Implant-Abutment Connections and Their Effect on Implant Survival Rates and Changes in Marginal Bone Levels (Δ): A Systematic Review and Meta-Analysis of 45,347 Oral Implants.

Purpose: To quantify the cumulative oral implant survival rates and changes in radiographic bone levels based on the configuration of the implant-abutment connection type over time. Materials and Methods: An electronic literature search was conducted in four databases (PubMed/MEDLINE, Cochrane Library, Web of Science, and Embase), and records were refereed by two independent reviewers based on the inclusion criteria. Data from included articles were grouped by implant-abutment connection type into four categories ([1] external hex; [2] bone level, internal, narrow cone < 45 degrees; [3] bone level, internal wide cone ≥ 45 degrees or flat; and [4] tissue level) and duration of follow-up (short-term 1 to 2 years, mid-term 2 to 5 years, and long-term > 5 years). Meta-analyses were performed for cumulative survival rate (CSR) and changes in marginal bone level (ΔMBL) from baseline (loading) to last reported follow-up. Studies were split or merged as appropriate based on the implants and follow-up duration in the study and trial design. The study was compiled under PRISMA 2020 guidelines and registered in the PROSPERO database. Results: A total of 3,082 articles were screened. Full-text review of 465 articles resulted in a total of 270 articles (representing 16,448 subjects with 45,347 implants) included for quantitative synthesis and analysis. Mean ΔMBL (95% CI) was as follows: short-term external hex = 0.68 mm (0.57, 0.79); short-term bone level, internal, narrow cone < 45 degrees = 0.34 mm (0.25, 0.43); short-term bone level, internal wide cone ≥ 45 degrees = 0.63 mm (0.52, 0.74); short-term tissue level = 0.42 mm (0.27, 0.56); mid-term external hex = 1.03 mm (0.72, 1.34); mid-term bone level, internal, narrow cone < 45 degrees = 0.45 mm (0.34, 0.56); mid-term bone level, internal wide cone ≥ 45 degrees = 0.73 mm (0.58, 0.88); mid-term tissue level = 0.4 mm (0.21, 0.61); long-term external hex = 0.98 mm, 0.70, 1.25); long-term bone level, internal, narrow cone < 45 degrees = 0.44 mm (0.31, 0.57); long-term bone level, internal wide cone ≥ 45 degrees = 0.95 mm (0.68, 1.22); and long-term tissue level = 0.43 mm (0.24, 0.61). CSRs (95% CI) were: short-term external hex = 97% (96%, 98%); short-term bone level, internal, narrow cone < 45 degrees = 99% (99%, 99%); short-term bone level, internal wide cone ≥ 45 degrees = 98% (98%, 99%); short-term tissue level = 99% (98%, 100%); mid-term external hex = 97% (96%, 98%); mid-term bone level, internal, narrow cone < 45 degrees = 98% (98%, 99%); mid-term bone level, internal wide cone ≥ 45 degrees = 99% (98%, 99%); mid-term tissue level = 98% (97%, 99%); long-term external hex = 96% (95%, 98%); long-term bone level, internal, narrow cone < 45 degrees = 98% (98%, 99%); long-term bone level, internal wide cone ≥ 45 degrees = 99% (98%, 100%); and long-term tissue level = 99% (98%, 100%). Conclusion: The configuration of the implant-abutment interface has a measurable effect on the ΔMBL over time. These changes can be observed over a period of at least 3 to 5 years. At all measured time intervals, similar ΔMBL was noted for external hex and internal wide cone ≥ 45-degree connections, as were internal, narrow cone < 45-degree and tissue-level connections.

Can patients detect peri­implant mucosal inflammation? Results from a multicentre randomized trial.

