Comparing short implants to standard dental implants: a systematic review and meta-analysis of randomized controlled trials with extended follow-up.

PURPOSE: To compare the difference of marginal level changes (MBL), implant failure (IF), biological and prosthetic complications (BC and PC), and prosthetic failure (PF) of short implants (SH) and standard implants (ST). MATERIALS AND METHODS: Electronic searches (PubMed, Web of Science, EMBASE, Scopus, Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov) and manual searches were performed to identify all randomized controlled trials (RCTs) evaluating SH to ST. Applying Stata, a meta-analysis was conducted on the weighted mean difference (WMD) and standardized mean difference (SMD) of MBL and the risk difference (RD) of the secondary outcome. RESULTS: Twenty-four articles were involved in the present study. There were statistically significant differences in MBLs, preferring short implants in the maxilla (WMD: -0.147 (CI: -0.224, -0.070), I2: 76.6%; SMD: -0.757 (CI: -1.226, -0.289), I2: 89.2%) and in the mandible (WMD: -0.377 (CI: -0.656, -0.098), I2: 85.8%; SMD: -0.811 (CI: -1.418, -0.204), I2: 78.8%). There were no significant differences in IF (RD: 0.011 (-0.002, 0.023), I2: 0.0%), PF (RD:0.003 (-0.007, 0.014), I2: 0.0%), and PC (RD:0.001 (-0.008, 0.010), I2: 0.0%). There were significantly higher biological complications (RD: -0.071 (-0.106, -0.036), I2: 0.82.9%) for ST compared to SH in both jaws up to a 10-year follow-up. CONCLUSION: SH and ST had comparable overall outcomes, but short implants had less marginal bone loss and lower biological complications. However, more research is needed to confirm these findings.

Dimensional changes of peri-implant tissue following immediate flapless implant placement and provisionalization with or without xenograft in the anterior maxilla: a study protocol for a randomized controlled trial.

BACKGROUND: Dental implant therapy requires the preservation of peri-implant tissue in the cosmetic zone. Various surgical procedures have been presented, including ridge preservation, flapless method, and quick provisionalization. The goal of this research was to assess the buccal bone dimensional changes following immediate flapless implant implantation in the front maxilla, with or without xenografting. METHOD AND DESIGN: Thirty patients who meet the inclusion criteria and have maxillary teeth (numbers 14 to 24) are candidates for the immediate implant with immediate provisionalization. Participants will be assigned randomly to one of two groups: (1) an immediate implant with xenograft and (2) an immediate implant without bone grafting. For 3 months, the temporary prosthesis will be installed shortly before the final restoration. Following temporary prosthesis insertion and 6 months after surgery, a CBCT radiograph will be used to examine bone tissue. Soft tissue will be assessed at three points: baseline, 3 months, and 6 months following implant therapy. Patients' satisfaction, implant failure, prosthesis failure, and complications will be assessed as secondary outcomes after 6 months. DISCUSSION: The outcomes of this randomized clinical research will show if buccal bone augmentation with xenograft reduces vertical bone and gingiva recession. The findings and patient-reported outcomes will aid in the selection of therapy alternatives for implant treatment patients. TRIAL REGISTRATION: Iranian Registry of Clinical Trials IRCT20211119053106N1. Registered on 6 December 2021 and Open Science Framework (OSF) on May 20, 2022. Registration DOI https://doi.org/10.17605/OSF.IO/VUGFQ .

Immediate vs Delayed Restorations of Immediately Placed Single Implants in the Anterior Maxilla: A Nonrandomized Clinical Study.

PURPOSE: This study was conducted to compare the radiographic, esthetic, and patient-reported outcome measures (PROMs) between immediate and delayed restorations of immediately placed single implants in the maxillary esthetic zone. MATERIALS AND METHODS: Forty patients with immediate single dental implants in the anterior maxilla were included in this study. Afterward, they were allocated either for immediate restoration with a provisional restoration (IR: 20 patients) or for a delayed restoration (DR: 20 patients). The evaluations were performed after 1 year of follow-up. RESULTS: No implant and prosthetic failures were observed during the 1-year follow-up. Two minor complications were found in two IR patients; however, no complication was reported in the DR group during the 1 year. Nevertheless, this difference was not statistically significant (P > .05). After 1 year, the mean marginal bone level changes (MBL) were 0.47 ± 0.29 mm and 0.54 ± 0.21 mm for IR and DR, respectively. There was no statistically significant difference between the two groups in terms of MBL (P = .3). Notably, the mean total pink esthetic score (PES) and white esthetic score (WES) after 1 year of follow-up were 11.2 ± 1.1 (PES) and 8 ± 1.02 (WES) for the immediate restoration, and 10.2 ± 0.97 (PES) and 7.65 ± 1.20 (WES) for the delayed restoration. Also, no statistically significant difference was found between IR and DR in terms of esthetic scores (P > .05). The patient satisfaction of these two groups had no statistically significant difference, except for the esthetic factor (P = .04). CONCLUSION: The immediate restoration and preferred esthetic satisfaction had similar outcomes compared with the delayed restoration.

