فهرست مطالب

Dental Research, Dental Clinics, Dental Prospects - Volume:13 Issue: 1, 2019
  • Volume:13 Issue: 1, 2019
  • تاریخ انتشار: 1398/02/01
  • تعداد عناوین: 12
|
  • Saeed Rahimi, Sadegh Salarinasab, Negin Ghasemi, Reza Rahbarghazi, Shahriar Shahi, Amin Salemmilani, Baharak Divband, Paria Davoudi * Pages 3-10
    Background
     The aim of this in vitro study was to investigate the effect of zinc oxide (ZnO) and zirconium oxide (ZrO2) microparticles (MPs) and nanoparticles (NPs) in combination with white Portland cement (WPC) on odontogenic capacity of human dental pulp stem cells over a period of 21 days.
    Methods
    Synthesized ZnO and ZrO2 particles were characterized using scanning electron microscopy and transmission electron microscopy. The viability of human dental pulp stem cells was measured by a 3-(4,5-dimethylthiazolyl-2-yl)-2,5-diphenyltetrazolium bromide assay at 7-, 14- and 21-day intervals after seeding on WPC disks enriched with ZnO and ZrO2 MPs and NPs. Odontogenic potential of ZnO and ZrO2 particles in combination with WPC was investigated by alkaline phosphatase (ALP) activity and ionized calcium level of supernatant culture media at different time intervals. Data were analyzed using one-way ANOVA and post hoc Tukey tests.
    Results
    All the materials exhibited cell viability over a 21-day period, except for WPC with ZnO NPs on day 7, although it was not statistically significant (P>0.05). The ALP activity and ionized calcium level increased in all the groups compared to the control group (P<0.05). ZnO NPs had superior effect on odontogenic activity and calcium ion release compared to ZnO MPs (P=0.046). There was no significant difference between ZrO2 MPs and NPs in odontogenic activity (P>0.05).
    Conclusion
    WPC enriched with ZnO and ZrO2 increased ALP activity and calcium ion release of human dental pulp stem cells over a period of 21 days in vitro.
    Keywords: Human dental pulp stem cells, odontogenic differentiation, white Portland cement, zinc oxide nanoparti-cles, zirconium oxide nanoparticles
  • Seyed Amin Mousavi, Reza Ghotaslou, Abolfazl Akbarzadeh, Niloufar Azima, Ali Ayinfar, Azin Khorramdel* Pages 11-18
    Background
    Incorporation of antifungal and antimicrobial agents into tissue conditioners might inhibit the formation of microbial plaque and prevent complications such as denture stomatitis. The present study was carried out to evaluate the antibacterial and antifungal properties of a tissue conditioner after incorporation of ZnO‒Ag nanoparticles into their structure.
    Methods
    In this in vitro study, 4 microorganisms were evaluated at 6 concentrations of ZnO‒Ag nanoparticles at 24- and 48-hour intervals, using 168 samples. The nanoparticles were mixed at a ratio of 50% Ag and 50% ZnO and were homoge-nized with the tissue conditioner at 0.625, 1.25, 2.5, 5, 10 and 20 wt% according to the MIC technique principles. After culturing the microorganisms, a spectrophotometer was used for determining proliferation of microorganisms with the use of turbidity after 24 and 48 hours of incubation at 37ºC.
    Results
    Complete inhibition of the proliferation of Candida albicans, Enterococcus faecalis and Pseudomonas aeruginosa was observed at 24- and 48-hour intervals at a concentration of 10%; such inhibition was observed at 20% concentration of nanoparticles with Streptococcus mutans. In addition, the most effective concentration of ZnO‒Ag nanoparticles at both 24- and 48-hour intervals was 5% with C. albicans and 2.5% with E. faecalis. In addition, the most effective concentration at 24-hour interval with S. mutans was 10% and with P. aeruginosa they were 5% at 24-hour and 2.5% at 48-hour intervals.
    Conclusion
    Incorporation of ZnO‒Ag nanoparticles into tissue conditioners resulted in the inhibition of bacterial prolifera-tion.
