OBJECTIVES: The aim of the study was to evaluate the deviation of implant placement performed with a surgical guide fabricated by means of the rapid prototyping technique (the PolyJet™ technology).
MATERIAL AND METHODS: Twenty sheep mandibles were used in the study. Pre-surgical cone-beam computed tomography (CBCT) scans were acquired for the mandibles by using the Kodak 9000 3D cone-beam system. Two implants with dimensions of 4 mm in diameter and 10 mm in length were virtually planned on the 3D models of each mandible by using the Mimics software, v. 16.0. Twenty surgical guides were designed and printed using the PolyJet technology. A total of 40 implants were placed using the surgical guides, 1 on each side of the mandible (2 implants per mandible). The post-surgical CBCT scans of the mandibles were performed and superimposed on the pre-surgical CBCT scans. The amount of deviation between the virtually planned placement and the actual implant placement was measured, and a descriptive analysis was done.
RESULTS: The results showed that the mean deviation at the implant coronal position was 1.82 ±0.74 mm, the mean deviation at the implant apex was 1.54 ±0.88 mm, the mean depth deviation was 0.44 ±0.32 mm, and the mean angular deviation was 3.01 ±1.98°.
CONCLUSIONS: The deviation of dental implant placement performed with a 3D-printed surgical guide (the PolyJet technology) is within the acceptable 2-millimeter limit reported in the literature.
OBJECTIVES: The aim of this in vitro study was to evaluate the long-term effects of various staining solutions on the color stability of different temporary materials produced with the computer-aided design and computer-aided manufacturing (CAD/CAM) technology.
MATERIAL AND METHODS: In the study, the following materials were used: VITA CAD-Temp® (group 1); Ceramill® Temp (group 2); and Telio® CAD (group 3). Forty disk-shaped specimens (10 mm in diameter, 2 mm in thickness) of each material (N = 120) were produced with a CAD/CAM system. Staining solutions - of tea (A), of coffee (B) and cola (C) - and distilled water (D, control) were used, and color was evaluated before and after storing the samples in the solutions. Measurements were taken with a spectrophotometer and the color parameters (L*, a*, b*, and ΔE) were calculated according to the Commission internationale de l'éclairage system (CIELab). The results were evaluated with the two-way analysis of variance (ANOVA) and Tukey's tests (α = 0.05).
RESULTS: Clinically perceivable (ΔE00 > 0.8) and statistically significant (p < 0.001) color differences were detected in all specimens. The highest ΔE00 value was found in the Ceramill Temp specimens. In addition, the highest ΔE00 values were noted for the specimens stored in cola and the coffee solution for all groups. The lowest ΔE00 value was observed for the groups stored in the tea solution.
CONCLUSIONS: Clinically perceivable color changes were observed in all the specimens kept in the solutions. Color changes were greater for cola and coffee as compared to tea.
OBJECTIVES: The aim of the study was to evaluate the effect of fiber post location on fracture resistance and failure mode of endodontically treated premolars with 2 roots.
MATERIAL AND METHODS: Fifty extracted maxillary first premolars with 2 roots were divided randomly into 5 groups. Group 1 was comprised of sound teeth, which received only metal crowns (control). Teeth from groups 2, 3, 4, and 5 were decoronated 2 mm above the cementoenamel junction (CEJ) and were endodontically treated. No post was placed in group 2 teeth. Teeth from groups 3, 4 and 5 were given a fiber post placed in the buccal canal, palatal canal, and both buccal and palatal canals, respectively. All teeth in groups 2, 3, 4, and 5 were built up with composite and full coverage metal crowns. A compressive static load was applied at an angle of 25° to the crowns with a crosshead speed of 0.5 mm/min, until fracture.
RESULTS: One-way analysis of variance (ANOVA) showed significant differences among the groups (p = 0.002). A post hoc test showed significantly lower fracture resistance of group 4 compared to group 5 (p = 0.011). Furthermore, group 2 had significantly less fracture resistance compared to group 1 (p = 0.021) and group 5 (p = 0.002). According to Fisher's exact test, different post locations are non-significantly associated with fracture mode (p = 0.256).
CONCLUSIONS: Fiber post location has a significant effect on fracture resistance of severely damaged, endodontically treated maxillary premolars with 2 roots. However, post placement in the palatal root is preferred, as it maintains the restorability of the tooth.
OBJECTIVES: The aim of this study was to assess the risk of infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during AGPs, and to examine the association between risk severity and the number of AGPs performed per day. The efficacy of personal protective equipment (PPE) was also assessed.
MATERIAL AND METHODS: This cross-sectional cohort study was based on an online questionnaire form completed by 629 general and specialized dentists between January 1 and February 28, 2021. The collected data referred to the sources of COVID-19 infection, the type of PPE used and the number of AGPs performed each day by dental healthcare professionals (DHCPs). For each question, the absolute numbers of responses as well as percentages were calculated.
