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Abstract Cholesteric liquid crystals exhibit a periodic helical structure that partially reflects light with wavelengths comparable to the period of the structure, thus performing as a one-dimensional photonic crystal. Here, we demonstrate a combined experimental and numerical study of light transmittance spectra of finite-length helical structure of cholesteric liquid crystals, as affected by the main system and material parameters, as well as the corresponding eigenmodes and frequency eigenspectra with their Q-factors. Specifically, we have measured and simulated transmittance spectra of samples with different thicknesses, birefringences and for various incident light polarisation configurations as well as quantified the role of refractive index dispersion and the divergence of the incident light beam on transmittance spectra. We identify the relation between transmittance spectra and the eigenfrequencies of the photonic eigenmodes. Furthermore, we present and visualize the geometry of these eigenmodes and corresponding Q-factors. More generally, this work systematically studies the properties of light propagation in a one-dimensional helical cholesteric liquid crystal birefringent profile, which is known to be of interest for the design of micro-lasers and other soft matter photonic devices. more...

Abstract The presence of optical anisotropy in liquid crystals (LCs) has caused these materials to have dual refractive indices: ordinary (no) and extra-ordinary (ne). Many fundamental information about LCs can be found by looking at these refractive indices. In this work, the refractive indices of four mixtures nematic liquid crystal (NLC) have been studied as a function of temperature, and the relevant functions were then calculated. Subsequently, the order parameter of mentioned LCs was determined using three methods: Vuks, Haller, and the effective geometry parameter method. It was concluded that the obtained values are not significantly different and exhibit the same temperature dependence. The obtained results were evaluated in relation to the approach utilized. more...

We study the effects of nanoparticles (NPs) on thermotropic nematic liquid crystals (LCs) in relatively dilute NP–LC mixtures. We are interested in the fundamental generic mechanisms that quantitatively and qualitatively affect the phase behavior of LCs. A simple molecular field analysis shows that a phase transition will likely occur upon entry into the ordered phase. Moreover, the interaction between nematogenic NPs and LCs could force a sergeant–soldier-like behavior, in which only the phase behavior of one component is affected despite the symmetric appearance of the coupling term. When NPs are anisotropic, their influence on LC phase behavior can be qualitatively different depending on the anchoring, even in the absence of the disorder. We illustrate numerically that a random-field-type disorder might impose either short-range, quasi-long-range, or even long-range order, which might survive. more...

Conventional implant dentistry has been limited to healed edentulous ridges with adequate bone. Predictable success rates resulted in using dental implants in compromised situations such as insertion into old infected sites or near to pathological areas. There is significant data about marginal bone loss and lack of osseointegration around the neck of implants. However, the data about peri apical implant bone loss is really rare. An electronic search was carried in PubMed regarding articles in the time period from 1980 to 2011. Subsequent manual search was performed included all animal and human case series and clinical trials. Reported success rates and treatment options were calculated in a systematic manner. There is conflicted data showing a relatively accepted success of implantation immediately after removal of infection directly or indirectly in contact with the apical portion of the implants. However, some complications may happen that must be managed. The available data about the periapical implant pathologies is relatively inadequate. However, concluded data represents some clinical comments in order to reduce the complexities. [ABSTRACT FROM AUTHOR] more...

Generally, Mechanical systems, such as cars, are comprised of various subsystems. These subsystems have specific functional purpose and collectively contribute to the overall performance of the system. The behavior of the isolated subsystem (substructure) subjected to dynamic loading is different than the behavior of the same substructure within the system (structure). This is caused primarily by the boundary conditions imposed on the substructure from the surrounding subsystem. This work presents on the development of a technique for performing substructure analysis on isolated substructures using finite element Analysis (FEA). Here we propose an approach in substructural testing that produces similar results between a substructure in isolation and a substructure in situ using FEA. The developed technique is based on enforcing the mode shapes around the boundary of the substructure in the full structure (referred to as subfull) onto the boundary of isolated substructure. This is achieved by providing a consistent adjustment to the loading conditions to account for the loss of restraint at the interface with the full structure. The advantage of the proposed techniques is that it lends itself to experimental work. [ABSTRACT FROM AUTHOR] more...

Numerical investigations were performed on a series of laminated composites when subjected to dynamic loadings, in order to determine their energy absorption rate and dissipating energy during impact. The details of numerical modeling, contact analysis, material parameters, and failure criteria were explained and discussed. We aimed to determine the energy absorption rate of various quasi-isotropic lay-ups when subjected to the dynamic loadings, and found that energy dissipation rate varied depending on stacking sequence. In this investigation, we studied how the energy absorption rate and the peak impact load change as a result of changing stacking sequence, with all stacking sequences being quasi-isotropic. Using a constant impacting mass and varied impacting speeds, we found that stacking sequence can significantly control the energy transfer rate or energy absorption rate under dynamic load condition. more...

120 Cynoscion analis Jenyns were collected from Chorrillos fishmarket, Lima, Perú, between January and February 2000 and necropsied to study ectoparasite monogenean Diplectanum sp. from branchial filaments. This parasite was considered a core specie, because it parasites 2/3 hosts examined. Of the fishes collected 80 were female and 40 male. Females and males showed a standard length between 16,4-27,0 cm (mean = 21,08 ± 2,24) and 16,5-26,3 cm (mean = 20,47 ± 2,06), respectively. The prevalence of infection of Diplectanurn was 72,5%, mean intensity and abundance were 3,16 ± 2,84 and 2,29 ± 2,80 respectively. This monogenean showed an overclispersal spatial distribution (2,55) at level of fish hosts. We observed a correlation between mean intensity of infestation and standard length of C. analis. Males (4,14 ± 3,75) showed a higher mean intensity than females (2,67 ± 2,14). A high prevalence, intensity and abundance of Diplectanum to 11 gill was found. However, we did not find neither preference when we separated each gill in three parts (fore, middle and hind respectively). Finally, we compared our results of population assemblages of other ectoparasite monogeneans in marine fishes. Diplectanurn sp. is a new record to C. analis and to Peru. more...

Introduction: Group A Beta-Hemolytic Streptococcus (GABHS) is the most important and common bacterial cause of acute pharyngitis in children. Nowadays, cases of resistance to antibiotics have been reported due to unnecessary and extensive usage of antibiotics. The aim of this study was to determine the prevalence of healthy pharyngeal carriers and evaluate the antibiotic susceptibility of GABHS. Materials and Methods: In this study among guidance school students of Zahedan aged 12 to 14 years, 1092 cases were selected randomly. After culturing the pharyngeal samples, GABHS was isolated and its susceptibility to different antibiotics was examined. Results were statistically analyzed by Chi-square and Exact fisher tests. Result: 76 specimens of GABHS were isolated from 1092 cultivated specimens and the differences in the prevalence of GABHS between different age groups of two sexes and different age groups of each sex were not statistically significant. The antibiotic susceptibility ratios were 98.68% for cephalexin and cefazolin, 97.37% for erythromycin and 92.11% for penicillin and the difference was not statistically significant. The susceptibility to amoxicillin was 80.26%, which was significantly different from susceptibility to cephalexin and cefazolin (p more...

