Effect of dental implant therapy on the preservation of orofacial tissues: A systematic review and meta-analysis.

OBJECTIVE: Fundamentally, this review addresses the following question: In partially or fully edentulous patients, do implant-supported dental prostheses preserve orofacial tissues when compared to conventional prostheses or no therapy? MATERIALS AND METHODS: This study was conducted according to the 2020 PRISMA guidelines for systematic reviews. Electronic searches were conducted at PubMed and Embase databases followed by manual search. Clinical studies comparing the effect of implant-supported prostheses with conventional rehabilitation or no treatment on alveolar bone resorption, remaining teeth, and jaw muscle thickness were considered for inclusion. A qualitative synthesis was conducted with all included studies, and data from selected studies were pooled quantitatively to perform a meta-analysis. RESULTS: A total of 14 studies were selected for analysis. Six studies reported on the effect of implant therapy on alveolar bone resorption (n = 453), six on the remaining teeth (n = 1014), while four studies evaluated masseter muscle thickness (n = 158). The results of the meta-analyses assessing alveolar bone resorption in the posterior mandible and in the anterior area of the maxilla, both fixed and random effects models, yielded no benefit of rehabilitation with implant-supported prostheses when compared to conventional prostheses. For masseter bone thickness, however, a significant benefit for implant-supported prosthesis was observed. CONCLUSIONS: This systematic review and meta-analysis were unable to unequivocally answer the focus question. There are some indicators of the benefit of implant-supported prostheses over conventional prostheses or no therapy in preserving orofacial tissues, particularly for masseter muscle thickness. However, the evidence is still insufficient to confirm such perception.

Complete digital workflow for prosthesis prototype fabrication with double digital scanning: A retrospective study with 45 edentulous jaws.

PURPOSE: To assess the accuracy of fit of complete-arch printed prosthesis prototypes generated with a digital workflow protocol for completely edentulous jaws. MATERIALS AND METHODS: Forty-five edentulous jaws (35 patients) underwent intraoral complete-arch digital scans with the double digital scanning (DDS) technique and the generated standard tessellation language (STL) files were superimposed and imported into computer-aided design software. After STL merging, each master STL file was used for printing a prosthesis prototype. The primary outcome was the accuracy of fit assessment of the printed prototypes on verified master stone casts. Two experienced clinicians tested the accuracy of fit with radiographs and screw-resistance tests. Secondary outcomes were the effect of the scan body shape and implant number on the accuracy of fit. RESULTS: Out of the 45 DDS-generated prosthesis prototypes, 39 presented with accurate fit on verified master stone casts, yielding an 86.70% accuracy of fit. Cylindrical scan bodies led to 100% accuracy of fit (25/25), whereas polygonal scan bodies presented with 70% accuracy of fit (14/20). Four implant-supported prostheses yielded 100% accuracy of fit (12/12), compared with 25/29 (86.30%) accuracy of fit for the six-implant-supported ones. Fisher's exact test was used to assess the effect of different scan body shapes (p = 0.005) and implant number on accuracy of fit. Chi-squared test was used to assess the association between the number of implants per arch and the accuracy of fit (p = 0.039). CONCLUSIONS: Thirty-nine out of 45 complete-arch prosthesis prototypes generated with a completely digital workflow presented with clinically acceptable fit. The effect of the scan body design and implant number was statistically significant, favoring cylindrical scan bodies and four-implant-supported prostheses.

Digital vs Conventional Full-Arch Implant Impressions: A Retrospective Analysis of 36 Edentulous Jaws.

PURPOSE: There is a paucity of comparative clinical studies assessing the accuracy of full-arch digital scans versus conventional implant impressions. The aim of this retrospective study was to compare the three-dimensional (3D) deviations between full-arch digital scans and conventional implant impressions for edentulous maxillae and mandibles. MATERIALS AND METHODS: Twenty-seven patients (36 edentulous jaws) were treated with one-piece, screw-retained implant-supported fixed complete dental prostheses (IFCDPs). Twenty-one jaws were maxillary, and 15 were mandibular. Full-arch conventional impressions and intraoral digital scans with scan bodies and an intraoral scanner had been taken during the impression phase. Following verification of the conventional stone casts, the casts were digitized. The generated standard tessellation language (STL) files from both impression techniques were merged and analyzed with reverse engineering software. The primary aim was to evaluate the accuracy between conventional and digital full-arch scans, while the effect of the edentulous jaw in 3D accuracy was the secondary aim. RESULTS: The cumulative 3D (mean ± SD) deviations between virtual casts from intraoral full-arch digital scans and digitized stone casts generated from conventional implant impressions were found to be 88 ±24 µm. In the maxillary group, the mean ± SD 3D deviation was 85 ±25 µm, compared to 92 ±23 µm for the mandibular group (p = 0.444). CONCLUSION: The 3D implant deviations found between the full-arch digital and conventional impressions lie within the clinically acceptable threshold. No statistically significant difference was identified between maxillary and mandibular jaws in terms of 3D deviations.