PURPOSE: The objective of this study was to compare patient-reported outcomes (PROs) of peri­implant soft tissue inflammation and aesthetics around single-tooth implants in the anterior maxillary region with three different implant-abutment interface designs. METHODS: Participants were randomized to one of three different types of implant-abutment interface designs [Conical (CI), flat-to-flat (FI), and Platform Switched (PS)]. Implants and provisional crowns with prefabricated titanium abutments were placed 5 months following extraction and/or ridge augmentation. Permanent ceramic crowns with zirconia abutments were placed after 12 weeks. To assess PROs, appearance and inflammation questionnaires were completed from provisional crown placement to the 3-year follow-up. RESULTS: Tooth appearance at the 3-year follow-up revealed a difference amongst CI, FI and PS implants (p=0.049; Kruskal-Wallis test). PS was rated better than FI (p=0.047) at 1 year for appearance of soft-tissue and satisfaction with colour. There were no differences for self-consciousness, smile and pain/discomfort while eating/hard food items. CONCLUSIONS: Although participants tended to rate the health of mucosa around PS implants as slighty better than the other two implant systems, the differences were minimal and inconsistent. Thus, patient satisfaction in terms self-perceived gingival health and esthetics was high for all 3 systems tested, suggesting that patients are unable to detect mucosal inflammation. CLINICAL SIGNIFICANCE: Patients find it difficult to perceive mucosal inflammation; hence, it is recommended that patients attend implant follow-up visits, even if they do not perceive inflammation. The study suggests that there is a relationship between the PROs and the clinical outcomes of tested implants.

Utilizing an organizational development framework as a road map for creating a technology-driven agile curriculum in predoctoral dental education.

The landscape of dental education is undergoing a paradigm shift from both the learner's and teacher's perspectives. Evolving technologies, including artificial intelligence, virtual reality, augmented reality, and mixed reality, are providing synergistic opportunities to create new and exciting educational platforms. The evolution of these platforms will likely play a significant role in dental education. This is especially true in the wake of calamities like the COVID-19 pandemic during which educational activities had to be shutdown or moved online. This experience demonstrated that it is prudent to develop curricula that are both agile and efficient via creating hybrid courses that provide effective learning experiences regardless of the mode of delivery. Although there is growing interest in incorporating technology into dental education, there are few examples of how to actually manage the implementation of technology into the curriculum. In this paper, we provide a road map for incorporating technology into the dental curriculum to create agility and discuss challenges and possible solutions.

Testing for COVID-19 in dental offices: Mechanism of action, application, and interpretation of laboratory and point-of-care screening tests.

BACKGROUND: The dental office potentially possesses all transmission risk factors for severe acute respiratory syndrome coronavirus 2. Anticipating the future widespread use of COVID-19 testing in dental offices, the authors wrote this article as a proactive effort to provide dental health care providers with current and necessary information surrounding the topic. METHODS: The authors consulted all relevant and current guidelines from the Centers for Disease Control and Prevention and the US Food and Drug Administration, as well as online resources and review articles. RESULTS: Routine COVID-19 screening and triage protocols are unable to detect all infected people. With the advancements in diagnostic tools and techniques, COVID-19 testing at home or in the dental office may provide dentists with the ability to evaluate the disease status of their patients. At-home or point-of-care (POC) tests, providing results within minutes of being administered, would allow for appropriate measures and rapid decisions about dental patients' care process. In this review, the authors provide information about available laboratory and POC COVID-19 screening methods and identify and elaborate on the options available for use by dentists as well as the regulatory requirements of test administration. CONCLUSIONS: Dentists need to be familiar with COVID-19 POC testing options. In addition to contributing to public health, such tests may deliver rapid, accurate, and actionable results to clinical and infection control teams to enhance the safe patient flow in dental practices. PRACTICAL IMPLICATIONS: Oral health care must continue to offer safety in this or any future pandemics. Testing for severe acute respiratory syndrome coronavirus 2 at the POC offers a control mechanism contributing to and enhancing the real and perceived safety of care in the dental office setting.

Characteristics and Detection Rate of SARS-CoV-2 in Alternative Sites and Specimens Pertaining to Dental Practice: An Evidence Summary.

