Nevin Manimala

Int J Oral Maxillofac Implants. 2023 Oct 17;38(5):1014-1024. doi: 10.11607/jomi.10225.

ABSTRACT

PURPOSE: To compare the fit of 3D-printed titanium (Ti) and cobalt-chromium (Co-Cr) abutments with implants to computer numerical control (CNC)-milled, ready-made abutment-implant assemblies. Their clinical applicability was also evaluated by measuring removal torque values (RTVs) and percentage torque loss of abutment screws.

MATERIALS AND METHODS: A total of 138 abutments were included in the study: 92 abutments were fabricated with Ti and Co-Cr alloys using computer-assisted design (CAD) through selective laser melting, and 46 ready-made abutments were prepared. The fit of interfaces between 90 abutments from the three groups (30 ready-made, 30 3D-printed Ti, and 30 3D-printed Co-Cr abutments) and implant assemblies was demonstrated by scanning electron microscopy (SEM) and confocal scanning laser microscopy (CSLM). After 30-Ncm torque tightening of Ti abutment screws twice within 10 minutes, the RTVs and percentage torque loss of screws of 48 abutments (16 ready-made, 16 3D-printed Ti, and 16 3D-printed Co-Cr) were evaluated after 10 minutes of thermocycling and cyclic loading.

RESULTS: The fits of 3D-printed Co-Cr abutments were not statistically different from those of ready-made abutments (P = .383), while the fit of 3D-printed Ti abutments was inadequate (P < .001). The RTVs of 3D-printed abutments after cyclic loading were significantly decreased compared with those of CNC-milled abutments (P < .001).

CONCLUSION: The fit of interfaces between 3D-printed Co-Cr abutments and implants was adequate. The RTVs of 3D-printed Co-Cr abutments were not significantly different from those of CNC-milled abutments after 10 minutes of 30-Ncm torque tightening and thermocycling.

PMID:37847843 | DOI:10.11607/jomi.10225

Int J Oral Maxillofac Implants. 2023 Oct 17;38(5):985-995. doi: 10.11607/jomi.10311.

ABSTRACT

PURPOSE: To evaluate the peri-implant outcomes of customized healing abutments (CstHA) placed on dental implants inserted in fresh tooth extraction sockets.

MATERIALS AND METHODS: The study was registered on PROSPERO: CRD42022304320. A systematic search in PubMed, Scopus, and Web of Science was conducted between April 2022 and October 2022 to identify clinical studies involving immediate implant surgery associated with CstHA placement. The Joanna Briggs Institute Critical Appraisal and RoB2 tool were performed for the risk of bias analysis.

RESULTS: A total of 12 studies were included, most of them with low risk of bias. Four studies compared CstHA vs conventional healing abutments (CnvtHA), two compared CstHA vs cover screw and collagen matrix (CMa), and six were clinical case series. For the CstHA vs CnvtHA comparison, favorable results were observed for CstHA considering papilla maintenance and probing depth, yet the mean marginal bone level was statistically similar between CstHA and CnvtHA. CstHA showed advantages when compared to CMa for total bone volume, papilla height, and midfacial mucosa maintenance. Significantly less horizonal bone loss was reported when using CstHA compared with CMa. Horizontal and vertical bone loss was observed in a few (or no) sites in the case series using CstHA.

CONCLUSIONS: CstHA provides favorable peri-implant response because in general it does not result in a significant loss of soft and hard tissues.

PMID:37847840 | DOI:10.11607/jomi.10311

Int J Oral Maxillofac Implants. 2023 Oct 17;38(5):963-975. doi: 10.11607/jomi.10258.

ABSTRACT

PURPOSE: To evaluate the survival rate (primary outcome) and the marginal bone loss (secondary outcome) of the OsseoSpeed EV Implants (Astra Tech Implant System, Dentsply Sirona Implants; hereinafter EV implants) used in a wide range of clinical scenarios and followed up to 8 years in a nonuniversity setting.

MATERIALS AND METHODS: All EV implants consecutively placed from 2013 to 2021 in a private dental clinic were included, and medical and radiologic records were retrospectively investigated. Independent reviewers collected 11 data types as potential influencing variables and measured the mesial and distal marginal bone levels to the nearest 0.5 mm on available radiographs, either panoramic or periapical. Tables of descriptive statistics were made at implant and patient levels. Univariate and multiple Cox regression models were adjusted for clustering effects and determined the hazard ratio (HR) and odds ratio (OR) for each independent variable collected.