An Esthetic Evaluation of Different Abutment Materials in the Anterior Maxilla: A Randomized Controlled Clinical Trial Using a Crossover Design.

PURPOSE: To assess the effect of implant abutment material and soft tissue thickness on the peri-implant soft tissue color using spectrophotometry and to evaluate gingival esthetics and patient satisfaction with three different abutments. MATERIALS AND METHODS: Twenty-five patients with a missing maxillary tooth in the esthetic area received an endosseous implant using a two-stage protocol. Gray titanium, pink anodized titanium, and hybrid zirconia custom abutments were fabricated for each participant and inserted for one week with a cross-over design in a randomized manner. Color measurements were made using a spectrophotometer comparing midfacial peri-implant soft tissue and marginal gingiva of the contralateral tooth. CIE Lab color scale was used following the formula: ΔE = [(∆L)2 + (∆a)2 + (∆b)2 ]½ . PES scores were recorded, and patient satisfaction questionnaires were completed at each abutment change visit and at 1-year follow-up. Statistical analysis was performed using Friedman's test and the Wilcoxon signed-rank test with Bonferroni correction as well as the Mann-Whitney U test (α = 0.05). RESULTS: Abutment material type significantly affected the ΔΕ values of the peri-implant mucosa when compared to the contralateral teeth. At baseline, the highest ΔΕ means ± standard deviation (SD) values were obtained with gray titanium (11.25 ± 2.98), followed by pink anodized titanium (9.90 ± 2.51), and zirconia abutments (6.46 ± 1.43). Differences were statistically significant irrespective of soft tissue thickness. The highest PES values were obtained with zirconia abutments (10.88 ± 0.88), followed by pink anodized titanium (10.12 ± 1.13) and the lowest with gray titanium (9.68 ± 1.41). PES differences were significant only for the thin soft tissue group. Regarding patient satisfaction, VAS scores for the pink anodized and zirconia hybrid abutment groups were higher than the gray titanium group for each question. CONCLUSION: The color difference between soft tissues around teeth and implants was significant in all groups regardless of tissue thickness. The hybrid zirconia abutments resulted in the least color difference, followed by pink anodized and gray titanium. Significantly different PES values were recorded only for the thin tissue group. There was no significant difference in patient satisfaction between zirconia and pink anodized abutments at the 1-year follow up. Pink anodized abutments represent a good esthetic alternative to zirconia hybrid abutments especially in mechanically challenging situations.

Effect of time in function on the predictability of short dental implants (≤6 mm): A meta-analysis.

PURPOSE: To analyse randomised controlled clinical trials (RCTs) and prospective cohort studies reporting on the survival and failure rates of functionally loaded short implants (SI) based on the actual length of time in function. MATERIALS AND METHODS: This meta-analysis was conducted according to PRISMA guidelines for systematic reviews. Electronic and manual searches were conducted to identify RCTs and prospective cohort studies reporting survival and complication rates of short dental implants (≤6 mm) based on the time in function. Secondary outcomes included the location (maxilla or mandible), type of restoration (single crown [SC] versus fixed dental prosthesis [FDP]) and marginal bone loss (MBL). RESULTS: A total of 20 studies (11 RCTs and 9 prospective) fulfilled the inclusion criteria and featured a total of 1238 SI placed in 747 patients. The overall (early and late) mean percentage of short implant failure was 4%. SI with up to 1-year follow-up presented failure rate of 2%, while SI followed up for >3 years showed a failure rate of 10%. SI restored with SC presented a late failure rate of 4% while SI restored with FPD 2%. The late failure rate did not differ in terms of location (maxilla or mandible) both with 3%. CONCLUSION: Short implants in function for more than 3 years presented higher failure rates compared to SI in function for <3 years. Splinting crowns supported by SIs in the posterior area should be considered. However, SI is a valid option for selected cases given their relatively high long-term survival rates.

Digital vs Conventional Implant Impressions: A Systematic Review and Meta-Analysis.

