فهرست مطالب
Journal of Dental Materials and Techniques
Volume:8 Issue: 1, Winter 2019
- تاریخ انتشار: 1397/10/30
- تعداد عناوین: 8
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Pages 1-7Ridge atrophy accompanied by the pneumatization of maxillary sinus in the maxillary posterior region may lead to inadequate bone height, thereby precluding implant placement. Therefore, it may be mandatory to perform a sinus membrane elevation procedure and augmentation in the bone. The present study aimed to introduce a novel modification method for sinus floor elevation using a gelatin sponge (Gelatamp, COLTÈNE ROEKO, India) in order for better visualization, hemostasis, and conservative maxillary sinus membrane dissection with the low risk of complications. Implant placement was performed in a case series of 28 patients with hyperpneumatized sinus or a moderately resorbed posterior maxillary alveolus.
According to the findings, implant placement caused no complications in the patients. Furthermore, none of the patients experienced infections, sinusitis or graft and implant failure clinically and radiographically at the three- and six-month follow-up. Therefore, it could be concluded that gelatamp-assisted sinus lift is a simple, safe, noninvasive, and innovative technique for sinus membrane elevation. In addition, it is predictable and efficient, especially in the cases where piezoelectric surgery armamentarium is not available.
Keywords: Sinus Lift, Gelatin Sponge, Implant -
Pages 8-11Mutilation in the facial region may significantly affect the self-image and personality of individuals. Prosthetic rehabilitation of facial defects could increase the quality of life, thereby encouraging the patients to build up their self-confidence to return to normal social life. Acceptable cosmetic results are often obtained through facial prosthesis. Recovery after the loss of an eye requires proper adjustment to monocular vision and the improvement of appearance with an artificial eye, which is meticulously prepared to match the remaining natural eye. The present study aimed to demonstrate a technique for the fabrication of an ocular prosthesis with stock iris and custom-made sclera to provide aesthetically satisfactory results.Keywords: Ocular Prosthesis, Ocular Defect, Semi-customized Ocular Prosthesis, Phthisis Bulbi
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Pages 12-18IntroductionVarious surface treatments have been used to improve the adhesion of resin cement to zirconia restorations. The present study aimed to investigate the effects of different surface treatments on the bond strength of resin cement to zirconia (Y-TZP) in clinical practice.Methodsthirty square Y-TZP samples were classified into three groups of 10, including group SB (50 µm sandblasted Al2O3 particles), group B (diamond burs), and group C (control). One sample from each group was subjected to X-ray powder diffraction, scanning electron microscopy (SEM), and profilometer analysis. The shear bond strength (SBS) of zirconia-resin cement was measured using a universal testing machine at the crosshead speed of 1 mm/min until bonding failure. SBS values were analyzed using analysis of variance (ANOVA) and Tukey’s HSD test (α=0.05).ResultsAccording to the results of ANOVA, SBS was significantly affected by the treatment method. Tukey’s HSD test showed significant differences between the groups (P<0.05). Groups SB (9.99±0.78 MPa) and B (9.30±0.67 MPa) had significantly higher SBS values compared to group C (6.47±1.33 MPa) (P<0.05), while they had no significant differences with each other in this regard (P>0.05). In addition, SEM evaluations indicated morphological differences between the Y-TZP samples. According to the results of X-ray diffractometer, monoclinic phase transformation was observed in group SB only (28%).ConclusionAccording to the results, grinding and sandblasting were both effective in chairside surface treatments for improving the bond strength of the resin cement to Y-TZP. However, it should be considered that sandblasting may cause phase transformation.Keywords: Bond Strength, Chairside, Surface Treatment, Zirconia
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Pages 19-24IntroductionThere is currently significant interest in all-ceramic dental restorations. A potential non-metallic material for such restorations is an apatite-mullite glass-ceramic that could be processed to shape using different processing techniques. The aim of this study was to assess and evaluate the ability of an apatite-mullite glass-ceramic material to be processed using three routes: lost-wax casting, hot pressing and CAD-CAM milling.MethodsA batch of glass for an apatite-mullite glass-ceramic material was produced based on the formula (4.5SiO2-3Al2O3-1.5P2O5-3CaO-0.5 CaF 2). The batch was converted into glass by heating at 1050˚C/1450˚C for two hours. The final melt was quenched to obtain a glass frit. The glass was thermally treated based on the DTA data. The sequence of crystallization and their micro structural evaluation were analysed using X-ray diffraction (XRD) and scanning electron microscopy (SEM). An anatomically correct mould of an upper right first molar was selected to trial the three different manufacturing techniques. Empress II and VITA block mark II materials were used as control materials.ResultsThe apatite-mullite material being evaluated can be cast and milled to shape, but the ceramic form of the material is not capable of being hot pressed.ConclusionThe materials tested show great possibility as restorative materials and could be heat treated inside and outside the investment casting material to produce a crystalline microstructure of apatite and apatite-mullite. It is possible to produce acceptable restorations using the milling technique. Hot pressing the material is not recommended due to its high liquidus temperature.Keywords: Apatite-Mullite, Glass-Ceramic, Processing, CAD-CAM, Hot Pressing, Lost-Wax
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Pages 25-32IntroductionTemporomandibular joint (TMJ) disorders are among the most prevalent abnormalities of the jaw, which affect the masticatory system, including the muscles, TMJ, and tendons. Clinical examination alone cannot determine the cause of temporomandibular disorder (TMD). In most cases, the cause of TMD and a proper treatment plan are determined based on imaging modalities. The present study aimed to investigate