    Keywords: Antibacterial, antifungal, tissue conditioner, ZnO‒Ag nanoparticles
  • Karim Jafari, Saeed Rahimzadeh, Somayeh Hekmatfar* Pages 19-23
    Background
    Mouthwashes are widely used as adjuncts to mechanical oral hygiene procedures. Nonetheless, there is little information regarding the effect of various mouthwashes on the amount of ions released from the nickel-chromium (Ni‒Cr) alloys used in the fabrication of fixed prostheses. Therefore, the present study was conducted to evaluate the effect of two types of mouthwash on the release of Ni ions from dental alloys.
    Methods
    Forty-two disk-shaped specimens were prepared with a diameter of 10 mm and a height of 2 mm. Two mouth-washes were examined in this study: Oral B and Listerine. A control group was also considered using distilled water. Each Ni‒Cr disk was immersed in the mouthwashes and distilled water in polypropylene test tubes, and then incubated at 37°C to simulate the oral temperature. After 45 days of incubation, the samples were tested for Ni ions using inductively coupled plasma mass spectroscopy. Data were analyzed using ANOVA.
    Results
    In the Halita group subjects exhibited 2.04±0.65 reduction in OLS. OLS reduction in the chlorhexidine group was 1.95±0.74. Statistical analysis showed no significant difference between the two groups (P>0.05).
    Conclusion
    As the results indicated, the amount of ion release was within the safe limits in the two experimental groups. However, it is recommended that prescribe Listerine mouthwash should not be prescribed for the patients with a history of Ni allergy.
    Keywords: Corrosion, dental alloys, nickel
  • Esin Bozdemir*, Hasan Hüseyin Yılmaz, Hikmet Orhan, Niloufar Azima, Ali Aienfar, Azin Khorramdel Pages 24-30
    Background
    The aim of this study was to determine the prevalence of oral lesions in terms of sex, age, educational status, medication use, systemic diseases, the duration of denture use and tobacco or alcohol use.
    Methods
    A total of 709 voluntary patients (375 males and 334 females), aged ≥60 years, were interviewed by one investi-gator for demographic data, systemic diseases, tobacco or alcohol use, denture use and the duration of denture use.
    Results
    The majority of the participants (87.6%) had one or more oral mucosal lesions. The prevalence of oral mucosal lesions was 46.3% in males and 41.3% in females (P=0.76). The most common oral mucosal lesion was a sublingual varicosity in both males and females. A statistically significant difference was observed between the three age groups (60–64, 65–69, and ≥70 years) with regard to the prevalence of oral mucosal lesions (P=0.02). There was a significant relationship between the presence of systemic diseases and oral mucosal lesions (P=0.01). There was also a significant relationship between denture use and oral mucosal lesions (P=0.001). Smoking and a history of smoking were also significant predictive factors for oral mucosal lesions (OR: 3.385, P=0.045).
    Conclusion
    Although the majority of oral mucosal lesions detected in the present study were benign, there were some patients with premalignant and malignant lesions. Therefore, periodic oral examinations for detection of precancerous and cancerous lesions are important, especially in the elderly, smokers and denture users.
    Keywords: Chronic disease, dentures, elderly, oral mucosa
  • Zahra Jamali, Mahdieh Alipour, Syamand Ebrahimi, Marzie Aghazadeh* Pages 31-35
    Background
    Halitosis (oral malodor) is a common problem all over the world and its prevalence has been estimated at 23‒50%. Halitosis originates from oral cavity in 85% of patients. This clinical trial was conducted to evaluate the efficacy of the Halita mouthwash in oral halitosis treatment.
    Methods
    Fifty subjects with an organoleptic score of >2 at baseline participated in this triple-blinded clinical trial. Subjects were divided into 2 groups. Group I subjects (N=25) were instructed to rinse with 0.2% chlorhexidine (CHX) mouthwash twice a day for 1 week. Group II subjects (N=25) used Halita mouthwash with the same instruction. Halitosis was evaluated at baseline and one week after using the mouthwashes by organoleptic method. Data were analyzed with chi-squared and Mann-Whitney U tests (P<0.05).
