Survival analysis of crown margin repair: A retrospective study in a dental school setting

BackgroundRepairing crowns with defective margins is minimally invasive and cost-effective compared with replacement. The authors’ objectives were to examine the survival trajectory of crown margin repairs and to determine the factors associated with survival.MethodsRecords of adult patients from January 2008 through August 2019 were reviewed for crown margin repairs completed at University of Iowa College of Dentistry. A total of 1,002 crown margin repairs were found. Each repair was followed through the end of study in 2019 or until an event (for example, additional repair, endodontic treatment, crown replacement, or extraction). A Cox proportional hazards model was used to study the relationship between selected covariates and time to event.ResultsDuring the follow-up period, 32.8% of the repairs needed reintervention. In the final model, repair material was the only significant covariate. No difference was found between the survival of repairs done with resin-modified glass ionomer and amalgam. However, the repairs done with resin-based composite and conventional glass ionomer were more likely (1.5 times: 95% CI, 1.02 to 2.10 times; and 2 times: 95% CI, 1.40 to 2.73 times, respectively) to need reintervention than were those done with amalgam.ConclusionsMedian survival time of crown margin repairs was 5.1 years (95% CI, 4.48 to 5.72 years). Median survival times for amalgam, resin-modified glass ionomer, resin-based composite, and glass ionomer repair materials were 5.7 years (95% CI, 4.80 to 6.25 years), 5.3 years (95% CI, 4.73 to 6.34 years), 3.2 years (95% CI, 2.51 to 6.19 years), and 3.0 years (95% CI, 2.53 to 3.62 years), respectively.Practical ImplicationsWhen considering crown margin repairs, resin-modified glass ionomer or amalgam is preferable to resin-based composite or glass ionomer.     

Paediatric pulmonary actinomycosis: A forgotten disease

Actinomycosis is a rare, indolent and invasive infection caused by Actinomyces species. Actinomycosis develops when there is disruption of the mucosal barrier, and invasion and systemic spread of the organism, which can lead to endogenous infection affecting numerous organs. It is known to spread in tissue through fascial planes and most often involves the cervicofacial (55%), abdominopelvic (20%) and thoracic (15%) soft tissue. Pulmonary actinomycosis is rare in patients under the age of five years, with the median reported age in the fifth decade. Clinical findings include chest wall mass (49%), cough (40%), pain (back, chest, shoulders) (36%), weight loss (19%), fever (19%), Draining sinuses (15%) and hemoptysis (9%). Chest x-ray findings in pulmonary actinomycosis are mostly nonspecific and can overlap with pulmonary tuberculosis, foreign body aspiration and malignancy. Endobronchial tissue aggregates may show sulphur granules, with yellow to white conglomerate areas of gram positive Actinomyces. Removal or biopsy of these large endobronchial masses must be done with care, because of the risk of bleeding and large airway obstruction. The cytology on bronchoalveolar lavage fluid may show Periodic acid–Schiff (PAS) positive stain, ZN negative and Gram-positive filamentous bacilli which is morphologically suggestive of Actinomycosis. Actinomyces spp is highly susceptible to beta lactam antibiotics, penicillin G, and amoxicillin. A minimum of 3–6 months is needed but up to 20 months of treatment may be needed. Early diagnosis and correct treatment can lead to a good prognosis with a low mortality.     

The role of orthodontics in management of obstructive sleep apnea

Dental sleep medicine is the field of dental practice that deals with the management of sleep-related breathing disorders, which includes obstructive sleep apnea (OSA) in adults and children. Depending on the developmental age of the patient and the cause of the apnea dental treatment options may vary. For adult patients, treatment modalities may include oral appliance therapy (OAT), orthognathic surgery and surgical or miniscrew supported palatal expansion. While for children, treatment may include non-surgical maxillary expansion and orthodontic functional appliances. Many physicians and dentists are unaware of the role dentistry, particularly orthodontics, may play in the interdisciplinary management of these disorders. This review article is an attempt to compile evidence-based relevant information on the role of orthodontists/sleep dentists in the screening, diagnosis, and management of sleep apnea. Oral sleep appliance mechanisms of action, selective efficacy, and the medical physiological outcomes are discussed. The purpose of this review is to provide a comprehensive understanding of how orthodontists and sleep physicians can work in tandem to maximize the benefits and minimize the side effects while treating patients with OSA.     

Assessment of dental implant surface stability at the nanoscale level

ObjectivesTo study the oxide layer stability of certified dental implants of system "P", made based on TiO₂ alloy with carbon coating. To perform a comparative statistical analysis of the obtained data with the available data for the dental implants of systems "A" and "B".MethodsX-ray microtomography and X-ray fluorescence analysis were used to study soft tissue biopsy specimens. Supernatants were studied by dynamic light scattering and transmission electron microscopy when simulating free emission of nanoscale metal oxide particles from the surface of dental implants as well as when simulating physical loading. A comparative analysis of three parameters of nanoscale particles was performed by statistical data analysis. The surface of the "P" system dental implant with surface treatment was analyzed by scanning electron microscopy.ResultsBoth free emission of nanoscale oxide layer particles and yield of nano- and microscale particles during simulation of physical load were confirmed. Statistically significant differences were noted in a comparative analysis of the size and frequency of occurrence of these particles in the supernatants obtained from the surfaces of three dental implant systems. The elemental composition of the particles and the composition and structure of the "P" system dental implants themselves were analyzed.SignificanceThe developed method of dynamic light scattering can be used to compare the stability of the oxide layer of standardized medical products manufactured on the basis of the TiO₂ alloy.     

