Avicenna Journal of Dental Research
Volume:13 Issue: 4, Dec 2021

The present study aimed to survey the influence of two different bleaching techniques on changes of color, translucency, and whiteness of the four CAD/CAM materials.

The monolithic blocks of Vita Suprinity, Vita Enamic, IPS e.max CAD, and Katana Zirconia were sectioned to discs with thickness of 2 mm (n=30 / each group). Samples from each type of ceramic were assigned to three subgroups: 1) the 40% hydrogen peroxide for 20 minutes; 2) the 16% carbamide peroxide for three hours/day for 2 weeks; and 3) the control. Then CIELab coordinates of each sample were evaluated before and after the intervention by a spectrophotometer. Final color change (ΔE), Whiteness (ΔWI D), and Translucency Parameter (ΔTP) were calculated. Two-way ANOVA test was adopted to analyze the data (α=0.05).

Type of ceramic, bleaching subgroups, and interaction between them had a statistically significant influence on mean values of ΔE, ΔWID. The influence of bleaching subgroup on the mean value of ΔTP was also significant (P<0.001).

Carbamide peroxide 16% for three hours/day and for two weeks caused the most considerable changes in final color, whiteness, and translucency of the all tested CAD/CAM materials. Maximum color change and whiteness were detected in the Vita Enamic, which were clinically unacceptable.

Extending the lifespan and improving the physical properties of dental burs as the most extensivly used instruments have been the subject of several studies. One of the proposed methods is using surface coatings for the burs. Since the dental instruments are reused, they require sterilization. One of the possible causes of the damage to dental burs is autoclaving process. This study aimed to investigate sterilization (autoclave) effect on wear of diamond coated tungsten-carbide burs with different thicknesses.

In this in vitro study, 40 tungsten-carbide dental burs (IQ DENT, Poznan, Poland) were selected, out of which 20 burs were coated with 1.5-μm-like diamond particles, and 20 burs were coated with 3.5-μm by PVD method using Swin Plasma Coating Machine. Then, the burs were randomly divided into four groups (n=10) as follow: G1: 1.5 μm thickness coated burs without sterilization; G2: 3.5 μm thickness coated burs without sterilization; G3: 1.5 μm coated with sterilization; and G4: 3.5μm thickness coated burs with sterilization. Their weights were measured before wear test.Wear test was performed and then they were re-weighted. Data were analyzed using SPSS software (version 21) as well as Two-way ANOVA and Tukey HSD supplementary tests (α=0.05).

Mean and standard deviation of the burs weights without sterilization in the control groups were 7.31±2.63 and 7.96±1.61 mg, respectively; and mean and standard deviation of the burs weights in the sterilization groups were 7.06±0.98 and 7.12±1.11 mg, respectively. The study results showed that “sterilization application” and “thickness of coated layer” were the main factors and their intraction had no statistically significant difference (P=0.589).

The sterilization process had no effect on wear of diamond coated tungsten-carbide burs with different thicknesses.

The exact mechanism of the formation of salivary gland stones is unknown. Elucidating pathophysiology of the formation of salivary stones might prevent both their formation and the need for implementing invasive surgical procedures. Therefore, this study aimed to evaluate the effects exerted by some etiological factors on the formation of salivary gland stones.

In this case–control study, the records of 80 patients with sialolithiasis were studied as a census from April 2011 to June 2019. These patients were referred to the Oral Medicine and the ENT departments of Tabriz University of Medical Sciences. The control group consisted of the same number of the patients with no sialolithiasis. Two groups were compared in terms of stone size, smoking, gallstones, and renal stones. Chi-squared, independent t-test, and Mann-Whitney U test were adopted to examine the quantitative variables. The data were analyzed using SPSS 17. Statistical significance was set at P<0.05.

Overall, 96.2% of sialoliths were found in the submandibular gland, of which 78.8% were single. Moreover, 32.5% of the patients with a history of sialolithiasis were smokers, whereas this frequency was 23.8% in the control group. In the case and control groups, 2.5% and 5% of the patients had a history of renal stones, respectively. Only one patient who had undergone a surgical procedure to remove salivary gland stones had a history of gallstones, while none of the patients in the control group had a history of gallstones.

The results showed that the formation of salivary gland stones was not associated with smoking, history of renal stones, and gallstones. Furthermore, it was found that the numbers and sizes of salivary stones were not affected by smoking

Latent third molar extraction is the most common surgery in dentistry. Common complications of this surgery include pain, swelling, and trismus. To control these side effects, several drugs have been developed and evaluated in various studies. However, the present study is the first one to compare the effects of ibuprofen and ketorolac on pain, swelling, and trismus after molar surgery.