Knowledge about the detection potential and detection rates of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in various body fluids and sites is important for dentists since they, directly or indirectly, deal with many of these fluids/sites in their daily practices. In this study, we attempt to review the latest evidence and meta-analysis studies regarding the detection rate of SARS-CoV-2 in different body specimens and sites as well as the characteristics of these sample. The presence/detection of SARS-CoV-2 viral biomolecules (nucleic acid, antigens, antibody) in different clinical specimens depends greatly on the specimen type and timing of collection. These specimens/sites include nasopharynx, oropharynx, nose, saliva, sputum, bronchoalveolar lavage, stool, urine, ocular fluid, serum, plasma and whole blood. The relative detection rate of SARS-CoV-2 viral biomolecules in each of these specimens/sites is reviewed in detail within the text. The infectious potential of these specimens depends mainly on the time of specimen collection and the presence of live replicating viral particles.

Comparison of 6-mm and 11-mm dental implants in the posterior region supporting fixed dental prostheses: 5-year results of an open multicenter randomized controlled trial.

OBJECTIVE: The aim of this multicenter, randomized controlled trial was to compare the clinical and radiographic outcomes of 6-mm or 11-mm implants, placed in the posterior maxilla and mandible, during a 5-year follow-up period. MATERIALS AND METHODS: Ninety-five patients with adequate bone height for 11-mm implants, were randomly allocated to a 6-mm group (test group with short implants) or an 11-mm group (control group with standard-length implants). Two or three implants of the same length were placed in each patient and after 6 weeks loaded with a splinted provisional restoration. This was followed by definitive splinted restoration 6 months after implant placement. Clinical and radiographic parameters, including the occurrence of complications were recorded. RESULTS: A total of 49 patients were enrolled to receive 6-mm implants (n = 108) and 46 patients to receive 11-mm implants (n = 101). Three implants (two of 6 mm and one of 11 mm in length) were lost before loading and one 6-mm implant after 15 months of function, and one 11-mm implant was lost during the first year of function. The 5-year survival rates were 96.0% and 98.9% in the 6-mm and 11-mm group, respectively. The mean marginal bone level changes 5 years post-loading were 0.01 ± 0.45 mm (bone gain) in the 6-mm group and -0.12 ± 0.93 mm (bone loss) in the 11-mm group (p = .7670). Clinical parameters, including plaque, bleeding on probing and pocket probing depth were not significantly different between the groups, and also technical complications were low. CONCLUSION: The clinical and radiographic outcomes of 6-mm short and 11-mm standard-length implants were not different during a 5-year evaluation period.

Female Caregivers' Depression Risk Affects Children's Attendance to Dental Appointments: A Pilot Study.

Purpose: This pilot study aimed to evaluate the association between women's depression risk and their children's return for dental treatment. Methods: A total of 175 female caregivers of children presenting for an initial dental examination between May and October 2019 at a university clinic answered demographic questions and a validated survey on depression risk. An analysis of caregiver's depression risk relative to children's attendance at the next treatment appointment was made. Results: One hundred and eight female caregivers were included in the analysis. Average age was 33 years (standard deviation ± 6.5 years), and 52 percent were Hispanic. The rate of risk for depression was 17.5 percent. Most women at risk lived at least 20 miles away, had an income of less than $29,999, were unemployed or employed part-time, and had no help with childcare. White caregivers were more likely to fail to attend their child's appointment (chi-square [X²] = 7.80, P=0.02) while Hispanic women were more likely to return (X² = 4.10, P=0.04). Caregivers with low depression risk were more likely to return for the child's scheduled appointment (X² = 13.37, P<0.001). Thus, there was a positive association between high depression risk and failed appointments (r=0.474, P<0.01). Conclusion: Children of women at risk for depression are more likely to fail to attend their dental appointment.

Pink Esthetic Score Outcomes Around Three Implant-Abutment Configurations: 3-Year Results.