RESULTS: The study sample consisted of 597 EV implants and 235 patients. During a mean follow-up of 42.1 ± 23 months (range: 10 to 94 months), 44 implants were lost (7.4%)-34 early (5.7%) and 10 late (1.7%)-in 38 patients (16.1%). The overall survival rate (SR) was 92.6% (CI: 90.5% to 94.7%), and the proportion of patients with all their implants surviving was 83.8% (CI: 79.1% to 88.5%). At the end of the study, the probability of survival of an implant that did not fail early was 98.2% (CI: 97.1% to 99.3%). Implant-level analysis identified two significant variables: implant diameter (HR 0.37, P = .009**) and immediate postextraction placement (HR 2.35, P = .025*). At the patient level, bruxism (OR = 3.29; P = .009**), history of periodontitis (OR = 2.18, P = .030*), and the number of implants placed (OR = 1.43; P = .001**) were found to be statistically significant. After removing dropouts and early failures from a sample of 528 implants, 412 (78%) had a marginal bone loss (MBL) ≤ 0 mm at the end of the observation time, and 106 surviving implants (22%) showed a mean MBL of 1.42 ± 1.08 mm (range: 0.25 to 6.75 mm).

CONCLUSIONS: An overall medium-term SR of the EV implants was 92.6%. Four of five EV implants showed a mid-term MBL ≤ 0 mm, and 91.86% of implants completed the observation period with an MBL < 2 mm. Thus, the EV implant system was shown to be a valid alternative for routine use in a nonuniversity setting. Clinicians should remember that there is no 100% implant survival in everyday practice and that bruxism, periodontitis, narrow-diameter implants, and immediate placement are risk factors for a higher failure rate.

PMID:37847838 | DOI:10.11607/jomi.10258

Int J Oral Maxillofac Implants. 2023 Oct 17;38(5):943-953. doi: 10.11607/jomi.10276.

ABSTRACT

PURPOSE: To evaluate the bone level changes in a new implant design (fully tapered with platform switching) with the one-abutment one-time protocol after 1 year of loading.

MATERIALS AND METHODS: Thirty patients received 1 or 2 implants (6-, 8-, or 10-mm length and 3.5-, 3.75-, or 4.5-mm diameter, bone-level design) to replace one or multiple edentulous sites. Only the mesial implant was assessed. Radiographic, clinical, and esthetic results and the survival and success rates were evaluated 1 year after final loading.

RESULTS: At 1 year, no peri-implant bone loss was seen in any of the cases. Mean marginal crestal bone loss between surgery and crown placement was 0.19 ± 0.17 mm (P < .0001). Between surgery and the 1-year follow-up, the mean marginal crestal bone loss was 0.25 ± 0.24 mm (P < .0001). The difference in the modified Plaque Index between 1 year of follow-up and crown placement was significant for in the mesial (0.33 ± 0.54 mm; P = .003) and distal surfaces (0.5 ± 0.73 mm; P = .001). The probing pocket depth was statistically significantly deeper at 1 year than at crown placement at the mesial and distal aspects (average depth = 0.75 mm; P < .0005). No statistically significant differences were found for any other clinical or esthetic parameters. The overall survival and success rates after 1 year were 100%.

CONCLUSIONS: The fully tapered, deep-thread, platform-switched implant design placed with the one-abutment one-time protocol demonstrated minimal marginal crestal bone loss and crestal bone stability at 1 year of follow-up.

PMID:37847836 | DOI:10.11607/jomi.10276

Int J Oral Maxillofac Implants. 2023 Oct 17;38(5):923-932. doi: 10.11607/jomi.9822.

ABSTRACT

PURPOSE: To compare bone substitutes composed of glycated collagen with synthetic micro-sized (1 to 10 μm) hydroxyapatite (OB) vs non-cross-linked collagen matrix with large-particle (250 to 1,000 μm) bovine-derived hydroxyapatite (BOC).

MATERIALS AND METHODS: The P1 to P4 premolars were bilaterally extracted from the mandibles of 19 Beagle dogs. After 21 days, osteotomies were created in each dog that received OB or BOC and were covered with a collagen membrane or were left untreated. The animals were randomly divided into three groups based on sacrifice time (4, 12, or 24 weeks). The right and left hemimandibles were trimmed to facilitate imaging and histology, and all tissues were placed in 10% neutral-buffered formalin. Microcomputed tomography (MicroCT 40 Scanner, Scanco) was used to analyze bone sections. Bone volume, residual material volume, and bone mineral density were determined for each treatment site (OB and BOC) based on a volume of interest that encompassed the original defect. Additionally, blinded histopathologic assessment (based on the ISO 10993-6 scoring system) and histomorphometry were performed on sections ground to < 100 μm thick and stained with Stevenel’s blue.

