A chronological analysis of the results of the digital technique showed that the cases treated last had significantly better values than the cases treated first.
Conclusions
According to the results of this study, both workflows allowed placement of the definitive crowns on single‐tooth implants during second‐stage surgery. Both workflows were found to be equivalent in terms of esthetic results in this study, although the digital workflow demonstrated a learning curve.
Background
Screw‐retained implant crowns are considered more biologically compatible than cemented crowns due to the absence of excess cement. However, traditional screw‐retained implant crowns are ...not viable when the access hole of the screw channel would need to be located in an esthetic area, which would compromise the esthetic outcome of the treatment.
Purpose
To evaluate the clinical, radiographic, and immunological outcomes of angulated screw‐retained and cemented single‐implant crowns in the esthetic region.
Materials and methods
The study was a single‐center, open‐label, randomized controlled clinical trial. Eligible patients were randomly placed in two groups: angulated screw‐retained group (AG) and cemented group (CG). Implant survival rate, bleeding on probing rate (BOP%), probing depth (PD), modified plaque index (mPI), marginal bone loss (MBL), concentrations of pro‐inflammatory cytokines (TNF‐α, IL‐6) in peri‐implant crevicular fluid (PICF), mechanical complications, and pink esthetic score/white esthetic score (PES/WES) were evaluated.
Results
Fifty‐six patients (AG: 29, CG: 27) attended the 1‐year examination. The drop‐out rate was 6.67%. No implant failure was found in both groups during the observation period. BOP% was significantly lower in the AG than that in the CG (mean, 21.84% ± 19.97% vs. 37.04% ± 26.28%, p = 0.018). The concentration of TNF‐α in PICF was significantly higher in the AG than that in the CG (median, 13.54 vs. 4.62, p = 0.019). No significant difference of PD, mPI, MBL, IL‐6, or mechanical complication rates was found between the two groups. Mean scores for PES/WES were 21.71 and 21.64 in the AG and CG, respectively.
Conclusion
Based on the present results, both treatment options showed acceptable clinical outcomes in the short term. Angulated screw‐retained crowns might benefit the peri‐implant soft tissue. However, studies with long‐term follow‐up are needed to confirm whether the higher concentration of TNF‐α will compromise the long‐term outcomes of treatment.
Objectives
The objective of the present randomized clinical trial was to test whether or not the use of screw‐retained all ceramic implant‐borne reconstructions results in clinical, technical, and ...biologic outcomes similar to those obtained with cemented all ceramic reconstructions. The hypothesis was that there is no difference in clinical, technical, and biological parameters between the two types of retention.
Materials and Methods
Forty‐four patients randomly received 20 cemented reconstruction (CR) and 24 screw‐retained (SR) all ceramic single crowns on two‐piece dental implants with nonmatching implant‐abutment junctions. All patients were recalled after crown insertion, at 6 months, 1 year, as well as at 3 years. At these visits, biological and radiographic evaluations were performed. Technical outcomes were assessed using modified USPHS (United States Public Health Service) criteria. Data were statistically analyzed with Wilcoxon‐Mann‐Whitney, Wilcoxon and Fisher exact tests.
Results
During 3 years of follow‐up, eight patients (18.2%) lost the reconstruction due to technical (6 patients, 13.6%, 2 CR and 4 SR group) or biological complications (2 patients, 4.5%, only CR group). Thirty‐two subjects with 18 SR and 14 CR reconstructions attended the FU‐3Y, whereas four patients (9.1%, 2 SR, 2 CR) were not available (drop‐outs). Biological, technical, and radiographic outcomes did not differ significantly between the groups (P > 0.05). One implant (2.3%) was lost in the CR group. One more cemented crown (2.3%) had to be removed because of peri‐implant disease. Six patients (13.6%) lost the reconstructions due to a fracture of the zirconia abutment (4 SR, 2 CR). The mean marginal bone level at 3 years was −0.4 mm (−0.5; −0.3) in group SR and − 0.4 mm (−0.6; −0.3) group CR (P = 0.864).
Conclusions
At 3 years, CR and SR exhibited similar survival technical, biological and radiographic outcomes. The rate of technical complications was high in both groups.
Objective
To assess the prostheses and implants survival rate and peri‐implantitis rate in edentulous patients treated with full‐arch screw‐retained implant‐supported fixed dental prostheses ...(FSIFDPs) and full‐arch telescopic‐retained implant‐supported fixed dental prostheses (FTIFDPs) over an observation period of at least 5 years.
Materials and methods
From 2004 to 2012, 696 implants were inserted into 78 patients with 102 prostheses. The FSIFDP group comprised 31 patients (37 prostheses, 232 implants), whereas the FTIFDP group comprised 47 patients (65 prostheses, 464 implants). Prosthesis and implant estimated cumulative survival rates (ECSR) and estimated cumulative peri‐implantitis rates (ECPR) were assessed. The follow‐up period was 5–12 years. Kaplan–Meier survival curves with the log‐rank test were used to evaluate outcomes.