Se evaluó el efecto biocida de cuatro plantas: culantro Coriandrum sativum L. (Apiaceae), tara Caesalpinia spinosa (Mol.) Kuntze (Fabaceae), amor seco Bidens pilosa L. (Asteraceae) y saúco Sambucus peruviana HBK (Caprifoliaceae) sobre adultos de Sitophilus zeamais Motschulsky 1885 (Curculionidae) y Stegobium paniceum (Linnaeus 1761) (Anobiidae) en bioensayos de mortandad bajo condiciones de laboratorio. A las máximas concentraciones empleadas (20 % p/v), los extractos acuosos de C. sativum, C. spinosa, B. pilosa y S. peruviana no mostraron efectos significativos en comparación con el control sobre ambas especies de gorgojos. Sólo los polvos secos de C. sativum produjeron un 25 % de mortandad en S. zeamais, y en cambio, C. sativum ocasionó sobre S. paniceum, un 15 % de mortandad, a las más altas dosis ensayadas (1,6 g ·10 g de maíz-1). En adición, al evaluar C. spinosa, bajo infusión acuosa (20 % p/v) sobre S. zeamais se produjo un 17,5 % de mortandad. Sin embargo, ninguna de las cuatro plantas bajo todas las formulaciones evaluadas obtuvo más de 40 % de mortandad en las dos especies de gorgojos en comparación con el control. Se analizan las posibilidades de integración de las plantas biocidas en el control de gorgojos plagas de productos agrícolas almacenadosThe biocide effect of four plants: coriander (Coriandrum sativum L. [Apiaceae]), sping holdback (Caesalpinia spinosa (Mol.) Kuntze [Fabaceae]), hairy beggarticks (Bidens pilosa L. [Asteraceae]) and elderberry (Sambucus peruviana HBK [Caprifoliaceae]), on adults of Sitophilus zeamais Motschulsky 1855 (Curculionidae) and Stegobium paniceum (Linnaeus 1761) (Anobiidae) in mortality bioassays at laboratory conditions were evaluated. At the highest concentrations of watery extracts (20 % w/v) used to C. sativum, C. spinosa, B. pilosa and S. peruviana did not show significant effects in comparison to control on both species of weevils. Only dry dusts of C. sativum showed 25 % of mortality of S. zeamais and however C. spinosa produced 15 % of mortality of S. paniceum at the higher concentrations assayed (1.6 g ·10 g of corn-1). In addition, when C. spinosa, was evaluated in infusion watery (20 % w/v) on S. zeamais, 17.5 % of mortality was found. However, none of the plants in all formulations employed had more than 40 % mortality on two species of weevils in comparison to control. The possibilities of integration of biocide plants in control of agricultural stored product pests are analyzed more...

We studied numerically external field induced memory effects in randomly perturbed nematic liquid crystals. Random anisotropy nematic-type lattice model was used. The impurities imposing orientational disorder were randomly spatially distributed with the concentration p below the percolation threshold. Simulations were carried for finite temperatures, where we varied p, interaction strength between LC molecules, and impurities and external field B. In the {B,T} plane we determined lines separating short range—quasi long range and quasi long range—long range order. Furthermore, crossover regime separating external field and random field dominated regime was estimated. We calculated remanent nematic ordering in samples at B=0 as a function of the previously experienced external field strength B. more...

We propose a highly oriented photochromic dye film for an ultraviolet (UV)-sensing layer, where spirooxazine (SO) derivatives are aligned with the liquid crystalline UV-curable reactive mesogens (RM) using a guest-host effect. For effective electrical UV sensing with a simple metal-insulator-metal structure, our results show that the UV-induced switchable dipole moment amount of the SO derivatives is high; however, their tilting orientation should be controlled. Compared to the dielectric layer with the nearly planar SO dye orientation, the photochromic dielectric layer with the moderately tilted dye orientation shows more than seven times higher the UV-induced capacitance variation. more...

Background: The aim of this review is to compare the clinical outcomes of different soft tissue grafting materials (connective tissue graft (CTG), platelet-rich fibrin (L-PRF), allogenic and xenogenic substitutes) applied in immediate implant placement with each other., Methods: Through an electronic search regarding the study's main question ("In patients with non-restorable teeth, who receive immediate dental implants (P), what is the best adjunctive soft tissue grafting approach among different autogenous, allogenous, and xenogenous grafts (I), to achieve the desired hard and soft tissue structure (O), compared to sites without grafting (C)?") in PubMed, Scopus, and ISI Web of Science, randomized controlled clinical trials (RCTs) using different soft tissue grafts were identified and analyzed using a Bayesian random-effect network meta-analysis framework. The pink esthetic score (PES), marginal interproximal bone level changes (MIBL), buccal bone thickness changes (BBT), keratinized tissue width changes (KTW), soft tissue thickness changes (STT), papilla height changes (PH), midfacial gingival margin level changes (MGML) were defined as desired outcomes of the study; except for the MIBL with 12 - 24 months of follow-up, 6 - 12 months is considered for other outcomes., Results: After duplication removal, 903 studies were identified through the electronic search; from which 21 RCTs were included in the review. Among all comparisons in different outcomes, only CTG demonstrated a significantly higher gain in STT compared to not placing soft tissue graft. However, CTG in MIBL, KTW, STT, PH, and MGML, and uni-layer xenogenic collagen matrix in PES were the superior treatments, according to the treatment ranking based on surface under cumulative ranking (SUCRA)., Conclusions: At the time of immediate implantation, there is no significant difference between different soft tissue grafts regarding the clinical outcomes of implants. However, the utilization of CTG can be suggested in cases with thin soft tissue. The acceptable efficacy of allogenic and xenogenic materials and the non-significant difference between them and CTG indicate supporting evidence for the application of these materials to specific clinical situations simultaneously with immediate implantation., Systematic Review Registration: CRD42024568586., Competing Interests: Declarations. Ethics approval and consent to participate: Not applicable. Consent for publication: Not applicable. Competing interests: The authors declare no competing interests., (© 2025. The Author(s).) more...

Statement of Problem: Whether placing implants to replace each missing tooth or using implant-supported fixed partial dentures provides better outcomes is unclear., Purpose: The purpose of this systematic review and meta-analysis was to assess the success and survival rates of implants supporting single-unit and multiunit fixed prostheses by using conventional protocols for placement and loading in short- and long-term follow-ups., Material and Methods: An electronic search was conducted in PubMed, Scopus, and Web of Science for studies published up to March 17, 2022. Comparative studies that reported the success or survival rates of both single-unit and splinted multiunit prostheses were considered for qualitative and quantitative analyses., Results: A total of 68 publications comprising 11 271 implants were included. Compared with the single prostheses, the splinted multiunit group showed no significant differences in implant success rates in the short-term (risk difference=-0.004; 95% confidence interval (CI)=-0.033 to 0.025; P=.780) and long-term (risk difference=0.003; 95% confidence interval (CI)=-0.029 to 0.034; P=.874) follow-ups. Significant statistical differences were also not found in terms of the survival rates of the 2 groups (short-term risk difference=-0.004; 95% CI=-0.031 to 0.023; P=.779, long-term risk difference=-0.002; 95% CI=-0.029 to 0.025; P=.887)., Conclusions: Implants supporting single-unit or splinted multiunit prostheses seem to be a predictable treatment in terms of survival and success over short and long periods. Nonetheless, it seems that cantilever and nonsplinted multiunit prostheses should be used with more caution., (Copyright © 2023 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.) more...

