Journal of Mashhad Dental School
Year:2016 | Volume:40 | Issue:3|Papers Count:11

Introduction: Halitosis is an unpleasant odor, smelled from one’s breath. This condition is in fact a widespread problem in the society. Halitosis can be due to several reasons. Therefore, this study aimed to evaluate Shiraz dentists’ knowledge of diagnosis and management of halitosis.Materials & Methods: A researcher-made questionnaire was distributed among 70 dentists, randomly selected from all the dentists in Shiraz, Iran. The research questionnaire consisted of 13 questions evaluating the knowledge of dentists of the causes (four items), diagnostic methods (five items) and treatment methods (four items) of halitosis.Results: Among the participants, 47.1% were male and 52.9% were female. Total mean knowledge score of the subjects was estimated at 10.56±1.92. In terms of causes of halitosis, mean knowledge score was 4.61±1.10, while it was 3.0±37.67 and 2.57±0.67 regarding the diagnostic and treatment methods of the mentioned condition, respectively. According to the results, a significant reverse correlation was observed between mean knowledge score of the subjects and variables of age and experience.Conclusion: In the present study, dentists’ knowledge of causes of halitosis, as well as diagnostic and treatment methods in this regard were evaluated, and the results were indicative of proper knowledge of dentists.

Introduction: Dental caries is an infectious disease and various microorganisms have a pivotal role in its onset and development. Medications used to reduce microbes are usually accompanied with side effects. Therefore, it seems necessary to search for antimicrobial agents with less side effects. In this study, we aimed to evaluate the antimicrobial effects of aqueous and alcoholic extracts of saffron on oral pathogenic microbes.Materials & Methods: In total, six 9-year-old male students were selected from a primary school. Samples of dental plaque, saliva, and depth of tooth decay were obtained from the participants to evaluate Streptococcus mutans, Lactobacillus, and Candida albicans and were sent to the laboratory afterwards. After assessing the samples via broth dilution method and incubation, six samples of Lactobacillus, eight samples of Candida albicans, and six samples of Streptococcus mutans were evaluated due to difficulty in turbidity detection. Afterwards, overnight cultures were prepared and evaluated for minimal bactericidal concentration (MBC) determination. In the next stage, penicillin and nystatin positive culture tests were used to compare the effects of microbes. In this study, one-way ANOVA was used to compare all the study groups, while pairwise comparison was performed using Tukey test.Results: Our findings were indicative of inhibitory effects of aqueous and alcoholic extracts of saffron on all three microbes. However, they were less effective compared to standard antibiotics (e.g., penicillin). A significant difference was observed between the effect of aqueous and alcoholic extracts of saffron and penicillin on the Streptococcus mutans (P<0.001). Similarly, a significant difference was found between the effects of saffron extracts and penicillin on the Lactobacillus (P<0.0001). Moreover, a significance difference was observed between extracts of saffron and nystatin on Candida albicans (P<0.001). According to the results, alcoholic extract of saffron was more successful in eliminating Candida albicans and Streptococcus Mutans, compared to aqueous extract of saffron (P<0.001).Conclusion: According to the results, while saffron had bacteriostatic effects on Streptococcus mutans and Lactobacillus, it had antifungal activities against Candida albicans. Therefore, saffron could be recommended as a mouthwash due to its herbal origin, cost-effectiveness, and fewer side effects.

