Cone beam computed tomography (CBCT) provides a 3-dimensional (3D) view of the patient and has a high frequency of incidental findings (IFs) that do not relate to the area of interest. Many of these IFs are not always visible on 2-dimensional (2D) intraoral or panoramic radiographs. Thus, the aim of the present study was to assess the IFs that did or did not appear on 3D vs 2D images. Significant IFs were recorded from a review of 510 CBCT reports by board-certified oral and maxillofacial radiologists. The IFs on CBCTs with 5-, 8-, and 11-cm fields of view (n = 170 per group) were recorded. A subset of these significant IFs was also viewed on intra-oral and panoramic radiographs to determine whether they were or were not visible in 2D imaging. A total of 677 significant IFs were discovered on 302 (59.2%) of the 510 reports. When a subset of 293 IFs was reviewed on intraoral and panoramic imaging, 112 (38.2%) were not visible on 2D radiographs, while 50 (17.1%) could not be confirmed with certainty. The frequency of significant IFs on CBCT imaging is high and increases with larger fields of view. A substantial number of these findings could not be seen on 2D radiographs, implying that many IFs are visible only on 3D images. Clinicians who order CBCT scans need to carefully review the volume in its entirety, regardless of previous imaging, so as not to miss any significant and relevant findings.

Polyetheretherketone (PEEK) resin is a high-performance thermoplastic polymer that has been introduced as a possible candidate to replace metallic components in dental prostheses. The objective of this integrative review was to compare, through analysis of studies in the literature, the mechanical performance of removable partial denture frameworks and clasps manufactured with PEEK with the performance of cobalt-chromium (Co-Cr) frameworks and clasps. The guiding question was, "Does the use of PEEK as a substitute for Co-Cr alloys for the construction of removable partial denture frameworks result in better mechanical properties?" The PubMed/ MEDLINE, Embase, Web of Science, Scopus, and SciELO databases were searched for articles published through October 2021. The JBI Critical Appraisal Checklist for Quasi-Experimental Studies was used to assess the methodologic quality of the selected in vitro studies. A total of 208 articles were identified. After the exclusion of duplicates and articles that did not meet the inclusion criteria, 7 studies- -4 in vitro and 3 three-dimensional finite element analyses- -published between 2012 and 2021 were included in the integrative review. The appraisal checklist revealed that the reviewed studies had a low risk of bias and high methodologic quality. The results of the review showed that PEEK alloys have adequate mechanical properties for use in clasps and removable partial denture frameworks, but Co-Cr alloys exhibit better mechanical properties and are more suitable in most circumstances.

The aims of this study were to evaluate the prevalence of temporomandibular disorders (TMDs) in children between 6 and 12 years of age in the city of Qom, Iran, and explore the associations between TMDs and both malocclusion and anxiety. This study was conducted in 193 children who were assessed via interview, clinical examination, and the parent version of the Spence Children's Anxiety Scale. Clinical examinations consisted of assessment of asymmetry, joint sounds, jaw movements (functional shift, temporomandibular joint pain on opening, limitations on mouth opening, and mandibular deviation from midline on mouth opening), and masticatory muscles (sensitivity of masseter and temporalis muscles on palpation and dysfunction of pterygoid muscles). The presence of malocclusion and parafunctional habits were also evaluated. The data were analyzed using chi-square and independent t tests. The associations between anxiety and the quantitative variables of the study were analyzed with the Pearson correlation coefficient. The total prevalence of TMDs in this sample was 17.1%. Most children with TMDs had a moderate anxiety level, and the anxiety score had a significant correlation with the presence of TMDs (P = 0.000). There was a significant relationship between Class II malocclusion and TMDs as well as between Class III malocclusion and TMDs. The most common oral habit was placing a pencil or other objects between the teeth. No significant relationships were observed between the prevalence of TMDs and the sex and age groups. This study showed significant relationships between TMDs and anxiety, malocclusion, and parafunctional habits.

The purposes of this study were to examine the distribution and extent of retakes with digital intraoral imaging when operators transitioned from using round to rectangular collimators and to determine the effect of collimator shape on radiation exposure to patients. This study was conducted using digital intraoral radiographic data from 2018 to 2019 in a dental school radiology clinic. Digital intraoral radiography was performed with round collimators during 2018 and then with rectangular collimators in 2019 with the same cohort of students. Exposure values were obtained, and effective doses were calculated. Although the number of retakes increased with the transition from round to rectangular collimators, the transition also resulted in a statistically significant reduction in the overall effective dose for patients (P < 0.01; Pearson chi-square test), with an average difference of 60% between round and rectangular collimators. Even with the increase in the number of retakes, a decrease in effective dose was observed when rectangular collimation was used. Most retakes were due to placement errors, defined as missing contact points, missing apices of teeth, or a missing area of interest. As students gained more experience and practice with rectangular collimation, the number of retakes decreased. With proper clinical and didactic training and emphasis on the importance of rectangular collimation, a transition from round to rectangular collimation can be achieved with a minimal initial increase in retakes and subsequent normalization of rates, resulting in a significant reduction of the radiation dose to patients.