Objectives: Peri-implantitis (PI) is the most common biological issue surrounding dental implants. According to current knowledge, the aforementioned complication is not equally distributed across different populations, and gene polymorphisms might be one contributing factor. The current study aimed to examine the association between gene polymorphisms of matrix metalloproteinase- (MMP-) 1, -2, -3, -7, and -13 with PI in an Iranian demographic., Material and Methods: The study's sample included 50 subjects suffering from PI and 89 healthy controls. From each participant, a venous blood sample of 5 cc was obtained, and DNA was extracted. Gene polymorphisms were investigated using restriction fragment length polymorphism polymerase chain reaction (RFLP-PCR) combined with electrophoresis. Statistical analyses were done using the Pearson chi-square test, odds ratio, and t-test via SPSS version 28., Results: The MMP-3 (-1171 5A/6A) and MMP-7 (-181 A/G) gene polymorphisms were significantly different between the patients with PI and healthy controls (PV < 0.001 and =0.025, respectively). MMP-1 (-1607 1G/2G), MMP-2 (-1306 C/T), and MMP-13 (-77 A/G) gene polymorphisms did not, however, differ in terms of prevalence between the two groups (PV > 0.05). Moreover, the presence of the 6 A allele in the MMP-3 (-1171 5A/6A) genotype resulted in a significant decrease in PI risk (PV < 0.001)., Conclusions: Gene polymorphisms in the genotypes of MMP-3 (-1171 5A/6A) and MMP-7 (-181 A/G) were differential when comparing PI patients and healthy controls of the studied population., (© 2024 The Author(s). Clinical and Experimental Dental Research published by John Wiley & Sons Ltd.) more...

Objectives: To assess the differences between adjunctive therapy with Concentrated Growth Factor (CGF), Platelet-rich Fibrin (PRF) membranes, and available control groups in the clinical outcomes of root coverage., Materials and Methods: Randomized controlled clinical trials (RCTs) were identified in Pubmed/Medline, Scopus, and ISI Web of Science databases to assess the treatments after 6 months using a Bayesian random-effect network meta-analysis (NMA) framework regarding reduction in pocket depth (PD), clinical attachment loss (CAL), recession depth (RD), and width (RW), as well as, keratinized tissue width (KTW) and thickness (KTT) gain, and complete (CRC) and mean (MRC) root coverage percentages., Results: Thirty-two RCTs were included, from which 27, 18, 12, eight, one, and one studies investigated PRF, connective tissue graft (CTG), flap alone, CGF, enamel matrix derivative (EMD), and dehydrated amniotic membrane, respectively. Thirty studies comprising CTG and flap-alone arms other than CGF and PRF were added to NMA. No significant difference has been found between CGF and PRF; however, CGF have a higher probability of being a better treatment than PRF in PD, CAL, and RW reduction and KTW gain, and PRF has a higher probability for being better in MRC, CRC, KTT gain, and RD reduction. PRF was significantly superior to flap-alone in terms of KTT gain and RD reduction. CGF had the highest probability of being the best treatment in PD and RW reduction, but in other outcomes, CTG was superior. PRF was significantly superior to flap-alone in terms of KTT gain and RD reduction., Conclusions: Both adjunctive CGF and PRF demonstrated improvements regarding root coverage outcomes. Although there is no significant difference between PRF and CGF, these two membranes might have different impacts on different outcomes. Further studies are required for a more comprehensive conclusion, especially on CGF., Clinical Relevance: CTG is recommended for achieving ideal results in root coverage procedure. Since PRF and CGF both have a higher probability for being superior to flap alone, both could be suggested in cases which less than ideal outcomes are acceptable and minimization of patient discomfort is necessary., Competing Interests: Declarations. Ethical approval: Not applicable. Informed consent: Not applicable. Conflict of interest: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.) more...

Objective: This systematic review aims to evaluate existing evidence to investigate the therapeutic efficacy of M2 macrophage-derived exosomes in bone regeneration., Design: A comprehensive search between 2020 and 2024 across PubMed, Web of Science, and Scopus was conducted using a defined search strategy to identify relevant studies regarding the following question: "What is the impact of M2 macrophage-derived exosomes on bone regeneration?". Controlled in vitro and in vivo studies were included in this study. The SYRCLE tool was used to evaluate the risk of bias in the included animal studies., Results: This review included 20 studies published. Seven studies were selected for only in vitro analysis, whereas 13 studies underwent both in vitro and in vivo analyses. The in vivo studies employed animal models, including 163 C57BL6 mice and 73 Sprague-Dawley rats. Exosomes derived from M2 macrophages were discovered to be efficacious in promoting bone regeneration and vascularization in animal models of bone defects. These effects were primarily confirmed through morphological and histological assessments. This remarkable outcome is attributed to the regulation of multiple signaling pathways, as evidenced by the findings of 11 studies investigating the involvement of miRNAs in this intricate process. In addition, in vitro studies observed positive effects on cell proliferation, migration, osteogenesis, and angiogenesis. Heterogeneity in study methods hinders direct comparison of results across studies., Conclusion: M2 macrophage-derived exosomes demonstrate remarkable potential for promoting bone regeneration. Further research optimizing their application and elucidating the underlying mechanisms can pave the way for clinical translation., Competing Interests: Declaration of Competing Interest The authors declare no conflict of interests regarding this study., (Copyright © 2024 Elsevier Ltd. All rights reserved.) more...

This systematic review and meta-analysis assesses the clinical outcomes of implants inserted during or following transcrestal sinus lifts. The study protocol was prospectively registered on PROSPERO (CRD42024504513). PubMed, Web of Science, Embase, and Scopus databases were searched up to 21 February 2024, and randomised clinical trials utilising transcrestal sinus lifts were included. Qualitative and quantitative syntheses were conducted. A random effects model was used to pool the survival rate of implants placed with transcrestal sinus lifts using hand osteotomes without grafting, along with meta-regression and subgroup analyses. Funnel plots and Egger's linear regression were used to explore possible publication bias. Probabilities of less than 0.05 were considered significant. A total of 1807 records were identified after the initial search. Seventeen studies were included with 10 of them considered for meta-analysis. Studies used hand osteotomes, a combination of piezoelectric and hand osteotomes, drills, and smart lifts for sinus elevation. Only studies that used hand osteotomes reported subsequent vertigo and dizziness in patients. The meta-analysis showed a 100% (95% CI: 99% to 100%) survival rate for both grafted and non-grafted transcrestal sinus lifts using hand osteotomes. Meta-regression showed that follow-up time did not significantly affect the implants' survival. Subgroup analyses showed no significant difference between bone-level and tissue-level implants and one-stage or two-stage implants. On considering the limitations of this study it can be concluded that closed maxillary sinus elevation can be considered a relatively safe technique that is associated with a high survival rate. However, caution should be taken when using hand osteotomes because of a higher rate of sinus lining perforation and reported patient vertigo., (Copyright © 2024 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.) more...