Introduction: Root canal treatment could be associated with postoperative pain in patients. One of the leading causes of this pain is the extrusion of intracanal debris from the apical foramen during preparation and shaping. Among the common tools used in this regard are Race and Reciprocating files. Therefore, this study aimed to compare the intensity of postoperative pain using the mentioned systems.Materials & Methods: This randomized clinical trial was conducted on 90 mandibular molars, who were divided into two 45-case groups. Following that, the samples were cleaned and shaped using Race and/or Reciproc files. Pain intensity was demonstrated using a visual analogue scale on 4th, 12th, 24th, 48th, and 72nd hours, as well as the first week after surgery, followed by the comparison of the results of study groups. Data analysis was performed using independent sample t-test, chi-square/Fisher’s exact test, and repeated measures. P-value of less than 0.05 was considered statistically significant.Results: In the RaCe group mean pain intensity at 4, 12, 24, 48, and 72 hours and the first week after surgery was 32.89, 25.71, 22.69, 17.36, 11.24, and 1.00, respectively. These values were 33.51, 31.36, 26.80, 24.02, 20.11, and 2.04, in the Reciproc group, respectively. Pain intensity at different times was significantly lower in the RaCe group, compared to the Reciproc group (with the exception of the fourth hour and first week after surgery) (P<0.001).Conclusion: According to the results, use of Reciproc file during preparation and shaping of root canals in necrotized teeth was accompanied with less pain, compared to Race file. Therefore, it is recommended that this system be used in similar situations.

Introduction: Today, the use of all-ceramic restorations in dental implants has increased due to proper structural characteristics and excellent esthetics. For more beauty, zirconia frames might be exposed to repetitive firing cycles due to their unfavorable color, leading to increased lack of restoration compliance. Given the effects of marginal gap on inflammation around fixtures and implant failure, this study aimed to evaluate the effects of porcelain multiple firings on marginal gap and internal fit of zirconia frames to dental implant abutments.Materials & Methods: In total, 40 abutments were selected and divided into four groups. In the first group, zirconia frames were fabricated at 0.4 mm diameter. The frames were cemented and marginal gap was measured after thermal cycles (magnification: 40X). In addition, the space between the abutment and crown, which was cut with a diamond disc, was measured in order to measure internal fit values (magnification: 40X). While the phases were similarly carried out for the second, third, and fourth groups, the samples were porcelain-fused for two, four, and six times before cementing the implant crown to the abutment, respectively. Moreover, the final porcelain thickness was estimated to be 2 mm, followed by the evaluation of the marginal gap parameters and internal fit values.Results: In this study, the marginal gap value was reported to be 52-69 micrometers, while the internal fit value was 17-26 micrometers. In terms of marginal gap and internal fit of zirconia frames, no significant difference was observed in the samples after porcelain firing cycles, compared to those with no firing.Conclusion: According to the results, zirconia was not significantly affected by porcelain firing cycle due to its high mechanical properties, as well as high strength and complete sintering. Moreover, no significant difference was observed in the compliance of zirconia frames with dental implant abutments after multiple firing cycles.

Introduction: Currently, a substance called casein phosphopeptide-amorphous calcium phosphate has been used as a substitute for fluoride mouthwash. This study aimed to compare the remineralization rate of fluoridated GC tooth mousse with concomitant use of fluoride mouthwash and GC tooth mousse on demineralized enamel lesions.Materials & Methods: In this laboratory study, 50 samples were selected from 30 intact human premolars, halved into buccal and lingual segments, and randomly divided into five groups. Enamel health was recorded using a DIAGNOdent device and Vickers micro hardness test.Afterwards, the remineralized agents were applied to the surface of samples for two weeks as follows: 1) Control, 2) Fluoridated GC tooth mousse, 3) GC tooth mousse, 4) Sodium fluoride mouthwash and 5) Sodium fluoride mouthwash+GC tooth mousse. Repeatedly, enamel remineralization values were recorded via DIAGNOdent device, and data were analyzed using one-way and two-way repeated measures ANOVA tests.Results: Our findings indicated that no significant difference was observed between remineralization rate of fluoridated GC tooth mousse and concomitant use of fluoride mouthwash and GC tooth mousse, evaluated by DIAGNOdent device (P=0.959) and Vickers micro hardness test (P=0.884).Conclusion: According to the results, application of fluoridated GC tooth mousse with concomitant use of fluoride mouthwash and GC tooth mousse had a similar impact on remineralization of demineralized enamel lesions.

