The Saudi Journal for Dental Research最新文献

Objective

Bioglass can be used as a non-invasive remineralizing treatment for enamel white spot lesions (WSLs). Cold plasma application can boost enamel surface properties by increasing its surface energy and wettability without disturbing the bulk structure or raising up pulp temperature. It is thought that the remineralizing ability of bioglass, might be enhanced if proceeded by plasma application. This study investigated the combined effect of cold plasma and bioglass on demineralized enamel.

Methods

Forty bovine incisors were sectioned to obtain flat enamel specimens and challenged by demineralization solution of pH 4.47 for 72 h. The enamel specimens were randomly divided into four groups: (I) control, demineralized enamel with no treatment (C); (II) demineralized enamel primarily treated with cold plasma, then bioglass paste protected with adhesive, afterward additional application of cold plasma (PBP); (III) demineralized enamel treated with cold plasma, then bioglass paste protected with light cured adhesive (PB); and (IV) bioglass paste applied to demineralized enamel and protected with light cured adhesive (B). All groups were stored in remineralizing solution for 24 h, subsequently cross-sectional micro-hardness measurements were done and then a scanning electron microscope (SEM) coupled with energy dispersive X-ray spectroscope (EDS) were used to examine specimen’s surface morphology and chemical analysis.

Results

Group II (PBP) showed a significant higher cross sectional micro-hardness value than bioglass group at 30 μm depth. SEM revealed numerous surface deposits of spheroidal and prismatic shape, EDS showed that the elements are mainly calcium, phosphorus with trace amount of silica and sodium.

Conclusion

Combined plasma/bioglass/plasma treatment could improve the remineralization of enamel white spot lesions.

Objective: The purpose of this study was to determine the accuracy and time taken to perform the space analysis (arch length discrepancy and Bolton’s) based on the severity of crowding using new virtual model software (3Shape Ortho System, 3Shape A/S, Copenhagen) with that of conventional plaster models. Materials and methods: Models from 45 patients, divided into three groups based on the severity of crowding (group 1: <2.5 mm, group 2: 2.5–5 mm, and group 3: >5 mm) were included in this study. The mesiodistal width of each tooth from first molar to first molar was measured to the nearest 0.1 mm with digital calipers, and the arch length tooth mass discrepancy and Bolton’s ratio were calculated for each model of every group. The total time required to perform the space analysis was recorded in seconds using a stopwatch. This process was repeated to record the digital measurements with the 3Shape Ortho System software. The difference between the two methods in all the three groups was calculated, and a paired t test was used to analyze the data. Results: The results showed no statistically significant difference between the mesiodistal width measurements, arch length discrepancy and Bolton’s values in all the three groups. However, the total time required to perform the space analysis between the two methods revealed statistically significant differences, with digital models averaging more time in all the groups. Conclusion: Virtual models can be used as an alternative to routine plaster models in model analysis procedures, independent of severity of crowding.

Objective

The purpose of this study was to assess the effect of platelet-rich fibrin (PRF) on postoperative pain, analgesic consumption, soft tissue healing and socket complications following the extraction of mandibular third molars.

Methods

A total number of 50 impacted third molars were surgically removed from 47 patients (13 males and 34 females; with a mean age of 25.24 ± 7.04 years). PRF clots were placed in the extraction sockets of patients included in the study group, while the sockets remained empty in the control group. The variables assessed were pain, analgesic consumption, soft tissue healing and socket complications encountered during the first postoperative week.

Results

In the study group, a significantly less pain was recorded in the fifth, sixth and seventh postoperative days (P = 0.041, 0.031 and 0.005 respectively). Patients included in the study group also significantly consumed less analgesics for the second, third, sixth and seventh postoperative days (P = 0.019, 0.039, 0.045 and 0.020 respectively). PRF significantly reduced the incidence of alveolar osteitis (P = 0.037) but not the infected or inflamed sockets (P = 1.00 and 0.312 respectively). No significant difference was observed between PRF and control groups regarding soft tissue healing (P = 0.187).

Conclusion

PRF could reduce alveolar osteitis, pain, and analgesic consumption following removal of impacted mandibular third molars.