RESULTS: No clinical side effects were noted. No statistical differences were observed for OB vs BOC regarding the mineral volume percentage. Compared to OB, BOC had significantly higher mean mineralization densities at 12 weeks (P < .01), but this difference did not extend to 24 weeks. For residual grafting material, bone maturation, alveolar ridge restoration, and inflammatory response, OB showed a residual amount of bone graft and no statistical differences compared to BOC.

CONCLUSION: Both OB and BOC represent valid treatment options for critically sized bone defects. Both bone fillers outperformed the sham-operated, ungrafted (empty) control, demonstrating statistically improved bone growth and ridge restoration.

PMID:37847834 | DOI:10.11607/jomi.9822

Int J Oral Maxillofac Implants. 2023 Oct 17;38(5):847-854. doi: 10.11607/jomi.10480.

ABSTRACT

It is important for dental researchers to have a general idea of the different types of data that can be collected from a study and the available statistical tools that can be used with such data. By knowing about what is available, researchers will have an informed idea of the types of studies that should be conducted, the data that should be collected, and the proper statistical methods for analyzing collected data. In the first part of this general overview of statistical methods, we walked through the various types of data that traditional statistical techniques, such as t tests and linear regression, can handle. In this second part, we explore more complex types of data that traditional statistical techniques are unable to handle. Specifically, we discuss longitudinal and time-to-event data because both occur frequently in dental studies and require special modeling techniques in order to analyze correctly. Using two different simulated dental datasets, the proper application of techniques such as repeated measures ANOVA, linear mixed modeling, generalized estimating equations, log-rank test, and Cox proportional hazards models are discussed and illustrated in depth.

PMID:37847827 | DOI:10.11607/jomi.10480

Age Ageing. 2023 Oct 2;52(10):afad191. doi: 10.1093/ageing/afad191.

ABSTRACT

BACKGROUND: Falls in older people are common, leading to significant harm including death. Coroners have a duty to report cases where action should be taken to prevent future deaths, but dissemination of their findings remains poor.

OBJECTIVE: To identify preventable fall-related deaths, classify coroner concerns and explore organisational responses.

DESIGN: A retrospective systematic case series of coroners’ Prevention of Future Deaths (PFD) reports, from July 2013 (inception) to November 2022.

SETTING: England and Wales.

METHODS: Reproducible data collection methods were used to web-scrape and read PFD reports. Demographic information, coroner concerns and responses from organisations were extracted and descriptive statistics used to synthesise data.

RESULTS: Five hundred and twenty-seven PFDs (12.5% of PFDs) involved a fall that contributed to death. These deaths predominantly affected older people (median 82 years) in the community (72%), with subsequent death in hospital (70.8%). A high proportion of cases experienced fractures (51.6%), major bleeding (35.9%) or head injury (38.7%). Coroners frequently raised concerns regarding falls risks assessments (20.9%), failures in communication (20.3%) and documentation issues (17.5%). Only 56.7% of PFDs received a response from organisations to whom they were addressed. Organisations tended to produce new protocols (58.5%), improve training (44.6%) and commence audits (34.3%) in response to PFDs.

CONCLUSIONS: One in eight preventable deaths in England and Wales involved a fall. Addressing concerns raised by coroners should improve falls prevention and care following falls especially for older adults, but the poor response rate may indicate that lessons are not being learned. Wider dissemination of PFD findings may help reduce preventable fall-related deaths in the future.

PMID:37847796 | DOI:10.1093/ageing/afad191

Int J Prosthodont. 2023 Oct 17;0(0):0. doi: 10.11607/ijp.8720. Online ahead of print.

ABSTRACT

PURPOSE: To investigate the microscopic structure and fracture toughness of two pressable glass-ceramics comprising GC Initial LiSi Press (LiSi) and IPS e.max Press (e.max) with different levels of translucency.

MATERIALS AND METHODS: Four groups of LiSi and e.max with medium opacity and high translucency levels were examined. The crystal morphology of acid-etched specimens was observed under a scanning electron microscope (SEM). Six specimens in each group were fabricated in square shape (12 mm ’12 mm ‘ 1.5 mm) to measure translucency parameters (TP) using a spectrophotometer. Ten bar-shaped specimens each group with dimension of 23 mm ‘ 2 mm ‘ 4 mm were determined the fracture toughness (KIc) by a surface crack in flexure (SCF) using a universal testing machine. One-way ANOVA and Scheffe post-hoc tests were used for statistical analysis.