This study aimed to design a new surgical guide for controlling the mesiodistal distance between implant osteotomies and adjacent teeth as well as the osteotomy depth in partially edentulous patients. The guide kit was designed with design software and milled with a CNC (computer numerical control) router. The guide consisted of 2 components-stoppers and crown guides-for determining the drilling depth and mesiodistal position, respectively. The stoppers were designed in 7.5-, 9.5-, and 11.5-mm lengths, and the crown guides were fabricated with outer diameters of 5.0, 6.0, 7.0, and 8.0 mm. The accuracy of the guide was assessed by preparing a total of 20 implant osteotomies in 4 partially edentulous models and comparing the dimensions of the actual osteotomies to the values that were predicted to occur with the use of the surgical guides. Osteotomies were prepared using the 7.5-mm stopper with either the 7.0- or 8.0-mm crown guide. Cone beam computed tomography (CBCT) was used to obtain images for analysis of osteotomy-tooth mesiodistal distances, which were predicted to be 3.0 or 5.5 mm, depending on position; interosteotomy mesiodistal distances, which were predicted to be 3.0 mm; and osteotomy depth, which was predicted to be 11.5 mm. A 1-sample t test was used to determine if there were significant differences between the predicted values and the measurements of the guided osteotomies on the CBCT images of the mandibular models, and an independent t test was conducted to compare the results of 3.0- and 5.5-mm osteotomy-tooth distances (α = 0.05). Differences between the predicted and actual values of the interosteotomy mesiodistal distance (P = 0.516) and osteotomy depth (P = 0.847) were not statistically significant. The actual osteotomy-tooth mesiodistal distances were significantly different from the predicted values of 3.0 (P = 0.000) and 5.5 mm (P = 0.001), with higher mean differences of 0.46 and 0.60 mm, respectively. The designed guide had a high accuracy in achieving optimal linear interosteotomy mesiodistal distances and osteotomy depths, and the obtained mean values were clinically acceptable., Competing Interests: No conflicts of interest reported. more...

The occurrence of desquamation, shedding and erythema on marginal and attached gingiva is described as desquamative gingivitis (DG). Various autoimmune/dermatological disorders cause DG.The aim of the present systematic review was to gather information on all possible kinds of treatment for DG, based on specific DG diagnoses.The review was organized following the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) protocol. An electronic search was conducted in the PubMed, Scopus and Google Scholar databases, up to April 2022. Reviews, letters and studies with less than 2 participants were excluded.Fifteen publications matched the eligibility criteria: 6 case series; 5 clinical trials; 3 randomized clinical trials (RCTs), and 1 cohort study. A total of 330 patients were enrolled, mostly women (81.52%), with an average age of 57.6 years. Diagnostic characteristics corresponded to oral lichen planus (OLP) (n = 249), mucous membrane pemphigoid (MMP) (n = 30), pemphigus vulgaris (PV) (n = 19), plasma cell gingivitis (PCG) (n = 4), erythema multiforme (EM) (n = 1), and non-specified diseases (NSD) (n = 27). Oral lichen planus and MMP were eliminated using oral hygiene instructions with topical clobetasol and/or doxycycline monohydrate. Pemphigus vulgaris, PCG and EM were treated with topical clobetasol.To conclude, each DG case requires personalized treatment, depending on the diagnosis. more...

Methods: Patients examined during postloading maintenance visits were included in this study. The presence of peri-implant mucositis, peri-implantitis and several patient- and implant-related independent variables was recorded. Statistical analysis was performed using the logistic regression analysis. The odds ratios (OR) of the potential association between each variable and the occurrence of peri-implant diseases were evaluated., Results: Among the 114 participants with 403 implants, peri-implantitis was found in at least one implant of nine individuals (7.89%), and a total of 13 implants were affected by peri-implantitis (3.22%). The univariate regression analysis revealed a statistically significant association between arch (OR = 4.81; 95% CI = 1.27-31.36) and soft tissue thickness (OR = 4.07; 95% CI = 1.33-13.73) with the occurrence of peri-implantitis. The multivariate analysis confirmed the significant impact of soft tissue thickness (OR = 3.60; 95% CI = 1.16-12.24)., Conclusion: The occurrence of peri-implant diseases can be influenced by various factors. However, in order to accurately identify risk indicators, it is necessary to conduct long-term prospective studies., Competing Interests: The authors declare that they have no conflicts of interest., (Copyright © 2024 Mahdi Kadkhodazadeh et al.) more...

The present study aims to evaluate the trends of oral implant-related research in design and topics between the range of 2016 to the end of 2022. The electronic search was conducted in MEDLINE via Pubmed. Papers published in Clinical Oral Implant Research, Clinical Implant Dentistry and Related Research, and International Journal of Oral Implantology as well as previously European Journal of Oral Implantology, International Journal of Oral and Maxillofacial Implants, and Journal of Oral Implantology between January 1, 2016, and December 30, 2022, were retrieved. Articles were classified according to their study design and major subjects. The Joinpoint regression model was used to determine changes in the trends of study designs and topics. Statistical significance was defined as a p-value <.05. A total of 3382 articles were analyzed in this study. In the specified period, in vivo, prospective cohort, retrospective case control, randomized clinical studies in the design and prosthetic complications, peri-implant hard tissue studies in the topic experienced a significant decreasing pattern in the number of published articles as well as the total number of articles. Case reports and series, retrospective cohort, nonrandomized clinical studies in the design and outcomes of implant-related treatment plans, immediate implant placement, and peri-implantitis in the topic experienced a significant decreasing pattern followed by a significant increasing pattern with a turning point between 2017 and 2020. Considering the limitations of this scientific topical trend analysis, it can be concluded that the recent pandemic affected the research path in oral implantology in many ways. more...

Background: The purpose of this study was to review the literature on the efficacy of different surgical regenerative methods for peri-implantitis treatment., Methods: A preliminary search was conducted in seven electronic databases. The studies included in the analysis implemented surgical regenerative treatment in at least one study group. Baseline and follow-up values for bleeding on probing (BoP), pocket depth (PD), plaque index (PI), bone level (BL), and bone gain (BG) were extracted. The standardized mean difference (SMD) was calculated using Cohen's d or Hedges' g, and a random-effects-restricted maximum likelihood (REML) method was applied for the meta-analysis., Results: Fifteen studies were included in the qualitative synthesis. The meta-analysis was performed on six studies comparing regenerative techniques that involved bone grafts with those that did not. The overall effect size for using bone grafts at the one-year follow-up was 0.04 (95% CI: -0.26‒0.35; P =0.78) for BoP, -0.08 (95% CI: -0.42‒0.27; P =0.66) for PD, 0.37 (95% CI: 0.08‒0.65; P =0.01) for PI, -0.44 (95% CI: -0.84 to -0.03; P =0.03) for BL, and 0.16 (95% CI: -0.68‒1.01; P =0.70) for BG., Conclusion: Various materials have been employed for peri-implant defect filling and coverage. A bone substitute did not significantly improve BoP, PD, and BG values, while PI and BL were significantly ameliorated at one-year follow-up. However, recommending a single unified protocol as the most effective for surgical regenerative treatment of peri-implantitis was not feasible., Competing Interests: The authors declare that they have no competing interests., (© 2024 The Author(s).) more...

Background: The use of bone graft materials has significantly increased. Given the inherent variations in structure and functionality between different grafting materials, this evaluated and compared the physical attributes of antler and bovine femur bone substitutes., Methods: In the present in vitro investigation, the surface morphological architecture of the two bone substitutes with different origins was assessed through scanning electron microscopy. Furthermore, the Brunauer-Emmett-Teller (BET) technique was employed to measure the porosity, specific surface area (SSA), and pore morphology., Results: Scanning electron microscopy observations indicated that the surface of the bovine particles appeared smoother, while the antler particles exhibited a rougher surface texture. The BET analysis revealed that both samples exhibited identical pore morphology. The SSA was 15.974 m 2 /g in the antler particles compared with 18.404 m 2 /g in the bovine sample. The total porosity volume in the antler and bovine femur bone substitutes were 0.2172 cm 3 /g and 0.2918 cm 3 /g, respectively. Additionally, the antler particles had a porosity percentage of 40%, whereas the bovine femur bone substitute showed a porosity percentage of 43.5%., Conclusion: Based on the results of this study, it seems that the two samples of bone grafting materials have comparable physical structures., Competing Interests: The authors do not have any financial interest in the companies whose materials were included in this study., (© 2024 The Author(s).) more...