RESULTS: Among the 629 DHCPs, 113 (17.97%) contracted COVID-19. The risk of contracting COVID-19 during AGPs was the same as in the case of non-AGPs, and the infection risk was not associated with the number of AGPs performed per day. The efficacy of a surgical mask with a face shield/eye goggles was higher in comparison with all other types of PPE. Differences in the infection risk across the different types of PPE used were statistically significant (p < 0.001).
CONCLUSIONS: The risk of COVID-19 transmission during AGPs is the same as in the case of non-AGPs. Thus, restrictions on the performance of elective AGPs should be lifted. On the other hand, the best protection during AGPs is provided by a surgical mask with a face shield/eye goggles.
OBJECTIVES: The aim of the study was to determine the prevalence of dental caries and their association with exposure to environmental tobacco smoke (ETS) among 5- to 10-year-old students attending private and government schools.
MATERIAL AND METHODS: A cross-sectional analytical study was conducted among schoolchildren. Data was collected from the primary caregivers using a pre-tested form to assess the ETS exposure under 5 domains based on history: antenatal exposure; exposure during the index period; exposure in the school neighborhood; exposure in restaurants/roadside stalls; and exposure in bus stops/railway stations. Dental caries was assessed based on the World Health Organization (WHO) guidelines from 1997. The association was reported using prevalence ratios (PRs) (95% confidence interval (CI)).
RESULTS: Data was obtained from 211 schoolchildren attending government (39.8%) and private schools (60.2%). The overall prevalence (95% CI) of dental caries was 49.3% (42.5-56.1%). Among all the risk factors evaluated in the study, exposure to ETS was associated with a significantly increased risk of dental caries. The adjusted prevalence ratio (APR) of ETS exposure varied with the mother's educational status and high sugar exposure, although this was statistically insignificant.
CONCLUSIONS: The prevalence of dental caries among schoolchildren aged 5 to 10 years in the city was moderate and similar to the national average. Among the risk factors assessed in the study, antenatal exposure to ETS was found to significantly increase the prevalence of dental caries by 41% after adjusting for other factors. Therefore, it is important to educate parents on the causal role of ETS exposure in dental caries.
OBJECTIVES: The aim of the present article was to review the current literature on the fracture loads and fracture modes of SRCR implant restorations - in vitro studies, and also studies demonstrating the clinical performance of such design.
MATERIAL AND METHODS: A literature search was conducted from January 2000 to June 2022, using 6 databases to identify studies on fracture load and clinical performance that fulfilled the eligibility criteria. Thirty-eight studies met the inclusion criteria (22 in vitro and16 in vivo). The in vivo studies comprised case reports/series/letters (9), clinical techniques (2), retrospective/prospective studies (3), and randomized controlled trials (RCTs) (2).
RESULTS: The reviewed articles reported the effects of the SRCR design on the fracture risk if screw access channels were filled or unfilled, with regard to their diameter, and the preparation before or after glazing. The effect of the type of material used in the construction on the fracture modes SRCR restorations was also reported. The long-term clinical data was mainly retrospective and referred to metal-ceramic constructions. Limited long-term clinical data was available for all-ceramic materials and high-performance polymers (HPPs).
CONCLUSIONS: Screw-retrievable cement-retained implant restorations appear to have potential in the monolithic design. If the SRCR construction is metal-ceramic or made of a veneered material, special design and abutment selection should be considered. High-performance polymers may be recommended as a substitute for posterior implant restoration.
OBJECTIVES: This study used nationally representative samples from the Global School-based Student Health Survey (GSHS) (2010-2019) to determine the frequency of toothbrushing among school-going students (N = 266,113) in 72 countries.
MATERIAL AND METHODS: The country-specific sample size ranged from 130 in Tokelau to 25,408 in Malaysia. The outcome variable was the frequency of brushing or cleaning teeth once daily within the past 30 days prior to the survey. Bivariate analysis was conducted following a descriptive study to determine the frequency of toothbrushing or cleaning across different age groups (≤12, 13, 14, 15, ≥16 years), sexes, World Health Organization (WHO) regions, and gross domestic product (GDP) per capita quintiles.
RESULTS: The overall proportion of males to females in the sample was 50.9:49.1. In 45 countries or territories (62.5%), the proportion of participants who reported brushing their teeth at least once a day was above 90%. Participants from 10 countries or territories (13.9%) reported never or rarely brushing their teeth. In 69 countries or territories (95.8%), male students were more likely than female students to never or rarely brush their teeth. The highest rate of individuals who never or rarely brush their teeth (32.1%) was reported in the Eastern Mediterranean Region. In comparison, the Region of the Americas had the highest frequency of brushing twice or more daily (82.9%).
CONCLUSIONS: Educational interventions focused on dental health implemented in schools and aimed at early adolescents have the potential to promote the formation of healthy habits, which may lead to improved well-being over both short and long terms.