the bone changes in the patients with TMD symptoms using cone beam computed tomography (CBCT).MethodsThis retrospective, cross-sectional study was conducted through recording data on the pain caused by TMJ (upon touching, using the TMJ, and maximum mouth opening), clicking, and crepitus using a checklist of clinical symptoms. CBCT images were examined for the associated bone changes, including sclerosis, flattening, erosion, and osteophyte. Data analysis was performed in SPSS version 21 using Chi-square and logistic regression analysis.ResultsIn total, 160 joint images were examined, including 132 cases of flattening (82.5%), 45 cases of sclerosis (28.12%), 41 cases of osteophytes (25.62%), and 66 cases of erosion (41.25%). A significant association was observed between pain and flattening, and sclerosis and osteophytes. Moreover, a significant correlation was observed between flattening and clicking (P<0.05).ConclusionAccording to the results, flattening was the most common bone change in the patients with TMD. In addition, sclerosis had the most significant association with pain, while sclerosis, osteophytes, and erosion were significantly correlated with joint crepitation.Keywords: Temporomandibular joint, Cone Beam CT, Bone Changes -
Pages 33-38IntroductionThe school-based oral health programs are an opportunity to inspire positive attitudes and proper oral health behavior in students. The purpose of this study was to compare the effects of two oral health education methods on the oral health of boarding high school students in Fariman, Iran.MethodsIn this interventional study, 345 students were randomly divided into three groups, namely self-led (control), teacher-led (instructed by teachers), and peer-led (instructed by students). All students were subjected to Simplified Oral Hygiene Index (OHI-S), Gingival Index (GI), Plaque Index (PI) measurements before and three months after the intervention. The data were analyzed using the paired
t-test, the Kruskal-Wallis, and the Chi-square tests. The P-value less than 0.05 was considered to be significant.ResultsThe results of the study showed a significant decrease regarding the scores of all three indices (P<0.001) in the peer-led group, compared to the self-led intervention. According to the paired sample t-test analyses following the intervention, there was a significant decrease in the mean OHI-S , GI, and PI in all three groups (P<0.001), peer-led group (P<0.001), and peer-led and self-led groups (P<0.001), respectively.ConclusionDue to the significant decline in all three indices of the peer-led group compared to the other two groups, using talented students as “oral and dental health assistants” may be an effective approach for promotion of oral and dental hygiene among teenagers. However, there is aneed to conduct more research in this field of study.Keywords: Education, Student, Oral Health -
Pages 39-44IntroductionDental caries is the most common chronic condition in children. Recently, there has been a growing tendency to using digital panoramic radiography among clinicians. The present study aimed to determine the accuracy of digital panoramic radiography with and without software enhancement in the diagnosis of proximal dental caries in primary molars.MethodsThis study was conducted using 27 digital bitewings and panoramic radiography in 2016. Initially, panoramic radiography without enhancement was observed by a maxillofacial radiologist. Afterwards, sharpen, pseudocolor, emboss, and reverse-contrast enhancements were applied, and radiography was re-evaluated. In addition, bitewing radiography was investigated. After data collection, data analysis was performed in SPSS using the Kruskal-Wallis test and kappa coefficient agreement at 95% confidence interval.ResultsNo significant difference was observed between digital panoramic and bitewing radiography in the diagnosis of interproximal caries in primary molars. The maximum coefficient of agreement was obtained in maxillary and mandibular E (ƙ=0.893) and maxillary and mandibular D (ƙ=0.874 and ƙ=0.897, respectively). Moreover, no significant differences were denoted between the enhancement tools in the diagnosis of interproximal caries (P>0.05). In general, sharpen four was found to be the most powerful tool in this regard.ConclusionAccording to the results, digital panoramic imaging system was as accurate as bitewing radiography in the diagnosis of proximal dental caries. However, using enhancement tools in panoramic radiography was not helpful in the diagnosis of caries.
Keywords: Proximal Caries, Panoramic Radiography, Bitewing Radiography -
Pages 45-52IntroductionGlass ionomer cement (GIC) is a restorative material used in pediatric dentistry, which attaches to dental hard tissues and has cariostatic properties due to the ability for fluoride release. The present study aimed to assess the fluoride release and uptake capacity of two GICs in the presence of various fluoride sources.MethodsThis in-vitro study was conducted on 120 disks composed of two GICs (Fuji II LC, Equia Forte System), which were prepared with the exact dimensions of 5×2 millimeters. Fluoride release ability of the samples was determined every 24 hours for seven days and weekly (days 7-21) using a combination of ion selective electrodes. The samples in each group were divided into three subgroups and subjected to no fluoride treatment, fluoridated dentifrice (once a day for one minute), and MI Paste Plus (once a day for one minute). After recharging the samples for seven days, the level of fluoride release was measured on days 1-7, 14, and 21.ResultsThe results of one-way analysis of variance indicated that the fluoride release ability of Fuji II was higher compared to that of EQUIA Forte (P<0.001). In addition, fluoridated dentifrice could recharge both the glass ionomers more significantly than the MI Paste Plus.ConclusionAccording to the results, light-cured, resin-reinforced glass ionomers could release significantly higher levels of fluoride compared to EQUIA Forte. Moreover, the fluoride rerelease was higher by the GICs when recharged with fluoridated dentifrice compared to the MI Paste Plus.Keywords: Casein Phosphopeptide-Amorphous Calcium Fluoride Phosphate, Dentifrices, Fluoride, Glass Ionomer