Redefining our protocol of the orthognathic surgery-first approach after 10 years of experience

The objective of this study was to update and redefine some concepts of the surgery-first (SF) approach, regarding its indications and contraindications, virtual planning work-up, surgical tips, and postoperative orthodontic benefits, after 10 years of experience. A retrospective analysis was made of orthognathic surgical procedures following the SF protocol between January 2010 and December 2019 to review inclusion and exclusion criteria, diagnostic workflow, surgical tips, and postoperative outcomes. A total of 148 SF procedures were performed during this period, which corresponded to only 9.2% of the total orthognathic surgeries performed, which means that we have broadened the exclusion criteria instead of reducing them. Surgical tips include interdental corticotomies solely in cases of anterior crowding and leaving the intermaxillary fixation miniscrews in place postoperatively for orthodontic skeletal anchorage. The mean duration of postoperative orthodontic treatment was reduced in comparison to conventional surgery (36.8 vs 87.5 weeks). The overall degree of satisfaction was high not only for the patients, but also for the orthodontists and surgeon. SF is especially indicated for patients who desire an immediate aesthetic result, with short-term orthodontics, or for treatment of sleep-related breathing disorders, if they meet the established criteria.     

Evaluation of the effectiveness of bioactive glass fillers against Candida albicans adhesion to PMMA denture base materials: An in vitro study

BackgroundDentures with antimicrobial properties are desirable for preventing Candida albicans adhesion. This study was to assess the effectiveness of bioactive glass (BAG) on C. albicans adhesion, surface roughness, and hardness of denture base materials.MethodsHeat-polymerized (HP) and autopolymerized (AP) acrylic resins were used to fabricate 240 disk specimens (120/material, 60/C. albicans, 60/surface roughness and hardness). Specimens were divided into five groups (n = 10) based on the BAG concentration: 0.5, 1.5, 3, 5, and 7.5 wt% of the acrylic powder, with a control group comprised of unmodified specimens. Direct culture method was used to assess C. albicans adhesion. A profilometer and Vickers hardness test were used to measure surface roughness and hardness respectively. Analysis of variance (ANOVA) and post hoc Tukey’s test were used for data analysis (α = 0.05).ResultsBAG addition significantly decreased the C. albicans count when compared with the control group (P < 0.001) for both HP and AP. Regarding surface roughness, there was no change in the HP acrylic resins (P > 0.05), while the AP acrylic resins exhibited significantly higher surface roughness with BAG addition (P < 0.001). The hardness of the HP and AP acrylic resins were significantly higher with the addition of BAG (P < 0.001).ConclusionsThe addition of BAG to HP and AP acrylic resins effectively decreases C. albicans adhesion. The roughness of AP acrylic resins increases with the addition of BAG, while the hardness of both HP and AP acrylic resins increase with the addition of BAG.     

A Review of Aerosol Generation Mitigation in International Dental Guidance

IntroductionThe coronavirus disease 2019 (COVID-19) led to the worldwide closure of dental practices or reduction of dental services. By the end of April 2020, governments and professional organisations were publishing recommendations or guidance for the reopening/restructuring of dental services. The aim of this study was to assess how dental aerosol-generating procedures (AGPs) were defined in international dental guidelines, what mitigation processes were advised, and whether they were linked to COVID-19 epidemiology.MethodsElectronic searches of a broad range of databases, along with grey literature searches, without language restriction were conducted up to 13 July 2020. Recommendations for the use of face masks and fallow times with patients without COVID-19 were assessed against the deaths per 1 million population in the included countries and country income level using Pearson Chi-squared statistics.ResultsSixty-three guidance documents were included. Most (98%) indicated that AGPs can be performed with patients without COVID-19 with caveats, including advice to restrict AGPs where possible, with 21% only recommending AGPs for dental emergencies. Face masks were recommended by most documents (94%), with 91% also specifying the use of goggles or face shields. Fallow periods for patients without COVID-19 were mentioned in 48% of documents, ranging from 2 to 180 minutes. There were no significant differences in recommendations for face masks or fallow time in patients without COVID-19 by country death rate (P = .463 and P = .901) or World Bank status (P = .504 and P = .835). Most documents recommended procedural or environmental mitigations such as preprocedural mouthwash (82%) and general ventilation (52%). Few documents provided underpinning evidence for their recommendations.ConclusionsWhile the amount of high-quality direct evidence related to dentistry and COVID-19 remains limited, it is important to be explicit about the considered judgements for recommendations as well as generate new evidence to face this challenge.