Results
The 12‐year prosthesis ECSR was 96.8% (95% CI: 79.2–99.5, 36/37 prostheses) in the FSIFDP group and 96.4% (95% CI: 86.3–99.1, 63/65 prostheses) in the FTIFDP group, whereas the 12‐year implant ECSR was 99.5% (95% CI: 96.4–99.9, 231/232 implants) in the FSIFDP group and 98.7% (95% CI: 96.9–99.5, 459/464 implants) in the FTIFDP group. The 12‐year ECPR at the prosthesis level was 12.8% (95% CI: 12.7–47.6, 4/37 prostheses) in the FSIFDP group and 12.8% (95% CI: 11.4–24.1, 6/65 prostheses) in the FTIFDP group. The 12‐year ECPR at the implant level was 4.4% (95% CI: 4.3–23.0, 6/232 implants) in the FSIFDP group and 2.2% (95% CI: 2.0–12.3, 7/464 implants) in the FTIFDP group.
Conclusion
FTIFDPs have clinical results comparable to those of FSIFDPs. Therefore, FTIFDPs can be useful.
Purpose
The purpose of this randomized controlled clinical trial was to investigate the prosthetic outcomes of posterior implant‐supported single crowns (SCs) with a modified monolithic zirconia or ...metal‐ceramic design at 1 year of loading.
Materials and Methods
Forty participants with 73 dental implants in need of at least 1 maxillary or mandibular posterior implant‐supported SC were consecutively selected for this study. The included participants were randomly divided into modified monolithic zirconia (MMZ) and metal‐ceramic (MC) groups. The implant‐supported SCs were examined after 1 year for survival and technical complications. Descriptive statistics were used to illustrate the data, and the association associated risks of complications were estimated using the logistic regression model with Firth's approach for rare outcome (α = 0.05).
Results
During the observation period, 2 participants in the MC group were lost to follow‐up. A total of 38 participants with 70 posterior implant‐supported SCs (36 and 34 SCs in the MMZ and MC groups respectively) completed the 1‐year follow‐up examination. One implant failed in the MMZ group. The 1‐year survival rates for implants and crowns were both 97.2% in the MMZ group. The survival rates for implants and crowns were both 100% in the MC group. One screw loosening event was observed in one screw‐retained SC in the MMZ group; however, 8 complication events occurred in 7 SCs in the MC group. Therefore, the complication‐free rates were 97.1% and 79.4% in the MMZ and MC SCs respectively. The most common complication in the MC group was screw loosening (14.7%), followed by loss of retention (5.9%), and ceramic fracture (2.9%). Significantly more technical complications were observed in the MC SCs than MMZ SCs (p = 0.0432).
Conclusion
The modified monolithic zirconia design applied to the posterior implant‐supported SCs had a significantly lower technical complication rate than did the metal‐ceramic one.
Purpose
To evaluate the fatigue survival, fracture loads and failure modes of monolithic lithium disilicate screw‐retained crowns, attached to titanium insert, and cement‐retained crowns.
Materials ...and Methods
Internal tapered connection implants, embedded in acrylic resin at 30° inclination, were restored with lithium disilicate restorations, simulating a maxillary premolar (n = 20), with different designs: screw‐retained titanium base abutment‐crowns, and cement‐retained crowns. The specimens were submitted to cyclic mechanical loading (1.2 × 106 cycles with a load of 0‐250 N at 2 Hz). Surviving specimens were subjected to single load to fracture in a universal testing machine and failure modes were determined with the aid of an optical microscope. Maximum load values were analyzed statistically using the t‐test and differences in failure modes were analyzed using the chi‐squared test (α = 0.05).
Results
All specimens survived the cyclic mechanical loading. Fracture load was significantly higher for screw‐retained crowns (821.69 ±196.71 N) than the cement‐retained crowns (577.03 ± 137.75 N) (p = 0.005). Ceramic failure was the predominant mode, with no statistical difference between groups.
Conclusions
Screw‐retained and cement‐retained lithium disilicate crowns survived the cyclic mechanical loading. The use of titanium inserts to support a monolithic restoration enhances the fracture strength of the crown/abutment system.
Single-tooth implant restorations, whether screw-retained or cement-retained, are essential for prosthodontic rehabilitation despite having low design flexibility, cosmetic appeal, and high 5-year ...survival rates.
A study involving 14 patients with missing mandibular first molars used 28 implants and cement-retained and screw-retained prostheses. Patients had a single edentulous gap, adequate dental hygiene, and sufficient bone volume at the implant site. The study adhered to the Helsinki Declaration, followed WHO 2007 safety guidelines, and evaluated soft tissue, bone height, and bone loss. Data analysis included the Student's
-test and Mann-Whitney
-test.
In patients between the ages of 17 and 46, single-implant restorations were compared with cement- and screw-retained at 6 months. Abutment screw loosening and peri-implant soft-tissue traits did not differ significantly from one another.
The study compared screw- and cement-retained implant restorations in 28 single-tooth implant-supported prostheses over a 6-month functional loading period, finding no significant improvement in either approach.
Screw-retained implant restorations have an advantage of predictable retention, retrievability, and lack of potentially retained subgingival cement. However, a few disadvantages exist such as need ...for precise placement of the implant for optimal and esthetic location of the screw access hole and obtaining passive fit. Malo bridge with customization of abutment can establish a precise patient's gingival architecture. It is the most esthetically advanced form of fixed prosthodontic rehabilitation for complete and partially edentulous patients. This prosthesis is combined with three-dimensional (3D)-printed computer-aided design and computer-aided manufacturing technology to gain the precise fit and added esthetics. It also has advantages such as elimination of screw access openings, makes it possible to remove and repair the fractured porcelain of the individual crown without removing the whole structure, excellent precision, avoids casting errors, light weight, reduced complexity of laboratory procedures, high definition of morphology, and time-consuming. This case report presents replacement of partially edentulous maxilla using 3D-printed Malo bridge.
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