In addition to the proper selection of techniques, appropriate treatment sequencing and prioritization are prerequisites for successful periodontal and implant procedures. The aim of this study was to provide evidence-based time frames for various procedures pertaining to periodontal and implant treatment. A literature review was conducted to collect data on tissue healing; in areas in which data were lacking, the viewpoints of experienced clinicians were solicited to establish a consensus. This review reports recommended time frames for the healing processes associated with surgical crown-lengthening procedures (both functional and esthetic), fresh socket management, alveolar ridge management, soft tissue management, sinus floor augmentation, implant loading, and peri-implant defect management., Competing Interests: No conflicts of interest reported. more...

Background: Different methods have been proposed to investigate the fixation stability of dental implants, each of which has its limitations. Among these methods, resonance frequency analysis (RFA) has been widely utilized to measure dental implant stability. This study aimed to assess dental implants with two non-destructive RFA and acoustic modal analysis (AMA) validated with a finite element simulation of the fundamental natural frequency (NF) of the bone analog-implant structure., Material and Methods: A total number of 18 implants were inserted into two Polyurethane (PU) bone blocks with different densities (0.16 g/cc and 0.32 g/cc). AMA was used to measure NF; First, the sound originating from the axial tapping of the implant was recorded with a simple microphone. Secondly, a fast Fourier transformation algorithm was conducted to determine the NF of the implant-bone analog structure. In parallel, the ISQ (Implant Stability Quotient) value was measured using the Osstell® device. Finally, using finite element analysis (FEA), the implant-bone analog structure was modeled for validation., Results: Doubling the bone analog density resulted in an average increase of 82% and 47% in the NF and ISQ using AMA and Osstell®, respectively (P-value<0.05). Furthermore, a strong linear relationship (R2= 0.93) was observed between the measured NF and ISQ values in the linear regression analysis. The NF of the dental implant predicted by FEA was overestimated by about 15.2% and 15.0% than those in the low- and high-density PUs, respectively. Moreover, the FEA predicted an increase of 83% in NF by increasing the bone analog density from 0.16 to 0.32 g/cc., Conclusions: Having required the minimum process combined with easily available equipment makes it an ideal method for fixation strength studies. The good correspondence between the ISQ values and NFs, in addition to the good accuracy and reliability of the later method, confirms its application for fixation stability assessment. more...

Objective: The purpose of this study was to assess the feasibility of phenotype modification in orthodontic patients using combined bone and soft tissue grafting substitutes., Clinical Consideration: The surgical procedure was conducted on 18 patients (3 males, 15 females). Periodontal phenotype modification was conducted using demineralized freeze-dried bone allograft and a xenogeneic collagen matrix. The following parameters were recorded for each tooth at baseline and 12-month follow-up: O'Leary plaque index (PI), probing depth (PD), bleeding on probing (BOP), gingival thickness (GT), keratinized tissue width (KTW), gingival recession (GR), and vestibular depth (VD). The results showed a statistically significant increase in GT (2.02 ± 0.39 mm), KTW (1.11 ± 0.82 mm), and VD (0.18 ± 1.16 mm) (p < 0.05). GR was also significantly decreased (1.02 ± 0.99 mm) (p < 0.05)., Conclusion: Within the limitation of this study, the proposed approach enhanced the periodontal condition in orthodontic patients. However, further studies with a larger sample size are needed to ensure long-term stability., Clinical Significance: Hard and soft tissue conditions have paramount importance for long-term periodontal stability. Phenotype modification in orthodontic patients can diminish the probability of adverse consequences and result in optimal esthetic outcomes. The proposed technique using combined bone and soft tissue substitutes indicated promising results and could be recommended in orthodontic patients with thin periodontal phenotypes., (© 2023 Wiley Periodicals LLC.) more...

Background: Xenograft bone substitutes can be obtained from different animals and processed using various methods. The present in vivo study evaluated bone regeneration after using three types of xenografts with different sources in critical-sized bone defects in rabbit calvaria., Methods: Four 8-mm defects were created in calvaria of 14 New Zealand and white male rabbits. Three out of four defects were filled with xenografts of bovine, camel, and ostrich sources. The fourth defect was left unfilled as the control group. Seven rabbits were sacrificed after eight weeks and seven others after 12 weeks. Micro-CT imaging and histologic evaluation were further performed on dissected calvarias., Results: After 8 and 12 weeks, the highest and lowest percentages of new bone formation were observed in the camel (27.71% and 41.92%) and control (11.33% and 15.96%) groups, respectively. In the case of residual material, the ostrich group had the most value after eight weeks (53%), while after 12 weeks, it was highest in the camel group (37%). Micro-CT findings were consistent with histologic results., Conclusion: Although all three xenografts can be good choices for treating bone defects, camel-sourced xenograft seemed to be better than the other two groups. The origin and processing procedures of xenografts affected their final characteristics, which should be considered for clinical use., Competing Interests: The authors declare no competing interests., (© 2024 The Author(s).) more...

Background: The novel two-stage technique presented in this study is based on guided bone regeneration for three-dimensional bone augmentation., Methods and Results: The proposed technique was performed to augment an atrophic alveolar ridge in the maxilla and mandible. This method is based on using an autogenous bone plate, a mixture of allogeneic bone graft and injectable -platelet-rich fibrin, and a bioresorbable barrier membrane. Based on the cases presented in this study, sufficient osseous regeneration was achieved to place dental implants in an ideal position., Conclusion: Within the limitations of the present study, it seems that in situ shell technique could be a beneficial method to augment the extremely atrophied ridges with less morbidity and shorter operative time., Key Points: Why is this case new information? The cases presented a new technique using in situ autogenous plates for ridge augmentation. What are the keys to the successful management of this case? The keys to the successful management of these cases are proper flap management and less traumatic bony plate preparation. What are the primary limitations to success in this case? The primary limitation to success in this technique would be a need for high surgical skills to conduct the procedure accurately., (© 2023 American Academy of Periodontology.) more...

Objective: The occurrence of peri-implant soft tissue dehiscence, especially in the esthetic zone, can be challenging. This study sought to investigate how the passage of time affects the outcomes of treatment for peri-implant soft tissue dehiscence coverage., Materials and Methods: A literature search was performed up to April 2023 via PubMed, Scopus, and Web of Science to retrieve studies reporting the data on peri-implant soft tissue dehiscence of at least 2-time points (baseline and follow-up). Clinical trials with a minimum of 5 participants, reporting at least 1 primary outcome, and with a minimum follow-up of 3 months were included. The primary outcomes were the changes in dehiscence depth, complete coverage, and mean coverage at different time points., Results: Seven studies with 112 participants and 119 implants were included. Dehiscence depth increased insignificantly between 3 to 6 months. Although the dehiscence depth increased from 6 to 12 months in the tunnel group, it decreased in the coronally advanced group, and a slight decrease was observed from 12 to 72 months. Soft tissue thickness was the predictor for soft tissue margin stability. However, no significant relationship was found between the baseline dehiscence depth and complete coverage., Conclusions: Within the limitations of this study, it seems prudent to wait at least 6 months to achieve a stable soft tissue margin., Clinical Significance: The occurrence of peri-implant soft tissue dehiscence, especially in the esthetic zone, can be a challenging complication. It is important not only to achieve coverage but also to ensure that the treatment results remain stable in the long term, in order to satisfy both patients and clinicians. A reasonable approach would be to wait for at least 6 months to achieve a stable soft tissue margin., (© 2023 Wiley Periodicals LLC.) more...