The objectives of the present study were to compare measurements of pharyngeal airway subregions on lateral cephalometric (LC) and cone beam computed tomographic (CBCT) images in relation to skeletal classes and discuss the advantages and disadvantages of these imaging formats for this type of assessment. The CBCT images were assessed via both multiplanar reconstruction (MPR) and 3-dimensional (3D) reconstruction. The LC and CBCT images from 107 patients were classified according to skeletal class: I, n = 35; II, n = 35; and III, n = 37. Linear measurements of the subdivisions of the upper airway were performed on the LC, MPR, and 3D images. In addition, area and volumetric measurements were performed on the MPR images. The relationships among imaging methods, skeletal class, and pharyngeal thirds were assessed by means of a 1-way analysis of variance (α = 0.05). No statistically significant differences in the linear, area, or volumetric measurements of the upper airway subregions were found among the skeletal classes (P > 0.05). For the linear measurements in the oropharynx and hypopharynx, greater values were observed for the LC images than for the MPR and 3D images (P ≤ 0.05). Based on the study findings, MPR images should be preferred for visualization of the pharyngeal airway subregions. However, LC imaging is preferable to 3D reconstruction.

The aim of this study was to compare the sizes of the implant-abutment microgap in Morse taper implants with a straight abutment (ISA group) and Morse taper implants with an angled abutment (IAA group). A total of 19 Morse taper dental implants (3.8 × 11.0 mm) were used with their respective abutments; 10 abutments were angled at 20°, and 9 were straight. The implant-abutment units were immersed in an epoxy resin to form a base and then cross-sectioned until about 50% of the volume was removed. The specimens were analyzed under a scanning electron microscope, and the size of the microgap was measured at 3 regions on each side of the implant, for a total of 6 measurements per specimen. Mann-Whitney U and Kruskal-Wallis tests were used for statistical analysis. In the ISA group, there were no statistically significant differences in the median sizes of the microgap at the different regions of the interface (P > 0.05; Kruskal-Wallis test). The mean (SD) values of the largest and smallest microgaps in the ISA group were 1.64 (1.38) and 0.83 (0.41) μm, respectively. In the IAA group, there was a statistically significant difference in the median sizes of the microgaps at the upper and middle regions on the left side (P = 0.031; Kruskal-Wallis test). The mean (SD) values of the largest and smallest micrograps were 1.43 (0.062) and 0.61 (0.27) μm, respectively. Comparison of the different regions in the ISA and IAA groups revealed that the only statistically significant difference was at the lower region on the right side (P = 0.027; Mann-Whitney U test). The sizes of the microgaps in the ISA and IAA groups were statistically similar in an overall analysis (P > 0.05; Mann-Whitney U test); however, the IAA group showed greater sealing ability. In addition, in both groups in vitro titanium oxide formation was observed at the interface, characterizing a type of cold-weld joint that provides effective implant-abutment sealing.

The aim of this in vitro study was to compare the efficacy and durability of bleaching with diode lasers over a 9-month period. This study evaluated 27 extracted teeth categorized into 3 bleaching groups (n = 9): 940-nm diode laser, 980-nm diode laser, and 40% hydrogen peroxide whitening gel (control). After the baseline color of the teeth was measured using a spectrophotometer, the teeth underwent dental prophylaxis and their color was measured again. Bleaching treatment was then performed. The color of the teeth was measured immediately after bleaching and 1 day (24 hours), 1 week, 1 month, 3 months, 6 months, and 9 months after bleaching. The Commission Internationale de l'Eclairage (CIE) L*a*b* color change (ΔE*) at each timepoint was calculated and compared using repeated-measures analysis of variance. All bleaching techniques effectively whitened the teeth to a clinically perceptible level (ΔE* > 3.3), and there were no statistically significant differences among the groups (P > 0.05). The mean ΔE* values of the laser groups were not significantly different from the mean value of the control group during the 9-month evaluation period (P > 0.05). However, statistically significant differences among the groups were noted when color measurements at the following timepoints were compared: immediately after bleaching vs 1 day; 1 day vs 1 week; and 3 months vs 6 months (P < 0.05). Use of a 940-nm diode laser, 980-nm diode laser, or conventional hydrogen peroxide gel provided equally effective bleaching. The color change remained clinically perceptible throughout the 9-month period.

The aim of the present study was to evaluate the effect of natural saliva contamination of dentin on the adaptation of composite resin restorations as well as the efficacy of various decontamination techniques. A total of 120 human molars and premolars were randomly distributed into 6 groups (n = 20). Standardized dentin cavities were prepared and restored with composite resin after 1 of 6 different surface treatments, which included a 2-step etch-and-rinse adhesive: 1, dentin etching, adhesive application following the manufacturer's instructions (control), light curing; 2, dentin etching, saliva contamination, air drying, adhesive application, light curing; 3, dentin etching, saliva contamination, water rinsing, air drying, adhesive application, light curing; 4, dentin etching, adhesive application, light curing, saliva contamination, air drying; 5, dentin etching, adhesive application, light curing, saliva contamination, water rinsing, air drying; or 6, dentin etching, adhesive application, light curing, saliva contamination, water rinsing, air drying, adhesive reapplication. The adaptation was evaluated at the top surface and at depths of 0.5 and 1.0 mm by measuring the length of the debonded margin and calculating its percentage relative to the cavity perimeter (%DM). The internal adaptation was evaluated by measuring the width of the maximum marginal gap (MMG). Inferior adaptation was observed after saliva contamination took place. Group 1 presented the most satisfactory adaptation at the top surface, whereas groups 4 and 5 had the highest %DM and greatest MMG at all surfaces (P < 0.05). The %DM and MMG values in groups 2, 3, and 6 were not significantly different from those of group 1 or each other. Saliva contamination after adhesive application (groups 4 and 5) resulted in deterioration of marginal and internal adaptation. Reapplication of the adhesive restored adaptation, as evidenced by the %DM and MMG values in group 6.