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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  • Sahand Samieirad, Majid Eshghpour, Elahe Tohidi, Anahid Jouya, Rashid Soufizadeh*, Hamed Kermani Pages 1-7
    Ridge 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
  • Maru Kavita, Gangwal Archita, Barjatya Saurabh* , Dhalwani Bhumika Pages 8-11
    Mutilation 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
  • Elif Yein * Pages 12-18
    Introduction
    Various 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.
    Methods
    thirty 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).
    Results
    According 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%).
    Conclusion
    According 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
  • Hawa M Fathi* _Anthony Johnson Pages 19-24
    Introduction
    There 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.
    Methods
    A 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.
    Results
    The 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.
    Conclusion
    The 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
  • Fatemeh Hafez Maleki, Abbas Shokri, Seyyed Hossein Hosseini Zarch, Amirhossein Bahraniy, Alireza Ebrahimpour, Seyede Mona Alimohamadi* Pages 25-32
     
    Introduction
    Temporomandibular 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).
    Methods
    This 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.
    Results
    In 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).
    Conclusion
    According 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
  • Fatemeh Khorakian, Taraneh Movahhed, Zahra Mohammadzadeh* Pages 33-38
     
    Introduction
    The 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.
    Methods
    In 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.
    Results
    The 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.
    Conclusion
    Due 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
  • Somayeh Nemati, Seyedeh Tahereh Mohtavipour, Seyedeh Saeede Mohtavipour, Naghmeh Abdollahi* Pages 39-44
     
    Introduction
    Dental 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.
    Methods
    This 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.
    Results
    No 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.
    Conclusion
    According 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
  • Karim Jafari, Saleh Hoseini, Somayeh Hekmatfar* Pages 45-52
    Introduction
    Glass 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.
    Methods
    This 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.
    Results
    The 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.
    Conclusion
    According 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