PURPOSE: To systematically review in vitro and clinical studies comparing quantitatively the 3D accuracy (global implant deviations) of digital vs conventional implant impressions for partially and completely edentulous patients. MATERIALS AND METHODS: Electronic and manual searches were conducted to identify in vitro and clinical studies, reporting on the 3D accuracy between digital and conventional implant impressions. Secondary outcomes were the effect of implant angulation, type of conventional impression technique, and type of intraoral scanner on the accuracy of implant impressions. RESULTS: The inclusion criteria were met by 9 in vitro studies and 1 clinical study reporting on completely edentulous impressions, while 6 in vitro and 2 clinical studies reported on partially edentulous impressions. Quantitative meta-analysis was performed for 5 completely edentulous and 6 partially edentulous studies. The studies exhibited high values for heterogeneity. A random effects model was conducted to estimate the effect size. Based on 5 in vitro studies on completely edentulous impressions, the mean 3D implant deviation between conventional and digital impressions was 8.20 µm (95% CI: -53.56, 37.15) and the digital impressions had nominally less deviation (p = 0.72). Based on 1 clinical and 5 in vitro studies on partially edentulous impressions, the mean 3D implant deviation between conventional and digital impressions was 52.31 µm (95% CI: 6.30, 98.33) and the conventional impressions had nominally less deviation (p = 0.03). Five in vitro and 2 clinical studies were not included in the quantitative analysis due to heterogeneity in the methodology. Implant angulation affected the accuracy in favor of the partially edentulous conventional impressions whereas the effect of different scanners was not statistically significant on the completely edentulous impressions (p = 0.82). CONCLUSIONS: Digital scans appear to have comparable 3D accuracy with conventional implant impressions based mainly on in vitro studies. However, clinical trials are recommended to investigate the clinical accuracy of digital scans and digitally fabricated interim or prototype prostheses, before digital implant scans can be recommended for routine clinical use.

Survival rates of short dental implants (≤6 mm) compared with implants longer than 6 mm in posterior jaw areas: A meta-analysis.

PURPOSE: To systematically review randomized controlled clinical trials (RCTs) reporting on the long-term survival and failure rates, as well as the complications of short implants (≤6 mm) versus longer implants (>6 mm) in posterior jaw areas. MATERIALS AND METHODS: Electronic and manual searches were conducted to identify studies, specifically RCTs, reporting on short dental implants (≤6 mm) and their survival and complication rates compared with implants longer than 6 mm. Secondary outcomes analyzed were marginal bone loss and prosthesis survival rates. RESULTS: Ten RCTs fulfilled the inclusion criteria and featured a total of 637 short (≤6 mm) implants placed in 392 patients, while 653 standard implants (>6 mm) were inserted in 383 patients. The short implant survival rate ranged from 86.7% to 100%, whereas standard implant survival rate ranged from 95% to 100% with a follow-up from 1 to 5 years. The risk ratio (RR) for short implant failure compared to standard implants was 1.29 (95% CI: 0.67, 2.50, p = 0.45), demonstrating that overall, short implants presented higher risk of failure compared to longer implants. The heterogeneity test did not reach statistical significance (p = 0.67), suggesting low between-study heterogeneity. The prosthesis survival rates from the short implant groups ranged from 90% to 100% and from 95% to 100% for longer implant groups, respectively. CONCLUSION: Short implants (≤6 mm) were found to have higher variability and lower predictability in survival rates compared to longer implants (>6 mm) after periods of 1-5 years in function. The mean survival rate was 96% (range: 86.7%-100%) for short implants, and 98% (range 95%-100%) for longer implants. Based on the quantity and quality of the evidence provided by 10 RCTs, short implants with ≤6 mm length should be carefully selected because they may present a greater risk for failure compared to implants longer than 6 mm.

Group 1 ITI Consensus Report: The influence of implant length and design and medications on clinical and patient-reported outcomes.

