Frontiers in Dentistry最新文献

Objectives: The present study aimed to investigate the effect of preheating on the color stability and surface roughness of a silorane-based composite resin. Materials and Methods: A total of 44 Filtek P90 composite resin disks, (10mm×1mm), were fabricated using plastic molds and were divided into two groups. In group 2, the composite resin syringes were placed in a thermostatically controlled water bath at 55‒60°C before preparing the disks. After polishing the samples with silicon carbide papers, they were stored in distilled water for 48 hours. Roughness and color parameters were then measured in two stages: immediately after retrieval from distilled water and after 40 days of storage in tea solution. Finally, the differences in roughness and color parameters were recorded. Independent sample t-test and regression analysis were used at a significance level of P<0.05. Results: Based on the findings of the present study, there was no significant difference among the mean ∆E values (P=0.4); however, a significant difference in mean surface roughness (P=0.01) was found between the two groups. Regression analysis showed a significant relationship between the study groups in terms of surface roughness and ΔE values​ (preheated: r² = 0.73; non-preheated: r²= 0.76). Conclusion: Filtek P90 silorane-base composite showed ΔE>3.3 and surface roughness above 0.2µ under preheated and non-preheated conditions and discoloration increased following preheating.

Teledentistry is a type of telemedicine and telehealth that aims to make all major specialties of the discipline easier through a remote approach to prevention and treatment of oral and dental issues. This new method enables distant access to individuals instead of direct, face-to-face, doctor-patient contact and has been made possible thanks to developments in information technology. Teledentistry was described in 1997 as "… the practice of using video-conferencing technologies to diagnose and provide advice about treatment over a distance", and today it represents a modern way to practice dentistry by integrating digital imaging, electronics, health records, and telecommunications technology via an internet connection. This approach facilitates patients' access to care in remote settings and also enables specialists at distant locations to arrive at a correct diagnosis as well as to propose proper therapy or refer patients, where warranted. The current brief report aims to describe the present and future of this modern approach in dentistry and its advantages in patient management from prevention to diagnosis to treatment.

Acute traumatic injuries to the maxillary incisors may lead to a crown-root fracture. If the fracture is left untreated, the fracture line will propagate and extend apically, resulting in microbial contamination of the attachment apparatus and subsequent bone loss. In cases with extensive periodontal involvement, extraction has been suggested. However, bonding and sealing the fracture line with a biocompatible material seems to be an effective alternative treatment option. In this case report, management of a central incisor with an incomplete crown-root fracture that showed signs and symptoms of vertical root fracture is discussed. As the extension of the fracture line was not clear, intentional replantation and sealing the fracture line with a glass ionomer was performed. The tooth showed no signs and symptoms at six-month follow up, and the radiographic examination exhibited substantial bone repair.

The main goals of treatment of dentofacial deformities are to achieve optimal esthetics and ideal functional occlusion. The conventional orthognathic surgical approach includes a long presurgical orthodontic phase, which takes about 18 months. During this phase, the patients' appearance is deteriorated and their motivation to continue treatment significantly decreases. In the surgery first approach (SFA), orthognathic surgery is performed prior to orthodontic treatment, and orthodontic treatment is performed postoperatively to improve dental occlusion and for final settling. The SFA has two main advantages namely shortening of treatment period, and early improvement of the appearance of patient. The SFA has significant advantages especially for class III patients. This study aimed to review the available articles on this topic published from 2012 to 2019 to achieve a comprehensive understanding of different aspects of the SFA. The databases were searched by two researchers and a total of 11 eligible articles were selected for study inclusion. The results were categorized into two categories of stability of the results of the SFA, and duration of treatment, in comparison with the conventional approach. Although different aspects of the SFA have been previously evaluated by dental clinicians, a considerable gap of information still exists regarding the details of this approach, which calls for further research in this respect.