Many patients require edentulous ridge augmentation for dental implant placement. The main objective of this study was to evaluate the results of maxillary edentulous ridge augmentation exclusively with xenograft materials with and without simultaneous sinus floor elevation. This study reports the data retrieved from the records of 16 patients. The treatment outcome was assessed at least 6 months, postoperatively. Paired samples t -test or Wilcoxon Signed Rank test was used to compare the pre-and postoperative ridge dimensions. Dental implants were placed simultaneously in 7 patients, while 9 patients underwent delayed implant placement. In total, 68 implants were placed, and 12 patients also underwent maxillary sinus floor augmentation. A significant bone gain was achieved in both horizontal and vertical dimensions of edentulous maxillary ridges ( P  < 0.001). Ridge width increased by an average of 4.35 ± 1.90 mm (95% CI: 3.84 to 4.85 mm) while ridge height in areas of sinus floor augmentation increased by 8.19 ± 2.91 mm (95% CI: 7.33 to 9.05 mm). Within the study limitations, it appears that maxillary ridge augmentation according to the guided bone regeneration (GBR) protocols with exclusive use of xenograft particulate materials can provide optimal bone quantity for dental implant placement., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 THE AUTHORS.) more...

This study aimed to compare the volume and quality of the newly formed bone following application of two types of xenografts and one synthetic material in bone defects in rabbit calvaria from histological and micro-CT aspects. Four 8-mm defects were created in 12 rabbit calvaria. Three defects were filled with bone substitutes and one was left unfilled as the control group. The newly formed bone was evaluated histologically and also by micro-CT at 8 and 12 weeks after the intervention. The percentage of osteogenesis was comparable in histomor-phometric assessment and micro-CT. Histological analysis showed that the percentage of the newly formed bone was 10.92 ± 5.17%, 14.70 ± 11.02%, 11.47 ± 7.04%, and 9.45 ± 5.18% in groups bovine 1, bovine 2, synthetic, and negative control, respectively after 8 weeks. These values were 33.70 ± 11.48%, 26.30 ± 18.05%, 22.92 ± 6.30%, and 14.82 ± 8.59%, respectively at 12 weeks. The difference in the percentage of the new bone formation at 8 and 12 weeks was not significant in any group (P > 0.05) except for bovine 1 group (P < 0.05). Micro-CT confirmed new bone formation in all groups but according to the micro-CT results, the difference between the control and other groups was significant in this respect (P < 0.05). All bone substitutes enhanced new bone formation compared with the control group. Micro-CT assessment yielded more accurate and different results compared with histological assessment. more...

Dental implants are currently the preferred choice to restore function and esthetics. Nonetheless, explantation is sometimes inevitable in cases with advanced bone loss, implant fracture, or improper implant position. This study aimed to propose an algorithm for reimplantation at sites of previous failure. There is limited evidence on the replacement of failed implants, most of which are case reports or clinical trials with a small number of patients. To the best of the authors' knowledge, this is the first study proposing a clinical-decision algorithm to help clinicians manage implant failures with new implants. There are a variety of reasons contributing to implant failure: The etiologic factor of failure and the morphology of the residual defect have paramount importance on implant removal techniques and subsequent treatment modalities. There is no consensus on a distinct protocol to replace failed implants. However, the clinicians and patients should know that placing a new implant in an area with a history of failure, regardless of early or late implant failure, may have a lower survival rate. more...

Statement of Problem: Immediate implant placement provides a popular therapeutic option. However, compromised sockets may jeopardize the treatment outcome., Purpose: The purpose of this systematic review and meta-analysis was to investigate the treatment outcome in terms of the implant survival rate and success parameters of immediate implant placement in compromised extraction sockets., Material and Methods: An electronic search was conducted in PubMed, Embase, Cochrane Library, and ISI Web of Science up to January 2021. Studies evaluating implant survival rate and main success parameters were included for a qualitative and quantitative analysis (risk ratio and mean difference)., Results: In total, 43 studies with analysis of 4825 sockets were included. Compared with the noncompromised sockets, the compromised group showed no significant differences in implant survival rates (risk ratio=0.992; 95% confidence interval (CI)=0.979 to 1.005; P=.246). No significant statistical differences were found in marginal bone level at ≤12 months (mean difference [MD]=0.033; 95% CI=-0.012 to 0.078; P=.154) or esthetic parameters., Conclusions: Immediate implant placement in compromised sites does not appear to decrease the survival and success rates. However, randomized clinical trials with large sample sizes should be conducted to draw a definite conclusion about the efficacy and safety of this treatment protocol in compromised sockets., (Copyright © 2021 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.) more...

Background: Xenograft and allograft bone substitutes are widely used to replace the missing bone in defects. Since removing the packaging of these grafts can nullify their sterilization, this study aimed to evaluate the sterility and bioactivity changes of an allograft and a xenograft following uncapping/recap., Methods: Two types of commercial allograft and xenograft vials were unpacked and further exposed to operating room air, where implant surgery was performed for one second, ten minutes, and one hour. After three repetitions, samples were analyzed using microbiological tests and scanning electron microscopy (SEM) with energy dispersive x-ray analysis (EDX) for sterility and bioactivity evaluation., Results: None of the bone graft samples showed microbial growth or bioactivity-negative changes after seven days of unpacking the vials., Conclusion: Despite the positive results of this study, future studies and more analysis considering influential factors are required. Also, disinfection and air exchange must still be observed during biomaterial application and bone grafting procedures., Competing Interests: The authors declare that they have no competing interests., (© 2023 The Author(s).) more...

Considering the widespread use of dental implants, a precise definition for peri-implant tissue health and an appropriate classification for peri-implant diseases are imperative for researchers and dental clinicians. However, absence of a unanimous definition and an efficient classification system has created controversies in the published reports regarding the epidemiology and prevalence of peri-implant diseases. Moreover, lack of a standard system for differentiation of different grades of peri-implantitis further complicates the interpretation of reports regarding the diagnosis prevalence, treatment, and outcome of such conditions, and highlights the need for a classification system based on the severity of disease. Almost all of the currently available classification systems focus on the assessment of health or disease status of the tissues around loaded implants. The purpose of the present study is to propose a classification/scoring system for peri-implant tissue health before and after prosthetic loading. This grading system can aid the researchers and dental clinicians in assessment of peri-implant tissue condition both before and after prosthetic loading of dental implants. more...