PURPOSE: To evaluate the influence that three different implant-abutment interface designs had on peri-implant mucosal outcomes as assessed by the pink esthetic score (PES) 3 years after delayed implant placement and immediate provisionalization. MATERIALS AND METHODS: Adult subjects (n = 141) requiring replacement of a bounded single tooth in the anterior maxilla as well as first premolar sites were randomized to receive one of three unique implant-abutment interface designs (conical interface [CI]; flat-to-flat interface [FI]; or platform-switch interface [PS]). Treatment included immediate provisionalization with prefabricated titanium abutments, followed by custom computer-aided design/computer-aided manufacturing (CAD/CAM) zirconia abutments and cement-retained, all-ceramic crowns delivered after 12 weeks. Bilateral (anterior sites) or unilateral (premolar sites) digital clinical photographs were made at 1, 3, 6, 12, 24, and 36 months post-implant placement. Five calibrated faculty evaluators who previously scored the 1-year PES image dataset scored the 24- and 36-month photographs using a digital, cloud-based tablet interface. RESULTS: Six hundred ten clinical photographs were evaluated, resulting in a total of 3,050 sum PES values and 21,350 individual PES values. Faculty evaluator intrarater and interrater reliability were found to be "substantial," with intraclass correlation coefficient (ICC) values of 0.76 and 0.77, respectively. All three implant-abutment interface groups demonstrated acceptable esthetics at 3 years (mean sum PES = 10.1 ± 1.9, 4.0 to 13.2), with no single group demonstrating significantly greater mean sum PES values than another at the 3-year follow-up or at any recall interval in between. CONCLUSION: No significant differences were observed in mean sum PES scores for subjects randomized to one of three different implant-abutment interface geometries. Within the limitations of this study thus far, the first 6 months following definitive prosthesis delivery appear to still be the most significant with regard to improvement in PES outcomes for all three treatment groups.

Marginal bone level and survival of short and standard-length implants after 3 years: An Open Multi-Center Randomized Controlled Clinical Trial.

OBJECTIVES: The present multi-center randomized controlled clinical trial sought to compare the marginal bone level (MBL) changes and survival of 6- and 11-mm implants. MATERIAL AND METHODS: Ninety-five patients receiving a total of 209 dental implants were enrolled. Subjects were randomly allocated to two cohorts: test (4.0 × 6 mm; N = 108) or control (4.0 × 11 mm; N = 101) implant groups. To be randomized, all edentulous sites were anatomically qualified to receive 11 mm implant. Two to three implants were placed in maxillary or mandibular posterior regions and loaded with splinted provisional restoration after 6 weeks and definitive restoration 6 months thereafter. Test and control implants were followed by clinical and radiographic examinations on an annual basis up to 3 years. RESULTS: Radiographic assessment of MBL 3 years after loading revealed the bone to be located at 0.27 mm (±0.40) and 0.44 mm (±0.74) apical to the implant platform in the test and control groups, respectively. During the 3 years of follow-up since loading, 0.04 mm (±0.43) MBL gain and 0.02 mm (±0.76) of MBL loss were observed in the 6-mm (test) and 11-mm (control) groups, respectively. The MBL's for test and control were significantly different (p = 0.000) in favor of short implants. The cumulative survival rates from placement after 3 years were 96% and 99% for the 6- and 11-mm implants, respectively, with no statistical significance. CONCLUSIONS: Reconstruction of partially edentulous posterior maxilla or mandible with 6- or 11-mm implants led to stable marginal bone level and high implant survival rate after 3 years.

Multicenter Clinical Randomized Controlled Trial Evaluation of an Implant System Designed for Enhanced Primary Stability.