Objectives: Parents are aware of the importance of anterior tooth esthetics in their children. Children also pay attention to their appearance more than ever. Today, charcoal has been added to toothpastes. Charcoal can help whiten teeth through abrasion. This study aimed to investigate the degree of bleaching and abrasion of charcoal toothpaste on primary teeth. Materials and Method: This in-vitro study was performed on 30 extracted primary teeth. Initially, the samples were polished, cut, and mounted in blocks of putty. The samples were placed in a coffee solution and then the tooth color was measured by a spectrophotometer and the initial surface profile was measured by a profilometer. The samples were brushed back and forth by the brushing machine with 20 gr Bancer, Beverly, and Colgate toothpastes (mixed with 40 ml of distilled water) for 2000 times (equivalent to 3 times a day for 1.5 months). A color determination was performed again and a second surface profile was measured. The data were analyzed by one-way ANOVA, ANCOVA and paired t-test. Results: The results of this study showed that all three Beverly, Bencer and Colgate whitening toothpastes increased the surface profile and made significant statistical changes in the roughness of dental specimens (P=0.01, P=0.005, P=0.001). The statistical study of the data did not show a significant difference between the groups in terms of abrasion and whitening properties (P=0.78, P= 0.99). Conclusion: Three whitening toothpastes whiten primary teeth and increase their surface roughness. These three toothpastes are not statistically different in terms of abrasion and whitening properties.

The coronavirus disease-2019 (COVID-19) pandemic due to the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has casted a deep impact on every aspect of the human life all over the world. The healthcare professionals dealing with the patients have been at the greatest risk of exposure. Dental practitioners fall among the highest risk practitioners because of their field of operation being around the oropharyngeal region of patients, as well as due to the risk of generation of aerosols during various dental procedures. There is a continuous urgent need of modifying the dental practice in accordance with the guidelines issued by the health authorities time to time. Meticulously planned approaches, and adequate precautions and modifications need to be introduced into dental practice. The field of orthodontics also demands a high level of practice modification in order to ensure proper infection control for patients, practitioners, and dental staff.

Objectives: This study compared the effects of fluoride mouthwashes on surface topography of orthodontic wires, and static and kinetic frictional forces between the stainless steel (SS) orthodontic brackets and SS and nickel-titanium (NiTi) archwires. Materials and Methods: This in vitro, study evaluated 240 standard SS maxillary central incisor brackets and 0.018, and 0.025×0.019 inch NiTi and SS archwires. The wire-bracket sets (different combinations of wire diameters and types) were exposed to artificial saliva (control), 0.05% sodium fluoride (NaF) for 1 minute daily, or 0.2% NaF for 1 minute, weekly (37°C) for 3 months. The wires were pulled in bracket slots by 5 mm in a universal testing machine (10 mm/minute). The static and kinetic forces were measured. The surface topography of wires was inspected under a scanning electron microscope (SEM; x500). Data were analyzed by SPSS 25. Results: The mean static and kinetic frictional forces of 0.025×0.019 inch NiTi wire in 0.05% NaF group were significantly greater than SS wire (P=0.000). The mean kinetic frictional force in 0.05% NaF was significantly greater than 0.2% NaF and artificial saliva for all wires (P=0.001). The mean static and kinetic forces in 0.2% NaF were significantly greater than in artificial saliva (P=0.025). In all groups, larger wires showed higher mean frictional forces (P=0.000). SEM results revealed higher wire surface roughness in 0.05% NaF followed by 0.2% NaF group. Conclusion: Weekly use of 0.2% NaF mouthwash is recommended during sliding mechanics to minimize frictional forces between the SS and NiTi wires and SS brackets.