Introduction: Evidence suggests a successful use of autogenous bone grafts with or without a collagen membrane for lateral ridge augmentation. In this regard, one of the approaches is the use of sub periosteal tunneling technique to produce tent effect after flap designing and placing the collagen membrane. With regard to the lack of sufficient data on this technique, more accurate studied are needed. Furthermore, limited studies are available and complications, as well as the chance of treatment failure must be investigated. This convenient method could be a viable alternative to open techniques if provided with reasonable success.Materials & Methods: In this study, samples were among edentulous patients, who were candidate for implant and referred to School of Dentistry in Mashhad, Iran. The subjects were examined and their cone beam computed tomography (CBCT) was provided. In total, 10 patients with inadequate ridge width were enrolled in the study. Afterwards, sub periosteal tunneling technique was applied on the subjects using Cerabone or CenoBine for lateral augmentation treatment. The ridge width was evaluated after six months. Moreover, pain and swelling at the surgical site were evaluated at the first, suture removal and the last sessions. Data analysis was performed using one-sample t-test and two-way ANOVA.Results: T-test showed a significant increase in both group (Cerabone: 1.44±4.17, CenoBone: 0.64±1.25). The mean increase in Cerabone group was significantly higher than CenoBone group. No pain and swelling were observed.Conclusion: According to the results, the increase rate of bone width after six months in the group was significantly higher in the Cerabone group, compared to the CenoBone group.

Introduction: This study aimed to evaluate the shear bond strength (SBS) of silorane-based and methacrylate-based composites repaired by silorane-based composites after different surface treatments.Materials & Methods: In total, 32 composite cylinders were provided from each of the two composites types (e.g., P90: P and Z350: Z). Cylinders were allocated to four different groups as follows: no surface treatments (Z1 and P1), silane application (Z2, P2), erbium laser irradiation (Z3, P3) and sandblasting with alumina particles (Z4, P4). Afterwards, the bonding component of P90 adhesive system was applied to all the prepared composite surfaces, followed by the repairing of all the samples with P90 cylinders. Moreover, SBS of the repaired surface was evaluated using the universal testing machine (UTM). Data analysis was performed using the one-way analysis of variance (ANOVA) and Tukey HSD (honest significant difference) test (P£0.05).Results: In this study, the highest SBS values in each group (P and Z) were observed in the groups of P4 (40.23 MPA) and Z4 (51.19 MPA). However, the groups of P3 (20 MPA) and Z3 (46.16 MPA) obtained lower ranks. Silane application led to lower bond strength, compared to the other mentioned groups, and this difference was statistically significant (P<0.05). In addition, evaluation of the groups corresponding to two composites revealed a significant difference between the groups of Z4 and P4 (P=0.026).Conclusion: Silorane-based composites could be used to repair either methacrylate- or silorane-based composites by choosing proper surface treatments. In this study, while sandblasting and laser irradiation significantly improved bond strength of two composites, silane application indicated no such influence on bond strength.

Introduction: Milk is known as a healthy and nutritious snack, especially for children and adolescence. Development of new processes for the production of milk with a more favorable taste has led to increased consumption of flavored milk (chocolate), specifically in children. Caries formation potential of sweetened flavored milk and plain milk used by children has been the subject of many studies in the past. This study aimed to demonstrate whether chocolate milk can be a good substitute for plain milk regarding dental health or not.Materials & Methods: In total, 10 healthy dental students within the age range of 25-35 years were enrolled in the study after obtaining written informed consent. Inclusion criteria were the amount of salivary mutans streptococci and lactobacilli, saliva flow rate, no active caries in the mouth and no systemic diseases. Dental plaque pH was demonstrated in the interproximal areas between the second premolar and first molar in all four quadrants before and at two, five, 50, 40, 20, 15, 10 and 60 minutes after consumption (keeping in the mouth for two minutes and then swallowing) of three studied substances (e.g., chocolate milk, plain milk and 10% sucrose solution as positive control) via Metrohm microelectrode and digital pH meter. Afterwards, pH curve was illustrated according to the time of each tested product. Differences in maximum pH drops (DpH) after the consumption of evaluated materials were assessed by repeated measure ANOVA (P<0.05).Results: Plaque pH had been significantly decreased after the consumption of chocolate milk and 10% sucrose. While this reduction was more observed in the sucrose group, compared to chocolate milk, the latter led to higher decrease of plaque pH.Conclusion: Not only plain milk did not increase plaque pH more than basic pH at any time period, it significantly increased plaque pH at the majority of time intervals (e.g., 2, 5, 30, 40, 50 and 60) compared to basic plaque pH.

