European Oral Research最新文献

Purpose: This study aims to evaluate the antimicrobial effects of the cholecalciferol vitamin D3 against Streptococcus sobrinus (Strep. sobrinus) and Streptococcus mutans (Strep. mutans) bacteria in vitro that is considered the main causative bacteria in dental caries development.

Materials and methods: The antimicrobial effects of vitamin D3 were evaluated against Strep. sobrinus and Strep mutans using the agar disc diffusion method. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of vitamin D3 were determined using a microdilution method following the guidelines by the Clinical Laboratory Standards Institute (CLSI). Scanning electron microscope (SEM) was used to evaluate the morphological changes of bacterial cells following exposure to vitamin D3.

Results: Strep. sobrinus was more sensitive to vitamin D3 compared to Strep. mutans bacteria. The MIC values of vitamin D3 against Strep. sobrinus and Strep. mutans were 60 μg/ mL and 250 μg/mL respectively whereas the MBC values were 120 μg/mL and 500 μg/mL, respectively. Moreover, significant changes in the bacterial morphology were observed in treated bacterial cells with vitamin D3 as compared to the untreated control bacteria using SEM.

Conclusion: These findings suggested that vitamin D3 has excellent antimicrobial effects against Strep. sobrinus and Strep. mutans and may be considered as a promising compound in the prevention of dental caries in the future. Further research is recommended to elucidate the mechanism of vitamin D3 on these bacteria.

Purpose: To describe the prevalence and pattern of traumatic dental injuries (TDIs) among Turkish children in a web-based and multicenter design using Eden Baysal Dental Trauma Index (EBDTI).

Materials and methods: The study sample consisted dental trauma patients aging 1-15 years and a webbased form was developed and used to record the information of the patients' clinical and radiographic findings including EBDTI. The obtained data also included patient gender, age at the initial date of trauma, date of trauma, cause of injury and emergency treatment. Data were analyzed using Pearson Chi-square and Fisher's exact tests.

Results: A total of 280 traumatized teeth in 252 patients were evaluated. Dental trauma was seen more in boys and 7-10 years age group (p<0.05). There were significant differences between permanent and deciduous teeth with regard to uncomplicated and complicated crown fracture rate (p<0.05). The root fractures were mostly located at the apical third of the root in both dentitions.

Conclusion: TDI was associated with age, gender, and type of dental trauma. EDBTI provided easy and proper recording of multiple dental injuries and maturity of the apex and it was found to be a very useful tool to facilitate online recordings of dental injuries.

Purpose: The purpose of this study was to evaluate the relationship between idiopathic coronal resorption and age in adult patients.

Materials and methods: 3405 digital panoramic radiographs present in the archive of the radiology department belonging to 1584 males and 1821 females aged 25 and over were assessed by two oral and maxillofacial radiologists. The patients' age, gender, number of impacted teeth, number and position of teeth with idiopathic coronal resorption and the extent of coronal resorption were recorded on standard forms.

Results: A thousand and nine impacted teeth were observed in 622 patients (304 males and 318 females) with a mean age of 36,92 (±10,85). Idiopathic coronal resorption was present in 26 of the 622 patients with a frequency of 4.2%. One patient had two teeth with idiopathic coronal resorption; resulting in as 27 teeth and a frequency of 2.7% according to tooth number. There were 13 (50%) females and 13 (50%) males having idiopathic coronal resorption. There was no significant difference between genders. The presence of idiopathic coronal resorption increased with advanced age (v: 0,193, p<0.05). There was no statistically significant difference between the extent of the coronal resorption and age.

Conclusion: The presence of idiopathic coronal resorption increases with advancing age. Idiopathic coronal resorption is detected incidentally during radiographic examination. Thus, dentists should consider this situation and should perform periodically radiographic examination of impacted teeth.

Purpose: The objective of this study was to determine whether the addition of different types of boron (Borax, Boric Acid and Colemanite) to polymethyl methacrylate denture base resin would improve flexural and impact strengths, and surface hardness of polymethyl methacrylate.

Materials and methods: Borax, Boric acid, Colemanite were added to heat polymerized polymethyl methacrylate specimens were prepared for flexural strength (65x10x2.5 mm), impact strength (50x6x4 mm), and hardness (20x6x4 mm) tests according to the manufacturers' instructions (n=10). To determine flexural strength of the specimens, they were loaded until failure on a universal testing machine using a three point bending test. Specimens were subjected to the Charpy impact test machine. Hardness of the specimens was measured with an analog shoremeter Shore D. The data were analyzed with Kruskal-Wallis and Mann-Whitney U tests (α=0.05).

Results: The highest mean flexural strength value was seen in 3% Borax group and followed by 1% Colemanite group. In addition, the highest mean impact strength value was recorded in 1% Colemanite group, and differences between 1% Colemanite group and control group were found to be statistically significant (p=0,001). Furthermore, there was significant difference in hardness between control group and all other groups (p<0.001).

Conclusion: The addition of 1% Colemanite to polymethyl methacrylate improved the mechanical properties of PMMA.

Purpose: To evaluate the temperature changes in primary teeth pulp chambers of different dentin thicknesses during polymerization of four glass ionomer-based restorative materials.