PURPOSE: This intention-to-treat (ITT) non-inferiority multicenter study was performed to evaluate implant system design, surgical and prosthetic aspects, and the effect on marginal bone levels of two related implant systems. Implant design alterations consisted of modifications in implant body shape and abutment connections. Drilling procedures and drill design were adapted to the implant design. MATERIALS AND METHODS: Five clinics participated in this study; all had institutional review board approval. Two versions of the implant system were used: test and predicate. One hundred twenty partially dentate subjects with healed sites were randomized to either test or predicate implants. Fifty-nine subjects received 79 test implants and 61 received 87 predicate implants. Bone classification, insertion torque values (ITV), and the surgeon's perception of primary stability were recorded. Definitive restorations with a titanium abutment were made approximately 6 to 8 weeks following implant placement. All restorations were cement retained. Marginal bone levels were evaluated on radiographs at implant placement, at restoration, and at 6 and 12 months postloading. RESULTS: Most subjects received one implant placed in the premolar or molar area (95% of sites). Fifty-three percent of the implants were placed in the maxilla. Median ITV at placement was 31 ± 13 Ncm for the test system and 22 ± 9 Ncm for predicate system, respectively. Time to loading was similar (test, 63.1 ± 24.8; predicate, 62.9 ± 26.9 days). Mean marginal bone loss 12 months after functional loading was 0.07 ± 0.73 mm in the test group and 0.03 ± 0.84 mm in the predicate group, with no statistically significant difference (P = .6895). Five implants were lost (four test, one predicate) from implant placement, all within the first 8 weeks following placement; none were restored. The 1-year postloading cumulative implant survival rate was 94.9% (73 implants at risk) for the test system and 98.9% (84 implants at risk) for the predicate system. CONCLUSION: Treatment with the test implant system, utilizing its bone classification for guidance regarding drilling protocol, resulted in enhanced implant stability. Marginal bone levels were stable 12 months after functional loading.

Academy of Osseointegration's Summit on Clinical Practice Guidelines for the Edentulous Maxilla: Overview, Process, and Outcomes-Changing the Face of Implant Dentistry.

PURPOSE: Starting in 2012, the Academy of Osseointegration initiated the planning process for an AO Summit to develop clinical practice guidelines (CPGs) for management of the edentulous maxilla. MATERIALS AND METHODS: A planning committee led by Professor Clark Stanford and Dr Ole Jensen created a work plan based on five domain areas to be addressed by the summit. The five domain areas were defined as: (1) role of grafting for ridge development for implant placement, (2) role of implant design and systems in management of the edentulous maxilla, (3) role of imaging to guide implant placement, (4) role of biologics to assist in ridge development, and (5) role of prosthetic management. RESULTS: The summit was held in August 2014, and the results are presented in this overview. All of the supporting systematic reviews and the detailed CPGs are presented in this special edition of JOMI. CONCLUSION: While the evidence was observed to be weak in regard to the literature for most of the systematic reviews, the summit strived to establish the current best evidence and practical CPGs that will assist clinicians in practice.

Electronic assessment of peri-implant mucosal esthetics around three implant-abutment configurations: a randomized clinical trial.

OBJECTIVES: To objectively assess the influence that three different implant-abutment interface designs had on peri-implant mucosal esthetics at 1 year post-implant placement via the pink esthetic score (PES). Additionally, to demonstrate the novel employment of a tablet-based digital imaging format to reliably assess and score clinical images as part of a multicenter clinical trial according to PES criteria. MATERIALS AND METHODS: Adult subjects (n = 141) with healed tooth-bound edentulous sites in the anterior maxilla as well as first premolar region were randomized to receive one of three different implant-abutment interface designs (conical interface = CI; flat-to-flat interface = FI; or platform switch interface = PS). Immediate provisionalization was performed with prefabricated titanium abutments, with definitive custom CAD/CAM zirconia abutments and all-ceramic cement-based crowns being delivered 12-week post-implant placement. Bilateral (anterior sites) or unilateral (premolar sites) digital clinical photographs were made at 1, 3, 6, and 12 months post-implant placement. Five calibrated faculty evaluators of different clinical backgrounds scored images during a 4-week timeframe on a standardized, tablet-based, digital imaging format. RESULTS: Six hundred and forty-nine clinical photographs were evaluated resulting in a total of 3245 sum PES values and 22,715 individual PES values. Faculty evaluator intra- and inter-rater reliability was found to be "strong" (ICC = 0.84) and "substantial" (ICC = 0.64), respectively, demonstrating repeatability of both the PES, evaluator calibration, and standardization of tablet-based scoring. All implant-abutment interface groups demonstrated significant improvements in mean sum PESs up to 1 year, with the largest improvement between restoration delivery and 6 months. No significant differences were found between groups in mean sum PESs both for individual study visits as well as for changes between study visits. CONCLUSIONS: No significant differences in mean sum PESs were found between subjects randomized to three different implant-abutment interfaces. However, significant differences were found as a function of time for all three groups, with the largest improvement in mean sum PESs occurring between definitive abutment and restoration delivery and 6 months. Use of electronic, tablet-based digital imaging scoring formats represents a novel and repeatable methodology for scoring PES images in large, multicenter clinical trials.