OBJECTIVES: The aim of Working Group 1 was to address the influence of different local (implant length, diameter, and design) and systemic (medications) factors on clinical, radiographic, and patient-reported outcomes in implant dentistry. Focused questions on (a) short posterior dental implants (≤6 mm), (b) narrow diameter implants, (c) implant design (tapered compared to a non-tapered implant design), and (d) medication-related dental implant failures were addressed. MATERIALS AND METHODS: Four systematic reviews were prepared in advance of the Consensus Conference and were discussed among the participants of Group 1. Consensus statements, clinical recommendations, and recommendations for future research were based on structured group discussions until consensus was reached among the entire expert Group 1. The statements were then presented and accepted following further discussion and modifications as required by the plenary. RESULTS: Short implants (≤6 mm) revealed a survival rate ranging from 86.7% to 100%, whereas standard implant survival rate ranged from 95% to 100% with a follow-up from 1 to 5 years. Short implants demonstrated a higher variability and a higher Risk Ratio [RR: 1.24 (95% CI: 0.63, 2.44, p = 0.54)] for failure compared to standard implants. Narrow diameter implants (NDI) have been classified into three categories: Category 1: Implants with a diameter of <2.5 mm ("Mini-implants"); Category 2: Implants with a diameter of 2.5 mm to <3.3 mm; Category 3: Implants with a diameter of 3.3 mm to 3.5 mm. Mean survival rates were 94.7 ± 5%, 97.3 ± 5% and 97.7 ± 2.3% for category 1, 2 and 3. Tapered versus non-tapered implants demonstrated only insignificant differences regarding clinical, radiographic, and patient-reported outcomes. The intake of certain selective serotonin reuptake inhibitors and proton pump inhibitors is associated with a statistically significant increased implant failure rate. The intake of bisphosphonates related to the treatment of osteoporosis was not associated with an increased implant failure rate. CONCLUSIONS: It is concluded that short implants (≤6 mm) are a valid option in situations of reduced bone height to avoid possible morbidity associated with augmentation procedures; however, they reveal a higher variability and lower predictability in survival rates. Narrow diameter implants with diameters of 2.5 mm and more demonstrated no difference in implant survival rates compared to standard diameter implants. In contrast, it is concluded that narrow diameter implants with diameters of less than 2.5 mm exhibited lower survival rates compared to standard diameter implants. It is further concluded that there are no differences between tapered versus non-tapered dental implants. Certain medications such as selective serotonin reuptake inhibitors and proton pump inhibitors showed an association with a higher implant failure rate.

Group 5 ITI Consensus Report: Digital technologies.

OBJECTIVES: Working Group 5 was assigned the task to review the current knowledge in the area of digital technologies. Focused questions on accuracy of linear measurements when using CBCT, digital vs. conventional implant planning, using digital vs. conventional impressions and assessing the accuracy of static computer-aided implant surgery (s-CAIS) and patient-related outcome measurements when using s-CAIS were addressed. MATERIALS AND METHODS: The literature was systematically searched, and in total, 232 articles were selected and critically reviewed following PRISMA guidelines. Four systematic reviews were produced in the four subject areas and amply discussed in the group. After emendation, they were presented to the plenary where after further modification, they were accepted. RESULTS: Static computer-aided surgery (s-CAIS), in terms of pain & discomfort, economics and intraoperative complications, is beneficial compared with conventional implant surgery. When using s-CAIS in partially edentulous cases, a higher level of accuracy can be achieved when compared to fully edentulous cases. When using an intraoral scanner in edentulous cases, the results are dependent on the protocol that has been followed. The accuracy of measurements on CBCT scans is software dependent. CONCLUSIONS: Because the precision intraoral scans and of measurements on CBCT scans and is not high enough to allow for the required accuracy, s-CAIS should be considered as an additional tool for comprehensive diagnosis, treatment planning, and surgical procedures. Flapless s-CAIS can lead to implant placement outside of the zone of keratinized mucosa and thus must be executed with utmost care.

Reshaping dental faculty development using collective healthcare experiences.

Dental academics provide a fulfilling career path to educate the next generation of oral health professionals. The number of dentists choosing a career in dental academics is declining and existing faculty are opting for other career options. As the number of dental schools increase across the US, a critical shortage of educators may be evidenced. In dentistry, innovative approaches to develop academic faculty are not keeping pace with the growing needs of dental faculty, who are challenged to establish a fulfilling work-life balance. This work reviews existing methods that other health professions implement to develop faculty for successful career growth. This review highlights factors and related cofactors that influence career development among dental faculty. Recommendations are presented as potential solutions based on the assessment of similar experiences published by related academic healthcare professions. Dental academia must increase attention to faculty needs and awareness by conducting institutional-specific studies to address these issues with customizable solutions.

Using Project Management Principles to Facilitate Interdisciplinary Collaboration.

The impact of interdisciplinary collaboration should always be evaluated from the perspectives of different stakeholders, including patients (and their families/caregivers), healthcare providers, third-party insurance providers, researchers, and companies that provide materials/supplies, to name a few. In an educational environment, the healthcare provider team consists of a dental student/resident and a faculty member. The assessment of outcomes for interdisciplinary collaborations can be multilayered from patient care to education and research. The aim of this article is to review the different layers of assessment (ie, patient care, education, and research) and provide an overview of the benefits and limitations of interdisciplinary care. In addition, the authors compare the varied processes involved in the synergistic care of a patient to a project delivery in an agile environment.