This study was a split-mouth clinical trial. To conduct the trial, 20 candidates were selected from among patients referring to Surgery Department of the Dentistry School at Yazd Shahid Sadoughi University of Medical Sciences for mandibular third molar removal surgery. The patients were divided into two groups after the surgery: one group received ibuprofen, and the other one received ketorolac. Pain, swelling, and trismus were evaluated prior to the surgical procedure, 24 hours later, and one week after the surgery. Data were analyzed by SPSS software version 22 by using Wilcoxon statistical tests and paired t test.

Ibuprofen and ketorolac had similar effects on pain relief (P value>0.05). Studying the two groups produced similar results regarding improvement in mouth opening (P value>0.05). Improvement pace of the postoperative swelling was significantly faster in the group receiving ketorolac compared to the one receiving ibuprofen (P value <0.05).

It was concluded that ibuprofen and ketorolac had positive and almost similar effects on pain control, edema, and trismus after molar surgery. However, ketorolac was more effective in controlling edema after surgery.

Many patients refer to their load implants while there is no attached gingiva in the area of prosthetic implants – unlike the attached gingivae found with natural teeth. The important role played by gingiva in comforting the patient and preventing gingival inflammation has not been fully appreciated yet. This study aimed to evaluate the association between the attached gingival height with gingival inflammation and patients’ comfort.

This retrospective cohort study was conducted to examine 80 implants (Dio uf) placed in 63 patients. At least two months had passed since the patients had had implant crown. The patients were divided into three groups: attached gingiva, gingival up to 2 mm, and at least 2 mm of attached gingiva. Indices such as bleeding on probing (BOP), the amount of plaque, gingival index and patient comfort during brushing and chewing were evaluated. Statistical data were analyzed using the Kolmogorov– Smirnov test, Levene’s test and independent t-test.

By increasing the height of attached gingiva, decreases were observed in probing depth (P value=0.004), BOP (P value=0.001), the degree of plaque index (P value=0.006), and gingival index (P value=0.003); and this association was statistically quite significant. By increasing the attached gingiva height, furthermore, the patients felt less discomfort when brushing and chewing; however, the findings were not statistically significant in terms of patients’ comfort during chewing (P value=0.364).

Increasing the height of attached gingiva reduced the symptoms of gingival inflammation, but increased patients’ comfort when chewing and brushing.

The need to replace new drug structures for the treatment of resistant strains has become essential. Streptococcus mutans is one of the most important factors in causing tooth decay. Glucan binding protein-C (Gbp-C) is a crucial mobileular floor protein that is worried in biofilm formation, and 1, 3, 4-oxadiazoles are new antibacterial structures. Accordingly, this study focused on assessing in vitro and in silico activity of our previously synthesized compounds of 1, 3, 4-oxadiazole against S. mutans.

To this end, our previously synthesized derivatives were re-synthesized and prepared, and then antibacterial susceptibility tests were used for inhibition zone, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) test values. The molecular docking method was also applied to confirm the effect of compounds in interaction with the Gbp-C of S. mutans.

All compounds showed different effects against the bacterial sample. Among these, the most effective ones were related to naphthalene (4d), fluorophenyl (4e), and dimethoxyphenyl (4h) derivatives against S. mutans, respectively. Other compounds also had antibacterial properties but to a lesser extent. In the molecular part, compounds 4d and 4h had the highest affinity to inhibit the GbpC-protein. compound 4d with amino acids ASP and GLN established 402 and 391 hydrogen bonds, respectively, and compound 4h with amino acids SER, GLU, THR, and TRP established 347, 360, 449, and 451 hydrogen bonds, respectively.

In general, 1, 3, 4-oxadiazoles containing naphthalene and dimethoxy phenyl functional groups in high concentrations can be good alternatives to the existing drugs for eliminating caries-causing tooth mutants that have drug resistance. It seems that more inhibitory effects can be observed on clinical specimens by adding different purposeful groups and increasing the destructive power of oxadiazole-based compounds.

The present report aimed to explore the case of an 8-year-old patient with chief complaint of the lack of eruption of the maxillary right permanent central incisor, referring to the Department of Pediatric Dentistry, Faculty of Dentistry, Hamadan University of Medical Sciences. The corresponding tooth on the contralateral side had fully erupted. The patient’s history revealed that the predecessor deciduous tooth had sustained a trauma, resulting in the partial intrusion of the tooth into the alveolar bone, that is, the relative intrusion of the deciduous central incisor. CBCT examinations were ordered for further evaluation, which showed the upward displacement of the permanent tooth bud in the alveolar bone as a result of the trauma, adhering to the floor of the nasal cavity. Therefore, root formation was halted, making the tooth embedded.