Comparing short dental implant and standard dental implant in terms of marginal bone level changes: A systematic review and meta-analysis of randomized controlled trials.

PURPOSE: To compare short implants (SH; 4-8 mm) to standard implants (ST; longer than 8 mm) in edentulous jaws, evaluating pri-implant marginal bone levels (MBLs) changes, implant failures (IFs), complications, and prosthesis failures (PFs). MATERIALS AND METHODS: Electronic searches were conducted through the PubMed, Web of Science, EMBASE, Scopus, the Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov to locate all randomized controlled trials (RCTs) comparing SH to ST. Meta-analysis procedures were performed on the weighted mean difference (WMD) and standardized mean difference (SMD) of MBLs using Stata. RESULTS: Twenty-three articles were included in this review. The WMD of MBLs when comparing SH to ST in both jaws up to 1-year follow-up was statistically significant preferring SH (WMD: -0.09 [CI: -0.12, -0.06], I2 : 67.0%). The efficacy of SH vs ST on SMD of MBLs was moderate (SMD: -0.43 [CI: -0.57, -0.28], I2 : 55.7%). There were no significant differences in IF (RR: 0.75 [0.44,1.27]) and PF (RR: 0.58 (0.22,1.581), and significantly higher biological complications (RR: 0.25 [0.15, 0.40]) for SH was observed compared to the ST in both jaws up to 1-year follow-up. CONCLUSIONS: SH and ST implants showed the comparable outcomes except biological complication preferring SH. Future systematic review and meta-analysis with longer and larger RCTs are required to confirm the present outcomes.

Comparing 4-mm dental implants to longer implants placed in augmented bones in the atrophic posterior mandibles: One-year results of a randomized controlled trial.

BACKGROUND: Short implants have been proposed as an alternative for the rehabilitation of atrophic edentulous areas. PURPOSE: To evaluate the efficacy of 4-mm implants vs longer implants in the atrophic posterior mandibles. MATERIALS AND METHODS: Eleven patients with bilateral atrophic mandibles were rehabilitated with two to four 4-mm implants and 10 or 8-mm long implants in augmented bone using Guided Bone Regeneration procedure. One side of the mandibles was randomly allocated to vertical augmentation with mixed autogenous bone and allograft. Implants were placed in both sides of the mandible after 6 months, and loaded after another 2 months. Subsequently, implant and prosthesis failures, marginal bone levels changes, and any complication were evaluated after 1-year follow-up. RESULTS: In this study, one patient dropped out and no failures occurred. However, 4-mm implants loss of 0.30 ± 0.34 mm peri-implant marginal bone and long implants loss of 0.47 ± 0.54 mm marginal bone were observed after 1-year of follow-up. The difference between the two groups was not statistically significant (difference = -0.16 ± 0.68 mm; P = 0.46). Eight complications occurred in five augmented sites of the patients, and no complication was found to occur in the short implants sites. CONCLUSIONS: One-year after loading, 4-mm implants had similar outcomes as long implants in augmented bone. Therefore, short implants might be a feasible treatment in atrophic mandibles.

Comparison of Short and Standard Implants in the Posterior Mandible: A 3D Analysis Using Finite Element Method.

OBJECTIVES: This study aimed to analyze functional stresses around short and long implant-supported prostheses with different crown heights. MATERIALS AND METHODS: Four three-dimensional (3D) models were designed with SolidWorks 2015. In models 1 (control) and 2, three dental implants (second premolar 4.1×8 mm, molars: 4.8×8 mm) were placed. In models 3 and 4, three dental implants (second premolar 4.1×4 mm, molars: 4.8×4) were placed. Residual bone height was 10 mm in groups 1 and 2 (grafted bone) models and 6 mm in groups 3 and 4. The crown heights were modeled at 11.5 mm for groups 1 to 3, and 15 mm for group 4. The applied oblique force was 220 N to simulate chewing movements. The maximum von Mises and principal stresses on the implants and the supporting tissues were compared using the 3D finite element method. RESULTS: In all models, the highest stress value was seen within the most coronal part of bone (crestal bone), which was cortical or grafted bone. The highest stress values in the bone supporting the implant neck were seen in the premolar region of each model, especially in model 4 (291.16 MPa). The lowest stress values were demonstrated in the molar region of model 3 (48.066 MPa). The model 2 implants showed the highest von Mises stress concentrated at their neck (424.44 MPa). CONCLUSIONS: In atrophic posterior mandible with increased crown height space, short implants with wider diameter seem to be a more feasible approach compared to grafting methods.

Comparing Short Dental Implants to Standard Dental Implants: Protocol for a Systematic Review.