Introduction: Surface properties, including morphology, submicron and chemical morphology, are important factors affecting the quality and biological responses at the contact location of tissue with the implant material. This could significantly affect the healing process of bones.Materials & Methods: In this laboratory study, morphology and biocompatibility of polished mechanical nitinol (NiTi) shape memory alloys surfaces treated with mixed solution of three acids (HCl-HF-H3PO4) were evaluated. In the next stage, further chemical treatment was conducted in solution of HNO3 and HCl with ratio of 1: 1 Vol.% at room temperature and the results were assessed. Seventy-five samples were selected for chemical modification of the surface, biological evaluation and surface roughness; furthermore, nine samples were selected as control. Scanning the Electron Microscope (SEM), atomic force microscope (AFM) and inspection of Nitinol surface roughness (NiTi) were carried out to evaluate the surface. In addition, MG-63 cell was cultured on different nitinol surfaces to assess cell adhesion, growth and proliferation. Data analysis was performed using t-test and one-way ANOVA.Results: The obtained results indicated that HNO3 and HCl treatment produced significantly higher roughness compared to (HCl-HF-H3PO4) treatment and untreated surfaces. Moreover, evaluation of cell culture revealed significantly higher amounts of cell adhesion, growth and proliferation in two-stage modified nitinol surfaces, compared to the groups modified with triple acid solution and unmodified surfaces.Conclusion: According to the results, not only chemical surface modification of nitinol changed the surface morphology and created submicron roughness, but it also led to altered chemistry of the surface. This could increase bone-bonding ability in implant and decrease the toxic effects of nickel in the body.

Introduction: Generally observed in young children, dental avulsion is among the most serious dental injuries. If possible, immediate transplantation of the avulsed tooth is recommended as the treatment which usually leads to better prognosis.Case report: Two cases of delayed replantation of avulsed teeth were presented in this report. The first patient was a twenty-year-old male patient with a traumatic avulsed maxillary left lateral incisor occurring 20 hours prior to visit. Extraoral endodontic treatment, placement, repositioning, splinting and prescribing prophylactic antibiotic splint were carried out for our case during the first week. Splint was removed after six weeks. The second case was a sixteen-year-old boy with an avulsed maxillary right central incisor, which was kept in a dry place for 70 minutes and replanted in a different dental center. He was referred to us three days after the replantation. Splinting, root canal debridement and calcium hydroxide therapy were immediately performed at the first visit. Endodontic treatment was completed after four weeks, followed by the removal of the splint. Both teeth were in their functional position during the 1-year follow-up. Moreover, no radiographic or clinical symptoms of ankylosing were observed in the cases.Conclusion: According to the results, remaining in an extra-alveolar environment for an extended period (i.e., delayed replantation) might not affect the functionality of teeth in some cases.

Introduction: Palisaded encapsulated neuroma (PEN) is a rare benign neural tumor, often localized on faces and sometimes observed in a striking predilection on the skin of the face. This tumor might also occur in oral cavity, especially on the tongue. Some researchers have speculated that PEN is hamartomatosis, and there is a possible role of frequent trauma in its etiology.Case Report: Our case was a 27-year-old female with a painless flat swell in the right lingual mandibular gingiva. This lesion was formed about a year ago without any radiographic appearance. Fibroma and lipoma were included in the differential diagnosis of the lesion. Benign spindle cell tumor was reported in this reported according to histopathological examination results. Afterwards, immunohistochemical and silver stains were performed on desmin, S100, alpha-smooth muscle actin (a-SMA) and neuron-specific enolase markers for definitive diagnosis. The final diagnosis was PEN due to positive staining for S100 and NSE, as well as positive silver staining.Conclusion: According to the results, accurate diagnosis of PEN and differentiating it from other spindle cell tumors could help in the selection of the best treatment and prevention of unnecessary procedures.