Objective: This study sought to compare the thickness of hard and soft tissues between edentulous and contralateral tooth sites., Materials and Methods: This split-mouth study evaluated 153 partially edentulous patients. The measurements were made on cone-beam computed tomography (CBCT) scans. The soft tissue thickness was measured at the cementoenamel junctional (CEJ) level, and at 2, 4, and 6 mm apical to the CEJ in the facial and palatal aspects. The bone thickness of the opposite quadrant was also recorded at 2, 4, and 6 mm apical to the CEJ. The Mann-Whitney U test and the Spearman's rank correlation coefficient were applied for further statistical analyses., Results: At the edentulous sites, significant soft tissue loss was noted at the CEJ level ( p  < 0.0001) and a considerable gain was noted at 2, 4, and 6 mm apical to the CEJ ( p  = 0.004, p  < 0.0001, p  ≤ 0.0001, respectively). A significant hard tissue loss was noted at 2 mm apical to the CEJ but a significant hard tissue gain was observed at the edentulous sites ( p  < 0.0001). The soft tissue gain at 6 mm apical to the CEJ was significantly associated with an increase in buccolingual diameter ( p  = 0.004) while the hard tissue loss at 2 mm apical to the CEJ was significantly correlated with a reduction in buccolingual diameter ( p  = 0.020)., Conclusion: Different amounts of tissue thickness alterations occurred in different levels of socket., Competing Interests: Conflict of interestThe authors declare that they have no conflict of interest to this study., (© The Association of Oral and Maxillofacial Surgeons of India 2021.) more...

Introduction: This study aimed to assess the quantity and quality of available bone to provide the autologous bone graft from mandibular ramus., Material and Methods: CBCT scans were collected and mandibular ramus was evaluated by measuring a variety of parameters including volume, bone height, cortical, and cancellous bone thickness. Data analysis was performed using descriptive statistics and inferential statistics. We used the Kolmogorov-Smirnov test for the evaluation of data normality. We then applied Pearson correlation and independent t -test for normal variables, and Spearman and Mann-Whitney correlation tests for abnormal variables. Statistical analysis was performed using SPSS version 19 and P value < 0.05 was considered significant., Results: A total of 52 women and 32 men (aged 21 to 70) were included in this study. The mean bone volume was 2.7 ± 0.70 cm 3 [95%confidence interval (CI) 1.3-4.5]. The mean bone density in the middle section was 1016.36 ± 231.58 Gy value (95% CI 475.6-1520.9). Kolmogorov-Smirnov test revealed that the variables such as apical cortical/cancellous ratio ( P  = 0.005), middle-cancellous bone thickness ( P = 0.016), and middle cortical/cancellous ratio ( P  = 0.005) were abnormal and the rest were normal. Bone density, as well as the amount of cortical bone in the middle and apical regions, had a significant reverse correlation with age ( P  < 0.001)., Conclusion: The volume, density, and cortical/cancellous ratio are independent of sex. The reverse relationship between age and bone density, as well as the amount of cortical bone in several parts, indicates a decrease in bone quality with aging., Competing Interests: Conflict of interestThe authors declare that they have no conflict of interest., (© The Association of Oral and Maxillofacial Surgeons of India 2021.) more...

Many of the criteria commonly considered in treatment planning for severely damaged teeth are well known to clinicians. However, a systematic approach to decision-making is lacking. The purpose of this article is to introduce a quantitative systematic risk assessment scoring system (RASS) to determine the long-term prognosis for severely damaged teeth based on several important factors. Before any treatment decision is made, the dentist should take into account the role of systemic parameters such as the medical condition of the patient, smoking status, psychological factors, patient expectations with regard to the duration and overall cost of treatment, and periodontal health. In the assessment of local factors, emphasis should be placed on 5 parameters: crown to root ratio, root condition, risk of furcation involvement, complexity of the final restoration, and esthetic results. In the proposed RASS, each of these parameters is ranked using 4 color-coded levels of risk: optimal (green), favorable (blue), unfavorable (yellow), or hopeless (red). The presence of even 1 parameter in the red zone is sufficient to consider tooth extraction. If no parameter is in the red zone, the final decision should be made after the possible effects of all of the clinical conditions are weighed and the overall risk of treatment failure is determined. Clinical decision-making with regard to the preservation or extraction of severely damaged teeth is a challenging, multifactorial process. The RASS introduced in this article focuses on 5 main factors to simplify and organize the decision-making process; however, many other parameters may affect the final treatment decision. Moreover, no decision-making system can be definitively applied to all clinical scenarios, and the entire process depends on the knowledge, experience, and expertise of the clinician., Competing Interests: The authors report no conflicts of interest pertaining to any of the topics discussed in this article. more...

Decontamination of implant surfaces is important to the treatment of peri-implantitis. Er:YAG laser and air-powder abrasion system are regarded as the most effective means of decontamination of implant surfaces. The aim of this in vitro study was to compare the activity of human dental pulp stem cells (hDPSCs) cultured on decontaminated sandblasted titanium discs using Er:YAG laser irradiation and air-powder abrasion. Forty-five titanium discs were contaminated with Escherichia coli (E. coli) bacteria and fifteen titanium discs served as sterile control groups. Thirty contaminated titanium discs were decontaminated with Er:YAG laser or air-powder abrasion system and fifteen contaminated discs were used as contaminated control group. Afterwards, hDPSCs were seeded on all sixty experimental titanium discs. The effects of two decontamination tools on hDPSCs viability were evaluated by MTT assay. Alkaline phosphatase (ALP) activity assay, quantitative real-time PCR analysis and alizarin red staining method were performed to assess hDPSCs osteogenic differentiation. Scanning microscope electron (SEM) was also used to evaluate the effects of two different decontaminated methods on cellular morphology. Our study showed that decontamination using Er:YAG laser caused maximum cell viability. However, the ALP activity was not different in laser and air-abrasion groups. The significant expression of an osteoblastic marker and stronger Alizarin red staining were observed in laser irradiation groups. In addition, SEM observation indicated that grown cells were more stretched and more filopodia in Er:YAG-treated discs. In the present study, Er:YAG laser and air-powder abrasion improved the activity of the cells cultured on the decontaminated titanium discs. However, in comparison with air-powder abrasion, Er:YAG laser was more effective., (© 2022. The Author(s), under exclusive licence to Springer-Verlag London Ltd., part of Springer Nature.) more...

Aims: This study aimed to compare the biological reactions of dental pulp stem cells (DPSCs) cultured on new xenograft bone substitutes derived from camel and bovine bones., Materials and Methods: DPSCs were cultured and placed on different xenograft materials including Bone Plus (bovine), Camel Bone, and demineralized bovine bone matrix. The viability and proliferation of cells were evaluated by the methyl thiazolyl tetrazolium assay after 24, 48, and 72 h. The alkaline phosphatase (ALP) test and Alizarin red staining were performed at 7 and 21 days to assess the osteoblastic differentiation of cells. Osteocalcin (OCN) gene expression was evaluated qualitatively at 3-, 7- and 14-days using polymerase chain reaction (PCR). Semi-quantitative PCR was also performed using ImageJ software. Data were analyzed by ANOVA and Tukey's honestly significant difference test., Results: The cell proliferation rate was significantly different among the three xenograft bone substitutes at 24-, 48- and 72 h ( P < 0.05). The ALP activity of DPSCs in all three xenograft bone substitute groups was greater than that in the control group ( P < 0.05). Alizarin red staining showed no significant difference in the formation of calcified nodules among the groups. Qualitative and semi-quantitative PCR displayed that the expression of OCN gene in the Camel Bone and Bone Plus groups was higher than that in the demineralized bovine bone matrix group., Conclusions: The Camel Bone xenograft caused a high proliferation rate and optimal osteogenic differentiation of DPSCs qualitatively and semi-quantitatively in vitro . Further studies are required on this xenograft bone substitute., Competing Interests: There are no conflicts of interest., (Copyright: © 2022 Indian Society of Periodontology.) more...