    Results
    In the Halita group subjects exhibited 2.04±0.65 reduction in OLS. OLS reduction in the chlorhexidine group was 1.95±0.74. Statistical analysis showed no significant difference between the two groups (P>0.05).
    Conclusion
    Based on the results, Halita mouthwash has the same effect on oral halitosis as routine 0.2% CHX mouthwash. Halita mouthwash has fewer side effects because of lower concentration of chlorhexidine. Therefore 0.2% CHX mouthwash could be replaced by Halita mouthwash for the treatment of halitosis.
    Keywords: 0.2% chlorhexidine mouthwash, clinical trial, Halita mouthwash, halitosis, organoleptic score (OLS)
  • Soodeh Tahmasbi, Seyedezahra Mousavi, Marjan Behroozibakhsh, Mohammadreza Badiee* Pages 36-42
    Background
    Enamel demineralization around orthodontic brackets is an important clinical problem. This study sought to compare the efficacy of sodium fluoride (NaF), casein phosphopeptide amorphous calcium phosphate fluoride (CPP-ACP-F; MI Paste Plus) and a water-based cream (Remin Pro), which contains hydroxyapatite and fluoride for prevention of enamel demineralization.
    Methods
    Fifty-six sound human premolars extracted for orthodontic purposes were collected. After cleaning, the crowns were mounted in acrylic resin and all the surfaces were coated with nail varnish except for a 3×4-mm window on the buccal surface. The samples were randomly divided into four groups of 14 and subjected to pH cycling for 14 days, during which the teeth were immersed in artificial saliva for 21 hours and in demineralizing agent for three hours daily. Before transferring the samples from the saliva to the demineralizing solution, the remineralizing agent (0.05% NaF, MI Paste Plus or Remin Pro Paste, depending on the group) was applied on the samples once a day for five minutes. No remineralizing agent was used in the control group. Surface microhardness of samples was measured by Vickers microhardness tester at baseline and after the intervention. The data were analyzed using one-way ANOVA, ANCOVA, Bonferroni test and Tukey test. Statistical sig-nificance was set at P<0.05.
    Results
    The mean microhardness was significantly different between the test and control groups (P<0.0001). Other differ-ences were not significantly different (P>0.05).
    Conclusion
    The results showed that 0.05% NaF was more efficient than Remin Pro and MI Paste Plus for prevention of white spot lesions (WSLs). Remin Pro and MI Paste Plus were not significantly difference from the control group in this regard.
    Keywords: Dental caries, fluorides, orthodontics, tooth demineralization
  • Arian Hesam Arefi, Hoda Shamsaddin, Mojgan Balvardi, Hamidreza Poureslami*, Masumeh Danesh, Mahsa Sayadizadeh Pages 43-50
    Background
    Severe early childhood caries (S-ECC) is a rapid form of dental caries that firstly affects primary upper incisors of children less <3 years of age and can cause interference in child’s health by pain, nutritional deficiencies and sleep disor-ders. It seems there are many unknown factors in the etiology as well as progression of S-ECC. The aim of this study was to assess parents' views in this relation.
    Methods
    In this qualitative study parent’s views and their 1‒3-year-old children were studied when they visited pediatric medical clinics in Kerman. After cleaning the children teeth and examination of them to discover caries, they were placed in 2 groups with or without S-ECC. Then each parent was interviewed separately and their comments were collected and studied. Examinations and interviews continued with parents until they did not express anything new.
    Results
    Parents of children without S-ECC had better understanding about S-ECC related factors than parents of children with S-ECC and greater number of them (without significant differences) expressed known reasons for occurrence of S-ECC. There were differences among known reasons and proposed reasons mostly in parents of children with S-ECC, although the differences were not significant. Maternal stress and amount of breast milk’s lactose were factors that were reported by some parents while there were unknown factors related to the etiology of S-ECC. Furthermore, no parents mentioned factors like saliva or mode of delivery.
    Conclusion
    The most important achievement of the study was the attention of some parents to the role of their chronic stress in the occurrence of S-ECC. Another important consideration was that none of the parents mentioned the important role of the quality and quantity of saliva in preventing S-ECC, which should be promoted in the community.