Materials and methods: Eighty extracted, caries‑free, primary molars were prepared as standardized Class I occlusal cavities with dentin thicknesses of 1 mm and 2 mm. Four glass ionomerbased restorative materials, Dyract XP, Photac Fil Quick Aplicap, Fuji II LC, and GCP Glass Fill, were placed in the cavities and cured with two light-curing units. Temperature increases (initial temperature, 37°C) in the pulp chamber during polymerization were recorded by a J-type thermocouple in a pulpal microcirculation set-up. The data were analyzed with Variance analyses and Tukey tests.

Results: The temperatures recorded in samples with dentin thicknesses of 1 mm and 2 mm exhibited statistically significant differences (p<0.05). The GCP Glass Fill group exhibited the highest temperature increases for both dentin thicknesses (p<0.05). The other groups were not statistically different but the Dyract XP group exhibited the least temperature change.

Conclusion: The highest temperature changes were observed for 1 mm dentin thickness. All temperature increases during polymerizations and setting reactions were lower than the corresponding critical values 5.5°C.

Purpose: To compare MEP which is originally manufactured for increasing bond strength between organic resins and ceramic with conventional surface treatment methods in preparation of leucite-reinforced FC surfaces regarding shear bond strength (SBS) of stainless steel brackets and the mode of bond failure.

Materials and methods: Forty specimens that were fabricated from FC material and glazed were randomly assigned to four surface conditioning methods: (1) CoJet Sand; (2) MEP; (3) HF acid etching followed by silane coupling agent; (4) Diamond bur followed by silane coupling agent. The SBS was determined using universal testing machine. Bond failure sites were classified according to Adhesive Remnant Index (ARI).

Results: No statistically significant difference (p less than 0.05) was found in SBS between the groups while significant intergroup differences were detected concerning ARI scores (p less than 0.001). Group 1 had ARI score 1 and 2 indicating mode of failure at the adhesive interface with greater percentage of the adhesive left on bracket base. The other groups had higher frequency of ARI score 3 and 2. The quantity of the ARI retained on the ceramic surface was highest in Group 3, followed by Group 4 and Group 2.

Conclusion: MEP can be a suitable alternative for bonding metal brackets to FC surface.

Purpose: The aim of this study was to evaluate the efficacy of endoscopic visualisation to detect the presence and type of isthmuses within the mesial root canals of mandibular first molar teeth compared with micro-computed tomography (micro- CT) images as reference.

Materials and methods: Thirty-two mesial roots of mandibular first molars presenting isthmuses were selected based on micro-CT scans. In all, 12 type I and 20 band-shaped isthmuses were collected. The specimens were mounted in the posterior socket of dental phantom manikin for endoscopic visualisation. The ability of endoscopes to visualize the presence of isthmuses and distinguish the type of isthmuses was compared. Micro-CT images of the specimens were used as references. Data were analyzed using Fisher's exact tests.

Results: Sensitivity of endoscope to detect isthmuses were also calculated for each isthmus type. In 37.5% of the samples, isthmus presence was correctly diagnosed via orthograde endoscopic visualization. Type I istmuses were significantly more detected than band-shaped isthmuses (P<0.05). Endoscope showed higher sensitivity to detect type I isthmus than band-shaped isthmus.

Conclusion: The endodontic endoscope could detect type I isthmuses more accurately than band- shaped isthmuses.

Purpose: The objective of the research was to determine the relationship between root apices and maxillary sinus wall, and to analyze pulpoapical conditions of 2nd premolars, 1st molars, 2nd molars, 3rd molars using cone beam computerized tomography (CBCT).

Materials and methods: This study was conducted on a retrospective manner of CBCT images of 1000 maxillary sinus with 500 subjects, who visited the Department of Dento-Maxillofacial Radiology. The association of each teeth with sinus floor and pulpoapical status were categorized. The association among gender, age, lateralization of sinus cavity were evaluated.

Results: A total of 602 second premolars, 500 first molars, 623 second molars, 347 third molars were evaluated. There were no significant differences between pulpoapical condition of teeth and gender or left and right sides (p=0.065, p=0.072). There were significant associations between pulpoapical condition of all teeth and age (p=0.023), and the relationship of each root with maxillary sinus and age (p=0.037). There was significant association between vertical position and right/left sides in second and third molars (p=0.033).

Conclusion: Age seems to have relationship with periapical condition of teeth, and the association of root with the sinus cavity.

Purpose: An essential of successful dental prosthesis is dental models. Voids present in dental models decreases accuracy and strength. This study investigates void formation in models fabricated by a new technique. The technique described in the study was based upon increasing soaking time of gypsum powder in water.

Materials and methods: Voids in hand mixed, hand mixed after a soaking time of 1.5 minutes and vacuum mixed samples were examined. The voids were counted via a stereomicroscope and diameters of voids were recorded in 2 categories (0.01-0.05mm, 0.051-0.1mm). The amounts of voids were compared between the samples prepared with 3 methods.

Results: The samples prepared by conventional hand mixing method had the highest total number of voids and smaller voids. There was no significant difference between the amount of voids in the samples prepared by soaking powder in water and by mixing under vacuum.

Conclusion: Soaking gypsum powder in water for 1.5 minutes before mixing may be an alternative to mixing gypsum under vacuum to avoid void formation in dental models.