BACKGROUND: Short dental implants have been proposed as a simpler, cheaper, and faster alternative for the rehabilitation of atrophic edentulous areas to avoid the disadvantages of surgical techniques for increasing bone volume. OBJECTIVE: This review will compare short implants (4 to 8 mm) to standard implants (larger than 8 mm) in edentulous jaws, evaluating on the basis of marginal bone loss (MBL), survival rate, complications, and prosthesis failure. METHODS: We will electronically search for randomized controlled trials comparing short dental implants to standard dental implants in the following databases: PubMed, Web of Science, EMBASE, Scopus, the Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov with English language restrictions. We will manually search the reference lists of relevant reviews and the included articles in this review. The following journals will also be searched: European Journal of Oral Implantology, Clinical Oral Implants Research, and Clinical Implant Dentistry and Related Research. Two reviewers will independently perform the study selection, data extraction and quality assessment (using the Cochrane Collaboration tool) of included studies. All meta-analysis procedures including appropriate effect size combination, sub-group analysis, meta-regression, assessing publication or reporting bias will be performed using Stata (Statacorp, TEXAS) version 12.1. RESULTS: Short implant effectiveness will be assessed using the mean difference of MBL in terms of weighted mean difference (WMD) and standardized mean difference (SMD) using Cohen's method. The combined effect size measures in addition to the related 95% confidence intervals will be estimated by a fixed effect model. The heterogeneity of the related effect size will be assessed using a Q Cochrane test and I2 measure. The MBL will be presented by a standardized mean difference with a 95% confidence interval. The survival rate of implants, prostheses failures, and complications will be reported using a risk ratio at 95% confidence interval (P<.05). CONCLUSIONS: The present protocol illustrates an appropriate method to perform the systematic review and ensures transparency for the completed review. The results will be published in a peer-reviewed journal and social networks. In addition, an ethics approval is not considered necessary. TRIAL REGISTRATION: PROSPERO registration number: CRD42016048363; https://www.crd.york.ac.uk/PROSPERO/ display_record.asp?ID=CRD42016048363 (Archived by WebCite at http://www.webcitation.org/6wZ7Fntry).

IPS-Empress II inlay-retained fixed partial denture reinforced with zirconia bar: three-dimensional finite element and in-vitro studies.

OBJECTIVE: This study evaluated von Mises stress distribution, flexural strength and interface micrographs of IPS-Empress II (IPS) inlay-retained fixed partial dentures (IRFPD) reinforced with Zirconia bars (Zb). MATERIALS AND METHODS: In the Finite element analysis, six three-dimensional models of IRFPD were designed using Solid Works 2006. Five models were reinforced with different Zb and a model without Zb was considered as a control. The bridges were loaded by 200 and 500 N forces at the middle of the pontic on the occlusal surface. Subsequently, von Mises stress and displacement of the models were evaluated along a defined path. In the experimental part, 21 bar shape specimens were fabricated from lithium disilicate and zirconia ceramic in three different designs. The zirconia-IPS interfaces and the fractured surfaces of flexural test were observed using SEM. RESULTS: In the connector area, von Mises stress and displacement of the models with Zb under a load of 500 N were decreased compared to the model without the Zb; however, this difference was not considerable at a load of 200 N. In the mesial connector, Von Mises stress and displacement was decreased from 12.5 Mpa for the control model tested at 500 N to 7.0 Mpa for the model with Zb and from 0.0050-0.0041 mm, respectively. SEM analyses showed that, before fracture, interfacial gaps were not observed along the interfaces, but initiated cracks propagated along the interfaces after flexural loading. CONCLUSION: IPS IRFPD reinforced by Zb can tolerate higher stresses while still functioning effectively and the interfaces may have desirable adaption.

Comparison of the microshear bond strength of feldspathic porcelain to enamel with three luting resins.

PURPOSE: The purpose of this study was to compare microshear bond strength of three different luting resins using a new microshear method closely simulating clinical condition. METHODS: Thirty 1-mm-thick slices of intact human first molars and thirty 0.8-mm-diameter feldspathic porcelain rods were etched by 37% phosphoric acid for enamels and 9.5% hydrofluoric acid for porcelains. Adhesive (Margin bond) was applied on both silaned porcelain and enamel surfaces. Three luting agents were used as follows: (1) dual polymerized cement (DP) (Variolink II refill), (2) light polymerized cement (LP) (Variolink II base), and (3) flow composite (FC) (Tetrick flow). Porcelain rods were attached to flat enamel surfaces followed by cementation. The specimens were thermal cycled for 500 cycles between 5 and 55°C, and microshear test was then performed with wire and loop method using Dillon Quantrol. Modes of failure were identified by stereomicroscope, and one sample of each group was observed with SEM. finally collected data were statistically analyzed using one-way ANOVA (P<.05). RESULTS: The mean microshear bond strengths were 21.48 (DP), 23.92 (LP) and 24.57 (FC) in MPa units. Most cohesive failures occurred in groups LP and FC, whereas most adhesive failures were observed in group DP. CONCLUSION: Bond strength of feldspathic porcelain to enamel with studied luting resins were not significantly different among the groups based on current method (P<.05).