    Keywords: Breast milk lactose, early childhood carries, maternal stress, mode of delivery, qualitative study
  • Shabnam Khalifehzadeh, Sina Haghanifar, Niloofar Jenabian*, Sohrab Kazemi, Mahmoud Hajiahmadi Pages 51-56
    Background
    The ultimate aim of periodontal treatment is to regenerate periodontium and regenerative treatment after that. The aim of this study was to evaluate the effect of PRGF with 1% metformin biofilm in the treatment of two-wall intrabony periodontal defects.
    Methods
    In this clinical trial, 8 patients with moderate chronic periodontitis and two-wall intrabony defect were selected. The defects were assigned to 4 groups: debridement, 1% metformin, PRGF, PRGF and metformin. The parameters of vertical probing depth, vertical clinical attachment level and gingival index were measured at baseline, immediately before surgery, and 3 and 6 months after surgery. In addition, the radiographic changes were evaluated with digital subtraction radiography before and 6 months after surgery. Analysis of the results was performed with repeated measurements, Friedman test and chi-squared test.
    Results
    All the groups exhibited improvements in all the clinical parameters after 6 months. Inter-group comparison of GI, CAL and PPD parameters revealed no statistically significant differences. Radiographic changes in the group of 1% metfor-min with PRGF revealed statistically significant differences compared with other groups; however, there were no statistically significant differences in other groups.
    Conclusion
    Application of PRGF with 1% metformin in intrabony two-wall periodontal defects was effective in improving the clinical parameters but this effect revealed no difference compared with other groups; however, in terms of radiographic changes significant improvements were noted.
    Keywords: Intrabony two-wall periodontal defects, Metformin 1%, plasma rich in growth factor, regeneration
  • Damla Özsu Kırıcı*, Ertuğrul Karataş, Ahmet Demirhan Uygun, Ezgi Doğanay Yıldız, Kezban Meltem Çolak, Hakan Arslan Pages 57-60
    Background
    The aim of the present study was to compare the cyclic fatigue resistance of novel nickel titanium rotary path-finding instruments.
    Methods
    Twenty instruments were selected for each file system. A simulated stainless steel root canal, with a 90° angle of curvature and a curvature radius of 3 mm, was used for cyclic fatigue test of the ProGlider (#16, progressive taper: 0.02‒0.085), PathGlider (#15, taper: .03), and One G (#14, taper: .03) instruments. Statistical analyses were performed with one-way ANOVA (P=0.05). Post hoc Tukey tests were used to determine any statistically significant differences between the groups.
    Results
    The ProGlider instruments exhibited significantly more cyclic fatigue resistance than both PathGlider and One G instruments (P<0.001). One G instruments had significantly more resistance to fracture than PathGlider instruments (P<0.05).
    Conclusion
    ProGlider instruments had better cyclic fatigue resistance than PathGlider and One G instruments.
    Keywords: Cyclic fatigue, ProGlider, PathGlider, One G
  • Mehdi Daneshpooy, Fatemeh Pournaghi azar, Parnian Alizade Oskoee, Mahmoud Bahari, Saeede Asdagh, Seyed Reza Khosravani* Pages 61-67
    Background
    The current study aimed at identifying the color agreement between try-in pastes and the respective resin cements and investigated the effect of thickness and regions of Ultra-Translucent Multilayered Zirconia Veneers.
    Methods
    A total of 90 cubic zirconia discs were prepared at two different thicknesses (0.5 mm and 0.7 mm) (n=45) in five groups in terms of the shade of the try-in paste and resin cement as follows: Universal, Clear, Brown, White and Opaque. Try-in paste and the respective resin cement were applied between the specimens and composite substrate, respectively, and colorimetric evaluation was carried out using CIE-Lab system. For each specimen, ΔE between the try-in paste and cement was calculated. Data were analyzed with SPSS 17 using Multifactor ANOVA (P<0.05).