Influence of Implant Diameter and Taper on Virtual Implant Placement in the Maxillary Central Incisor Position: A CBCT Analysis.

PURPOSE: This study aimed to assess the influence of implant diameter and taper on the proximity of virtually planned maxillary central incisor implants to the nasopalatine canal and adjacent anatomical structures. MATERIALS AND METHODS: Virtual implant planning was performed in the maxillary central incisor position. The distance between the implant and the incisive canal (IC) and the thickness of the surrounding buccal and palatal bone walls were measured. Implants were categorized as having an exposed implant surface, thin bone, or moderate/thick bone. Measurements were repeated for regular-/narrow-diameter and parallel/tapered implants. RESULTS: A total of 60 patients were included, and 240 implants (60 of each type: 3.3-bone level [BL], 3.3-bone level tapered [BLT], 4.1-BL, and 4.1-BLT) were planned. The percentages of implants with between 0 and 0.5 mm of remaining bone in the coronal aspect of the IC were 31.6% for 4.1-BL/BLT and 6.6% for 3.3-BL/BLT (P < .001). The percentage of implants with IC exposure was 13.3% for 4.1-BL/BLT and 6.6% for 3.3-BL/BLT (P < .001). The frequency of sites that required bone augmentation at the coronal facial aspect (< 1 mm) was 52.6% and 33.9% for 4.1-BL/BLT and 3.3-BL/BLT, respectively. At the apical portion, the percentages of sites requiring bone augmentation at the facial aspect were 59.9%, 49.9%, 31.6%, and 23.3% for 4.1-BL, 3.3-BL, 4.1-BLT, and 3.3-BLT, respectively (P < .001). CONCLUSION: The proximity of the nasopalatine canal is often < 0.5 mm from regular-diameter virtually planned implants at the most coronal aspect in the maxillary central incisor position. In these situations, the selection of narrowdiameter implants significantly lowers the incidence of implant exposure and the need for additional management of the nasopalatine canal and also results in greater residual buccal and lingual bone thicknesses surrounding the implant. As expected, tapered implants reduced the risk of implant exposure through the buccal cortex at the apical aspect.

Full-Arch Removable vs Fixed Implant Restorations: A Literature Review of Factors to Consider Regarding Treatment Choice and Decision-Making in Elderly Patients.

PURPOSE: To review and analyze the literature regarding removable vs fixed implant prosthetic treatment for complete edentulism in elderly people. MATERIALS AND METHODS: A narrative review of published articles was conducted. Electronic and manual searches were performed to identify studies comparing removable vs fixed implant modalities for edentulous patients and/or reporting on specific outcomes for fixed vs removable implant restorations in elderly patients. RESULTS: It is evident that there are differences in mechanical and biologic maintenance needs due to differences in prosthetic materials and designs for fixed vs removable implant restorations. Anatomical restrictions, age-related problems, lifestyle, cost, maintenance needs, access to dental services, and past experience (both of the provider and the patient) all play a role in prosthesis selection for these patients. Patient expectations and their financial means will define their choices. Patient-reported outcome measures are not standardized, and any assumptions made based on different studies need to be carefully evaluated. CONCLUSION: The decision-making pathway for determining what type of implant-supported prosthesis is preferable for edentulous patients is complicated by many variables that must be considered when treatment planning for maximum benefit for the patient. Detailed explanations of potential outcomes, complications, difficulties, and benefits of therapeutic options is mandatory. Proper assessment of patients' expectations and desires before treatment is critical for a successful outcome.

Recommendations for Implant-Supported Full-Arch Rehabilitations in Edentulous Patients: The Oral Reconstruction Foundation Consensus Report.

The tasks of Working Groups 1 to 6 at the 4th Consensus Meeting of the Oral Reconstruction Foundation were to elucidate clinical recommendations for implant-supported full-arch rehabilitations in edentulous patients. Six systematic/narrative reviews were prepared to address the following subtopics: (1) the influence of medical and geriatric factors on implant survival; (2) the prevalence of peri-implant diseases; (3) the influence of material selection, attachment type, interarch space, and opposing dentition; (4) different interventions for rehabilitation of the edentulous maxilla; (5) different interventions for rehabilitation of the edentulous mandible; and (6) treatment choice and decision-making in elderly patients. Consensus statements, clinical recommendations, and implications for future research were determined based on structured group discussions and plenary session approval.