RESULTS: LiSi showed fine dense crystals 1 – 1.5 µm in size, while e.max showed long rod-shaped crystals 3 – 4 µm in size. The TP values of all specimens were coincided with their translucency levels.There was no statistical difference in the KIc between different translucency for both ceramics (p<0.05). However, the KIc of e.max was significantly higher than that of LiSi at both translucency levels. As a result of larger and longer crystals in e.max, it could provide better crack deviation mechanism to resist the fracture.

CONCLUSION: Within the limitations of this study, the translucency levels of both lithium disilicate ceramics did not affect the fracture toughness of the materials. The fracture toughness of e.max was statistically higher than LiSi.

PMID:37847790 | DOI:10.11607/ijp.8720

Int J Prosthodont. 2023 Oct 17;0(0):0. doi: 10.11607/ijp.8405. Online ahead of print.

ABSTRACT

PURPOSE: This study aims to evaluate the effect of different finishing protocols on the wear behavior of a lithium disilicate glass-ceramic.

MATERIAL AND METHODS: Specimens were produced from lithium disilicate glass-ceramic prefabricated CAD/CAM blocks and divided into three groups, according to the surface treatment (n = 8): control; polishing; glaze. Ceramic specimens were subjected to wear test using a dual-axis chewing simulator. A 49 N load was applied in the axial direction combined with a lateral movement (1 mm path) using a lithium disilicate glass-ceramic spherical piston for a total of 106 cycles. Qualitative analysis of the wear surface was performed using an optical microscope. Quantitative analysis of surface roughness and volume loss was performed using a confocal microscope and a 3D-image editing software, respectively. Surface roughness and volume loss data were analyzed using Friedman’s non-parametric statistical test for repeated measures and the Student-Newman-Keuls test (α = 0.050).

RESULTS: There were statistical differences for surface roughness and volume loss of lithium disilicate glass-ceramic specimens in the different experimental conditions (P˂0.001). Control and polishing groups showed similar surface roughness and volume loss values for all testing times. Glaze group had greater wear volume after 103, 104 and 105 cycles. After 106 cycles, surface roughness and volume loss were similar among groups. For the piston, surface roughness was similar over time and among groups.

CONCLUSIONS: A distinct wear behavior was found for glazed glass-ceramic specimens in comparison to control and polished specimens. The end of the simulation, the surface roughness and volume loss was similar for the groups.

PMID:37847788 | DOI:10.11607/ijp.8405

JMIR Ment Health. 2023 Oct 17;10:e46518. doi: 10.2196/46518.

ABSTRACT

BACKGROUND: Cross-sectional relationships between psychosocial resilience factors (RFs) and resilience, operationalized as the outcome of low mental health reactivity to stressor exposure (low “stressor reactivity” [SR]), were reported during the first wave of the COVID-19 pandemic in 2020.

OBJECTIVE: Extending these findings, we here examined prospective relationships and weekly dynamics between the same RFs and SR in a longitudinal sample during the aftermath of the first wave in several European countries.

METHODS: Over 5 weeks of app-based assessments, participants reported weekly stressor exposure, mental health problems, RFs, and demographic data in 1 of 6 different languages. As (partly) preregistered, hypotheses were tested cross-sectionally at baseline (N=558), and longitudinally (n=200), using mixed effects models and mediation analyses.

RESULTS: RFs at baseline, including positive appraisal style (PAS), optimism (OPT), general self-efficacy (GSE), perceived good stress recovery (REC), and perceived social support (PSS), were negatively associated with SR scores, not only cross-sectionally (baseline SR scores; all P<.001) but also prospectively (average SR scores across subsequent weeks; positive appraisal (PA), P=.008; OPT, P<.001; GSE, P=.01; REC, P<.001; and PSS, P=.002). In both associations, PAS mediated the effects of PSS on SR (cross-sectionally: 95% CI -0.064 to -0.013; prospectively: 95% CI -0.074 to -0.0008). In the analyses of weekly RF-SR dynamics, the RFs PA of stressors generally and specifically related to the COVID-19 pandemic, and GSE were negatively associated with SR in a contemporaneous fashion (PA, P<.001; PAC,P=.03; and GSE, P<.001), but not in a lagged fashion (PA, P=.36; PAC, P=.52; and GSE, P=.06).

CONCLUSIONS: We identified psychological RFs that prospectively predict resilience and cofluctuate with weekly SR within individuals. These prospective results endorse that the previously reported RF-SR associations do not exclusively reflect mood congruency or other temporal bias effects. We further confirm the important role of PA in resilience.

PMID:37847551 | DOI:10.2196/46518