Background: Extracted human teeth were suggested as a source for autogenous bone grafts, especially that they have similar chemical composition to bone. In order to accelerate healing of bone graft over the bony defect, numerous techniques utilizing platelet and fibrinogen concentrations have been introduced in the literature. Objectives: To evaluate clinically and radiographically the use of autogenous tooth bone graft material in combination with injectable platelet-rich fibrin for reconstruction of resorbed maxillary alveolar ridge. Patients and methods: This study was conducted in ten patients indicated for extraction of maxillary anterior or premolar teeth and having maxillary ridge deficiency. Implants were placed after a period of 3 months of bone grafting. The patients were selected from those attending the Oral and Maxillofacial Surgery Department, Faculty of Dentistry, Alexandria University. Results: Clinically, all the patients showed uneventful healing. Radiographically, the results show 30% increase in mean bone density in the period of six months when compared to pre-operative readings. The grafted site showed an increase in the mean volume by 23.47% three months post-operative when compared to the base line measurements preoperatively. Radiographic evaluation of the alveolar ridge after 3 months of grafting showed a significant mean increase in the ridge width and height at the grafted site. Conclusion: Autogenous fresh demineralized tooth graft that is prepared at the chairside after extractions could be considered as the gold standard for socket preservation, bone augmentation in sinuses or filling bone defects, in patients having non restorable teeth indicated for extraction. The adjuvant use of injectable PRF with its high growth factor content may contribute to more favorable and predictable bone formation at the grafted site.

The aim of this study was to evaluate the microtensile bond strength (μTBS) to dentin of an elective etching adhesive system applied in etch-and-rinse (ER) or self-etching (SE) mode after 6-months of storage in water. Thirty-six caries-free, human third molars were collected and stored in a 0.1% thymol solution. Dentin surfaces were exposed by 600-grit silicon carbide paper and teeth were divided into six groups (n = 6), according to the adhesive systems: a 2-step SE system, Clearfil SE Bond (CSE); a 1-step SE adhesive Adper Prompt L-Pop (LPOP); Scotchbond Universal applied as a 1-step SE adhesive (SBU-SE) and applied as a 2-step ER adhesive (SBU-ER); and two 2-step ER adhesives: Adper Single Bond Plus (SBP) and Optibond Solo Plus (OSP). Composite build-ups were constructed with TPH3 and cured in three increments of 2 mm each. Specimens were sectioned with a slow-speed diamond saw under water in X and Y directions to obtain bonded beams that were tested to failure in tension at a crosshead speed of 1.0 mm/min after one week or 6 months of storage in water. Statistical analyses were computed using Repeated-Measures ANOVA and Fisher’s LSD Tests (α = 0.05). There were no significant differences between 1-week and 6-months. SBU-ER and SBUSE showed the highest μTBS values and statistically differed from LPOP (Fisher’s LSD). The SBP, OSP, and CSE groups showed intermediary μTBS and did not differ statistically from SBU-ER, SBUSE or LPOP, which presented the lowest μTBS values. The use of elective etching adhesive system in dentin with the etch-and-rinse or self-etching approach did not compromise the bond strength and showed stable bonds after six months of storage in water.

Aim

This study was conducted to evaluate knowledge, attitudes, and practices regarding infection control measures among dental students at the College of Dentistry, King Saud University, Riyadh, Saudi Arabia.

Methods

A self-administrated English-language questionnaire with questions related to hepatitis B vaccination and serology, the use of personal protective equipment, infection control practices and awareness, percutaneous and mucous membrane exposure, and attitudes toward the dental treatment of infected patients was distributed to third-fifth-year dental students. Responses were analyzed using SPSS, with a significance level of p < 0.05.

Results

The response rate was 83.4% (n = 303). Most (95.4%) students had received hepatitis B virus vaccination, but only 61.4% had completed the three doses, with a significant difference among academic years (p = 0.000). Almost all students always used gloves (99.3%), masks (98.7%), and gowns (95%) while treating patients. Fewer students always used face shields (69.6%) and head caps (65%), with significant differences between males and females. About two-thirds (65%) of participants reported injury with a used instrument; such injury was significantly more common among fifth-year students (p = 0.041). The most frequently reported injuries were caused by needles and burs (21.1%). Male students were significantly more willing than female students to treat patients with infectious diseases.

Conclusion

The dental students surveyed in this study showed satisfactory knowledge and positive attitudes regarding infection control. More effort is needed to provide proper training in ideal infection control measures for undergraduate students.