Esthetic outcomes in relation to implant-abutment interface design following a standardized treatment protocol in a multicenter randomized controlled trial--a cohort of 12 cases at 1-year follow-up.

The design of an implant-abutment interface may have an impact on the peri-implant soft tissue esthetics. In an ongoing randomized controlled trial (RCT) with 141 participants, the authors evaluated the peri-implant tissue responses around three different implant-abutment interface designs used to replace single teeth in the esthetic zone. The aim of this report is to describe the treatment protocol utilized in this ongoing RCT by (1) demonstrating in detail a clinical case treated under this protocol and (2) reporting peri-implant soft tissue responses in a cohort of 12 representative cases from the RCT at 1-year follow-up. Male and female adults requiring single implants in the anterior maxilla were enrolled in the RCT according to the study protocol. Five months following any required extraction and/or socket bone grafting/ridge augmentation, one of the following three implant-abutment interfaces was placed and immediately provisionalized: (1) conical interface (CI; OsseoSpeed, Dentsply Implants), n = 4; (2) flat-to-flat interface (FI; NobelSpeedy Replace, Nobel Biocare), n = 4; or (3) platform-switch interface (PS; NanoTite Certain Prevail, Biomet 3i), n = 4. Twelve weeks later, definitive crowns were delivered. Throughout the treatment, peri-implant buccal gingival zenith height and mesial/distal papilla height were measured on stereotactic device photographs, and pink esthetic scores (PES) were determined. The demographics of the participants in each of the three implant-abutment interface groups were very similar. All 12 study sites had ideal ridge form with a minimum width of 5.5 mm following implant site development performed according to the described treatment protocol. Using this treatment protocol for single-tooth replacement in the anterior maxilla, the clinicians were able to obtain esthetic peri-implant soft tissue outcomes with all three types of implant-abutment interface designs at 1-year follow-up as shown by the Canfield data and PES. The proposed treatment protocol for single-tooth replacement in the esthetic zone provides a reliable method to obtain and assess the esthetic outcome as a function of implant-abutment interface design and is now in its fifth year of follow-up.

Comparison of pro-inflammatory cytokines and bone metabolism mediators around titanium and zirconia dental implant abutments following a minimum of 6 months of clinical function.

OBJECTIVES: Dental implant abutments are fundamental prosthetic components within dentistry that require optimal biocompatibility. The primary aim of this cross-sectional study was to preliminarily assess differences in the pro-inflammatory cytokine and bone metabolism mediator protein expression in the peri-implant crevicular fluid (PICF) adjacent to transmucosal abutments. MATERIAL AND METHODS: Abutments were fabricated from either titanium or zirconia in patients previously receiving single-tooth implant therapy. All subjects sampled in this study had an identical implant system and implant-abutment connection. Participants (n = 46) had an average time of clinical function for 22 months (6.2-72.8 months, ±SD 17 months) and received a clinical and radiographic examination of the implant site at the time of PICF sampling using a paper strip-based sampling technique. Cytokine, chemokine, and bone metabolism mediator quantities (picograms/30 s) were determined using a commercial 22-multiplexed fluorescent bead-based immunoassay instrument. A total of 19 pro-inflammatory cytokines and seven bone metabolism mediators were evaluated. RESULTS: Multivariable analyses provided no evidence of a group (titanium or zirconia), gender, or age effect with regard to the expression of pro-inflammatory mediators evaluated. Significant (P = 0.022) differences were observed for the bone mediator leptin, with titanium abutments demonstrating significantly elevated levels in comparison with zirconia. Osteopontin demonstrated a significant (P = 0.0044) correlation with age of the subjects. CONCLUSIONS: No significant differences in pro-inflammatory cytokine or bone metabolism mediator profiles were observed biochemically, with the exception of leptin, for the abutment biomaterials of titanium or zirconia The molecular PICF findings support the observed clinical biocompatibility of both titanium and zirconia abutments.