    Results
    Multifactor ANOVA results showed that ΔE values were significantly affected by the resin cement shade and the thickness of ceramic veneer (P<0.05). The results showed better shade agreement between the try-in paste and the respective resin cement with thicker ceramic veneers. The results of Tukey HSD revealed that ΔE values for the Clear, Universal and Brown shades were less than those of the White and Opaque shades. Lighter shades exhibited better agreement between the try-in paste and the respective resin cement.
    Conclusion
    Perceptible color difference was found between the try-in pastes and the respective resin cement in most colors investigated. Although, the agreement of the try-in pastes and the respective resin cement was affected by the thickness of zirconia veneers, the different regions of multilayered ultra-translucent zirconia ceramic showed no significant effect.
    Keywords: Color agreement, resin cement, try-in paste, ultra-translucent zirconia, veneer
  • Farhad Tabatabaian*, Khotan Aflatoonian, Mahshid Namdari Pages 68-74
    Background
    Effects of veneering porcelain thickness and background shade on the shade match of zirconia-based restora-tions are unclear. The aim of this study was to evaluate the impacts of veneering porcelain thickness and background shade on the shade match of zirconia-based restorations.
    Methods
    Forty A2 shade veneered zirconia disk specimens (10 mm in diameter) were fabricated, with veneering porcelain thicknesses of 1.6, 1.8, 2.0 and 2.2 mm. Three backgrounds were made of A2 shade composite resin (A2), nickel-chromium alloy (NC) and amalgam (AM). The veneered zirconia specimens were placed on the backgrounds. CIELab values were measured with a spectrophotometer. ΔE values were measured to determine color differences between the specimens and the A2 VITA classical shade (target shade). ΔE values were compared with an acceptability threshold (ΔE=3.7). Repeated measures ANOVA, Bonferroni, and 1-sample t-test were used to analyze data (P<0.05).
    Results
    Mean ΔE values ranged between 1.9 and 5.0. The veneering porcelain thickness, the background shade and their interaction affected the ΔE (P<0.0001). The minimum veneering porcelain thickness for the shade match was 2 mm for NC and 1.8 mm for AM.
    Conclusion
    Veneering porcelain thickness and background shade affected the shade match of zirconia-based restorations. With dark-shaded backgrounds, the amount of veneering porcelain thickness needed for the shade match might be beyond acceptable clinical limits. Tooth-shaded backgrounds are esthetically advocated rather than dark-shaded backgrounds in zir-conia-based restorations.
    Keywords: Ceramic, esthetics, shade, spectrophotometry, zirconia
  • Aydin Sohrabi, Shabnam Tahamtan*, Ali Rafighi, Seyed Hossein Moslemzadeh, Sana Seyed shariatdoost Pages 75-81
    Background
    The aim of this longitudinal observational study was to evaluate patients’ perceptions of alignment changes during the first stage of fixed orthodontic treatment.
    Methods
    Ninety-three non-extraction patients (mean age: 17.6 years) who were scheduled to undergo fixed-appliance treat-ment in the first author's private office were included. Patients assessed the alignment of their teeth subjectively using visual analogue scale at the bonding session and four, eight and 12 weeks later. The amount of Little's irregularity index at each session was calculated on stone casts. Freidman test was used to compare the “alignment changes” between different intervals. Correlation coefficients were calculated using Spearman test between Little’s irregularity indices and alignment scores re-ported by the patients in each session.
    Results
    No patients reported regression in alignment changes during three-month course of treatment. The final changes (from bonding session to the 12th-week visit) were smaller than the sum of the three intervals, which indicated that patients became more perceptive as the treatment progressed. Comparison of two scores reported for each session (in the same session and in the next session) revealed that patients could not recall their previous situation well. Patients do not perceive alignment changes in the same way as clinicians. Furthermore, patients who were 16 or older perceived smaller alignment changes during the first four-week period and smaller final alignment changes.
    Conclusion
    To obtain better patient compliance and improve their motivation throughout orthodontic treatment, patient-specific measures should be undertaken, including reminding them about their initial conditions and highlighting the changes as the treatment progresses.
    Keywords: Alignment, orthodontic treatment, tooth alignment