Objectives: Maxillary sinus pathological conditions, like thickening of the Schneiderian membrane, can influence the outcomes of augmentation procedures and implant treatment. The present study aimed to evaluate the relationship between the residual ridge height and maxillary sinus membrane thickening. Materials and Methods: A total of 240 cone-beam computed tomography (CBCT) images of the maxillary sinus of 141 patients (62.1% males and 37.9% females, bilateral in 99 patients and unilateral in 42 patients) who were candidates for implant placement were evaluated. The CBCT scans were subsequently assessed for the following variables: residual ridge height, sinus membrane thickening at future implant(s) site(s), the ostium patency, and presence of periapical lesion adjacent to the edentulous area. Results: The total prevalence of sinus membrane thickening (66.2%) was sub-classified as follows: flat in 53.7%, polypoid in 12.1%, and complete opacification in 0.4%. The prevalence of sinus membrane thickening was higher in male participants. It was revealed that age had no significant relationship with presence of a periapical lesion or sinus membrane thickening (P>0.05). Membrane thickening was detected in all sinuses with obstructed ostium. Reduced residual ridge height was significantly associated with higher sinus membrane thickening at the second premolar and first molar sites (P<0.05). Conclusion: Maxillary sinus membrane thickening (mostly with flat appearance) is frequently observed on CBCT scans taken prior to augmentation and implant placement. This, in return, may trigger a reduction in ridge height.

Objectives: We aimed to find the main concerns of patients undergoing active orthodontic treatments and their orthodontic treatment-related (OTR) problems during the coronavirus disease-2019 (COVID-19) pandemic.

Materials and methods: A researcher-made questionnaire addressing several aspects of the effects of COVID-19 pandemic on treatment was distributed among 181 orthodontic patients receiving active treatment. Anxiety, concern, problems, and willingness to attend orthodontic appointments and to undergo other dental procedures was questioned. The correlation of gender, age, COVID-19-related anxiety and OTR anxiety was statistically analyzed. Patient satisfaction level with different aspects of dental-clinic performance was also evaluated.

Results: The participants included 117 females and 64 males, of which 94% adhered to the pandemic restrictions. The mean COVID-19-related- and OTR-anxiety were 51.7% and 52.7%, respectively. Higher COVID-19-related anxiety was significantly correlated with higher OTR anxiety (P<0.001). There was an inverse correlation between general COVID-19-related anxiety and OTR anxiety and willingness to attend orthodontic appointments (P<0.05). A positive insignificant (P=0.07) correlation existed between age and willingness to attend appointments. The main concern was prolongation of treatment and the most common problem was irritation of oral soft tissues by appliances. The majority (65.3%) were willing to attend their orthodontic appointments. Orthognathic surgery (62%) had the highest while, dental restorations and radiography had the lowest refusal rates (9.9%).

Conclusion: COVID-19 pandemic significantly affected orthodontic treatment. The level of COVID-19-related anxiety was moderately high and patients were concerned about the impact of lockdown on their orthodontic treatment outcome. Young adults demonstrated higher levels of stress than other age-groups.

Oral biofilms are a group of healthy synergistic organisms, that on interplay with the immune system undergo transition and colonize the pathogenic bacteria, leading to various diseases like dental caries, gingivitis, periodontitis and a few systemic conditions. Dental caries being the most common disease of the oral cavity, comprise a heterogeneous group of bacteria that can cause imbalance in the biofilm. Caries prevention has been in research for decades, where antibiotics, chemical biocides and fluoride-antimicrobial approaches have not been adequate for this multifactorial disease. In recent years, the major focus of caries prevention has been shifted to plaque-biofilm modification as an ecological approach that would prevent bacterial colonization. Saliva produces various natural antimicrobial peptides that can regulate biofilm modification. Synthetic production of antimicrobial peptides concentrates on selective elimination and a targeted approach towards cariogenic pathogens, precisely Streptococcus mutans (S. mutans). A search in Medline/PubMed, EBSCO and ScienceDirect databases on C16G2, antimicrobial peptides (AMPs) and S. mutans, using MeSH (Medical Subject Heading) terms was performed and papers published until 2020 were included for further evaluation. A total of eight articles written in English with available full texts were selected based on the search strategy. They included four publications on AMPs against S. mutans and another four articles on AMPs in caries prevention. This review focuses on C16G2 antimicrobial peptide and its potential to modify biofilm and inhibit the targeted bacteria causing dental caries.