Objectives: The dysbiosis of bacteria and horizontal transfer of antibiotic resistance genes (ARGs) could be highly problematic particularly in the oral environment. Here, we aimed to identify the anaerobic species from patients with periodontitis and to screen the isolates for the β-lactamase resistance genes, bla TEM , cfxA, its variants, and mobA., Methods: The 129 samples from periodontal pockets were subjected to anaerobic culture, followed by 16S rRNA gene sequencing, PCR assays for the cfxA, bla TEM , and mobA. The minimum inhibitory concentration (MIC) of amoxicillin, ampicillin, amoxicillin/clavulanate, ampicillin/sulbactam, and cefixime was determined against CfxA producing isolates using MIC Test Strips., Results: The species with frequency higher than 10% were Lactobacillus spp. (26.3%), Streptococcus spp. (18.8%), Leptotrichia wadei (14%) and Veillonella spp. (11.4%). The bla TEM was not found in any of the isolates whereas cfxA was found in 12.5% of isolates including V. parvula, V. rogosae, Prevotella nigrescens and Campylobacter concisus. Of CfxA variants, CfxA2 (90%) was the most frequent one. Among the CfxA producing isolates, the resistance to ampicillin and amoxicillin was observed only in two isolates of P. nigrescens and V. rogosae., Conclusions: This study showed that various anaerobes species may be involved in the development of periodontitis. Of them, Prevotella and Veillonella species were found to commonly carry cfxA even though they are susceptible to beta-lactams and its combination., Competing Interests: Declaration of competing interest The authors declare that they have no conflict of interest., (Copyright © 2022 Elsevier Ltd. All rights reserved.) more...

Objective: The aim of this study was to evaluate the clinical and radiographic outcomes of the "vertically expander screw" (VES) technique as a novel approach for maxillary sinus floor elevation and simultaneous implant placement., Materials and Methods: Forty-four patients (26 females, 18 males) received 71 implants with simultaneous transalveolar sinus floor elevation via the VES technique. The threaded bone expanders were used to elevate the sinus floor as well as bone expansion. The patients were followed-up on a regular basis, and final clinical and radiographic examinations were performed at least 24 months following functional loading. Statistical analysis was conducted using the Chi-square test, the correlation coefficient, and the independent t test ( p  < 0.05, 95% confidence interval)., Results: All implants showed successful osseointegration. The mean marginal bone loss (MBL; 0.38 ± 0.75 mm) at the site of premolars was not significantly different from the value at the site of molars (0.17 ± 0.50 mm). The mean intrasinus bone gain (IBG) was not significantly different (3.47 ± 1.22 mm and 4.11 ± 1.67 mm, respectively; p  = 0.92). Evaluation of implant success index (ISI) score revealed no difference between the premolars and molars ( p  = 0.12)., Conclusion: Despite the limitations of the present study, it seems that the VES technique and simultaneous implant placement in carefully selected cases may result in promising outcomes., Clinical Relevance: Insufficient alveolar bone height and poor bone quality often complicate implant placement in the edentulous posterior maxilla. The VES technique and simultaneous implant placement can bring about favorable clinical and radiographic outcomes and high survival rate in carefully selected cases., Competing Interests: Conflict of interestThe authors declare that they have no conflict of interest., (© The Association of Oral and Maxillofacial Surgeons of India 2020.) more...

Background: The maxillary palatine process (MPP) is an excellent source of autogenous bone transplants for anterior maxillary reconstruction. This research aimed to determine the quantity and quality of accessible MPP as a donor location., Methods: Cone-beam computed tomography (CBCT) scans of patients referred to the School of Dentistry were evaluated by a certified examiner. The harvestable MPP was defined as the space between the distal surfaces of maxillary first premolars. OnDemand 3D Imaging software was used to determine bone properties. SPSS software was used to investigate the following variables: Bone characteristics are correlated with age and gender, accessible volume, and palatal width and height. P <0.05 was defined as the level of statistical significance., Results: This study was performed on CBCT scans of 81 subjects (41 females and 40 males). MPP volume and palatal heights were 1.33±0.53 cm3 and 20.86±5.51 mm, respectively. Maximum bone density was observed around lateral incisors. Palatal width was 33.81±2.42 mm between canines and 41.81±2.66 mm between premolars. The MPP volume was significantly greater in males ( P <0.001). Additionally, there was a positive correlation between the volume and palatal width ( P <0.05)., Conclusion: Within the constraints of this research, there is a limited supply of MMP accessible for use as a graft source, and it is best suited for treating localized bone lesions. The favorable link between palatal breadth and harvestable volume aids the surgeon in estimating the quantity of bone accessible during the first evaluation., Competing Interests: The authors declare that they have no known competing and financial interests or personal relationships that could have influenced the work reported in this paper., (© 2022 The Author(s).) more...

Purpose: The aim of this study was to evaluate and compare the effect of changing five macrostructural design parameters of dental implants on the peak strains experienced by the interfacial bone., Materials and Methods: Five geometric variables, including three body-related (implant length, diameter, and taper) and two thread-related (thread depth and thread angle) parameters, were defined. The alveolar bone was modeled as a block with anisotropic and linearly elastic properties with 20-mm height and 12-mm buccolingual and mesiodistal dimensions. Oblique occlusal loads (100-N vertical and 20-N horizontal) were applied to the abutment surface. A total of 162 models with different designs were defined by implementation of a full-factorial design. The peak values of the compressive and tensile principal strains in the cortical and cancellous bones were calculated by finite element analysis (FEA)., Results: Implant diameter and length had maximum and minimum effects on the peak compressive and tensile strains at the cortical interface, respectively. Implant diameter and thread depth had maximum and minimum effects on the maximum compressive strain at the cancellous interface, while thread angle and length had maximum and minimum significant effects on the maximum tensile strain at the cancellous interface., Conclusion: The interaction of thread parameters and taper has the greatest effect on the peak compressive and tensile strains at the cancellous interface and also on the peak tensile strain at the cortical interface, while body-related parameters are more effective on the peak compressive strain at the cortical interface. more...

This study retrospectively evaluated the effect of soft tissue condition on peri-implant health. Clinical variables (Plaque Index, keratinized tissue width, gingival biotype, and vestibular depth) were recorded. Probing depth, soft tissue recession, bleeding on probing, and radiographic marginal bone loss were assessed in relation to independent variables. Statistical analysis was performed using Mann-Whitney U test or Kruskal-Wallis rank test and a logistic regression model at the implant level. A total of 139 implants in 43 patients were assessed. Bleeding on probing was recorded at 54.7% sites, which was significantly related to the biofilm accumulation. Gender, history of periodontal disease, patient adherence to recall visits, and the presence of plaque were associated with higher peri-implant probing-depth values. The maximum soft tissue recession was recorded at sites with a thin biotype and shallow vestibular depth (P = .0). The logistic regression analysis revealed that plaque (P = .002) and vestibular depth (P = .043) were significantly associated with peri-implantitis. Within the study limitations, patients with high plaque accumulation and shallow vestibular depth are more prone to peri-implant disease. more...