The synergy between dentistry and informatics has allowed the emergence of new technologies, specifically 3D printing, which has led to the development of new materials. The aim of this research was to compare the mechanical properties of dental base resins for 3D printing with conventional ones. This systematic review was developed using the PRISMA guidelines, and the electronic literature search was performed with the PubMed/MEDLINE, Web of Science—MEDLINE and EMBASE databases, until 30 April 2022. Two researchers selected the studies independently, and thus eight articles were found eligible for analysis. A meta-analysis was developed to estimate flexural strength. The Cohen’s kappa corresponding to this review was 1.00, and the risk assessment was considered low for the included studies. The 3D printing resin presented lower values of flexural strength and hardness compared with the heat-cured resin. Regarding impact strength, a lower value was recorded for the heat-cured resin compared with the 3D printing resin. Three-dimensional printing resins are viable materials for making prosthetic bases but need further clinical research.

Denture-related stomatitis (DRS) is the most common condition affecting removable-denture wearers, andCandida albicansthe most frequent pathogenic agent. Systemic antifungal treatment is indicated but recurrences are frequent. The aim of this study was to characterize the oral load, fluconazole susceptibility profile and genotypic variability of oralC. albicansisolates from patients with DRS before (T0), immediately after fluconazole treatment (Tat) and after 6-months follow-up (T6m). Eighteen patients presenting DRS and treated with fluconazole were followed at the Faculty of Dentistry of Oporto University. SeventyC. albicansisolates were obtained and identified using standard cultural and biochemical multi-testing. Fluconazole susceptibility was tested by E-test^®. Microsatellite-primed PCR was performed to assess the genotypic variability ofC.albicansisolates. The patients’ mean age was 58.0±3.2 years, and 55.6%/44.4% had total/partial dentures. Before treatment, 22.2%, 44.4% and 33.3% of the patients presented DRS type I, II or III, respectively. Fluconazole treatment healed or improved DRS in 77.8% of the patients, accompanied by an 83.5% reduction in oralC. albicansload. However, after 6-months, oralC. albicansload increased significantly and DRS severity was similar to the one observed before treatment. Moreover, the prevalence of patients presenting fluconazole resistant isolates ofC. albicansincreased significantly throughout the study: T0-5.6%, Tat-10.0% and T6m-42.9%. A change in the genotypic variability ofC. albicansisolates was also verified, being mostly associated to fluconazole susceptibility profile change. In conclusion, fluconazole presents a good short-term DRS treatment efficiency, but may be associated to a long-term emergence ofC. albicansfluconazole resistance.

This investigation aims to determine the effect of the same polishing protocol on the surface roughness (Ra) of different resins obtained by different processing techniques. Acrylic resins obtained by CAD/CAM technology overcame the disadvantages identified in conventional materials. A total of thirty samples (six of each resin): self-cured, heat-polymerized, injection molded, CAD/CAM 3D-printed and CAD/CAM milled were prepared. JOTA^® Kit 1877 DENTUR POLISH was used to polish the samples by two techniques: manual and mechanized, with a prototype for guided polishing exclusively developed for this investigation. The Ra was measured by a profilometer. The values were analyzed using ANOVA, Games–Howell post-hoc test and One-sample t-test, with p < 0.05. Manual polishing produces lower values of Ra compared to mechanized polishing, except for injected molded resins (p = 0.713). Manual polishing reveals significant differences between the resin pairs milling/3D-printing (p = 0.012) and thermopolymerizable/milling (p = 0.024). In the mechanized technique only, significant differences regarding the R_a values were found between the self-cured/3D-printed (p = 0.004) and self-cured/thermopolymerizable pair resins (p = 0.004). Differences in surface roughness values can be attributed to the inherent characteristics of the resin and the respective processing techniques.

Background: The upper airways are formed by the nasal cavities, pharynx, and larynx. There are several radiographic methods that allow evaluation of the craniofacial structure. Upper airway analysis in cone-beam computed tomography (CBCT) may be useful in diagnosing some pathologies such as obstructive sleep apnea syndrome (OSAS). OSAS prevalence has increased significantly in recent decades, justified by increased obesity and average life expectancy. It can be associated with cardiovascular, respiratory, and neurovascular diseases, diabetes, and hypertension. In some individuals with OSAS, the upper airway is compromised and narrowed. Nowadays, CBCT is widely used in dentistry by clinicians. Its use for upper airway assessment would be an advantage for screening some abnormalities related to an increased risk of pathologies such as OSAS. CBCT helps to calculate the total volume of the airways and their area in different anatomical planes (sagittal, coronal, and transverse). It also helps identify regions with the highest anteroposterior and laterolateral constriction of the airways. Despite its undoubted advantages, airway assessment is not routinely performed in dentistry. There is no protocol that allows comparisons between studies, which makes it difficult to obtain scientific evidence in this area. Hence, there is an urgent need to standardize the protocol for upper airway measurement to help clinicians identify at-risk patients. Objective: Our main aim is to develop a standard protocol for upper airway evaluation in CBCT for OSAS screening in dentistry. Methods: To measure and evaluate the upper airways, data are obtained using Planmeca ProMax 3D (Planmeca). Patient orientation is performed in accordance with the manufacturer's indications at the time of image acquisition. The exposure corresponds to 90 kV, 8 mA, and 13,713 seconds. The software used for upper airway analysis is Romexis (version 5.1.O.R; Planmeca). The images are exhibited in accordance with the field of view of 20.1×17.4 cm, size of 502×502×436 mm, and voxel size of 400 μm. Results: The protocol described and illustrated here allows for automatic calculation of the total volume of the pharyngeal airspace, its area of greatest narrowing, its location, and the smallest anteroposterior and laterolateral dimensions of the pharynx. These measurements are carried out automatically by the imaging software whose reliability is proven by the existing literature. Thus, we could reduce the possible bias of manual measurement, aiming at data collection. Conclusions: The use of this protocol by dentists will allow for standardization of the measurements and constitutes a valuable screening tool for OSAS. This protocol may also be suitable for other imaging software. The anatomical points used as reference are most relevant for standardizing studies in this field. International Registered Report Identifier (IRRID): RR1-10.2196/41049