Journal of Dentistry, Shiraz University of Medical Sciences
Volume:20 Issue: 2, Jun 2019

The dental adhesives may have the potential to increase the bond strength of orthodontic brackets to composite resin and it would be highly desirable if adequate bracket-composite bond strength could be yielded by using these adhesives without the need for surface roughening. The purpose of this study was to measure the shear bond strength (SBS) of metal brackets to composite restorations by use of a universal adhesive compared with a conventional adhesive. In this in vitro, experimental study, 45 composite discs measuring 6 mm in diameter and 4 mm in thickness were fabricated and assigned to three groups (n=15). In the group 1, discs were etched with 37% phosphoric acid for 15 seconds and Scotchbond Universal was then applied. Discs were roughened by diamond bur in the group 2 and were subjected to the application of Scotchbond Universal. In the group 3, conventional adhesive (Single Bond 2) was applied after roughening the discs by diamond bur. Metal brackets were then bonded to discs and after thermocycling, the SBS was measured by an Instron machine. The mode of failure and adhesive remnant index (ARI) score were determined using stereomicroscope. Data were analyzed by SPSS version 18, one-way ANOVA, and the Kruskal Wallis test. The surface roughening plus universal adhesive group showed the highest SBS (11.90 MPa) but according to one-way ANOVA, the difference in this regard among the three groups was not statistically significant (p= 0.94). Most samples showed ARI score of 4. Universal adhesive can provide sufficient bond strength as high as that provided by conventional adhesives for orthodontic bracket bonding to composite restorations even in absence of surface roughening by bur.

Prediabetic condition, which is characterized by impaired glucose tolerance, impaired fasting blood glucose, and hemoglobin A1c (HbA1c) higher than normal might be associated with periodontitis. Early diagnosis of this condition might decrease consequent tissue damage caused by periodontitis. The present study aimed to evaluate the association between prediabetes and periodontitis. This cross-sectional study was conducted on 108 prediabetic patients screened by primary fasting blood sugar (FBS) test (100-125 mg/dL). Three subsequent blood tests including FBS, HbA1C, and oral glucose tolerance test (GTT) were performed for ultimate diagnosis of these patients. The periodontal health was evaluated by employing bleeding on probing (BOP), clinical attachment loss (CAL), and plaque index (PI), Löe-Silness gingival index (GI), and pocket depth (PD). Data were analyzed by SPSS version 16, using t-test, ANOVA, and chi-square tests. The sample included 20 (19%) male and 88 (81%) female individuals with mean age of 49 years and mean BMI of 27.5. The mean FBS, GTT, and HbA1C were 107 MG/DL, 137MG/DL, and 5.9%, respectively. Clinical evaluation showed 33% of patients involved with periodontitis. The mean CAL, BOP, PI, PD, GI was 3.7, 0.62, 1.9, 2.1, 1.5, respectively (p< 0.05). A significant difference in periodontal index was found among patients with prediabetes. Moreover, in the patients with periodontitis, a statistically significant relationship between FBS and BMI, BOP and GTT, and finally between CAL and HbA1C was detected. Periodontitis is associated with prediabetic condition. While diabetes is an important risk factor for periodontitis, the risk of periodontitis would be greater if glycemic control is poor. Glycemic control in prediabetic patients can reduce the severity of periodontal disease. Early diagnosis and prevention is crucial to avoid the largely irreversible tissue damage that occurs in periodontitis.

Many studies have explored the prevalence of dental anomalies, with conflicting results, possibly attributed to differences in the ethnicities of the populations evaluated.  The aim of this study was to investigate the prevalence of dental anomalies, using panoramic images, in an Iranian population.  In this cross-sectional study, panoramic radiographs of patients aged 18 years or more, between 2015 and 2017 from three private clinics in Babol and Sari, were evaluated for presence or absence of anomalies (tooth shape, number, structure, and position). Data were analyzed using the chi square test, Student’s t-test, and analyses of variance. In this study, p ≤ 0.05 was considered significant.  Of 8018 cases examined, anomalies were found in 2250 cases (28.06%), with 95% confidence intervals of 27.08 - 29.0; one, two, and more than two types of anomalies were observed in 1968 (24.5%), 267 (3.3%), and 15 (0.2%) cases, respectively. Root dilaceration was the most prevalent anomaly (7.7%), followed by dens invaginatus (3.8%). Impaction was observed with a prevalence of 15.2%. Impaction, dens invaginatus, and missing teeth were significantly more prevalent in women than in men, whilst supernumerary teeth and hypercementosis were more common in men than in women (p< 0.05).  Regarding the relatively high prevalence of dental anomalies such as root dilacerations and dens invaginatus, it is essential to consider these anomalies carefully in treatment decision-making.

Effective and informed planning for orthodontic services in any population requires assessment of the orthodontic treatment need and complexity. The present cross-sectional study was conducted to assess these parameters using index of complexity, outcome, and need (ICON) in an Iranian schoolchildren population. In total, 600 randomly selected individuals (300 girls, 300 boys; aged 13-15 years) participated in this study. The treatment need (ICON score>43) and the grades of complexity were compared between two genders and in different age groups. Descriptive statistics and Chi-square test were applied for data analysis considering p< 0.05. Out of 45% of the population found in need for orthodontic treatment, there was no significant difference between the two genders, but the 15-year-old individuals needed treatment significantly more than the individuals with 13 and 14 years of age. The mean ICON score was 44.3±20.28, which showed no significant difference between the two genders. The majority of the cases (34%) were categorized in the easy compartment in terms of complexity and 18% had difficult or very difficult grades of complexity. The genders and age groups exhibited no significant difference in terms of the complexity grade. Although half of the studied cases needed treatment, nearly one-fifth had difficult or very difficult complexity grade, which indicates the need for specialist care.

Recently, zeolite has been regarded to improve the properties of dental materials such as mineral trioxide aggregate (MTA). The aim of the present study was to evaluate the effect of incorporating zeolite/silver/zinc (Ze/Ag/Zn) composite at 2 wt% to MTA powder on the push-out bond strength in simulated furcation perforations. Furcal perforations, measuring 1.3 mm in diameter and 2 mm in height, were simulated in 40 human mandibular first molars. The samples were allocated to two groups (n=20) based on the material used for the repair of perforations. In the group 1, MTA and in the group 2, MTA plus Ze/Ag/Zn (2%) was used. The samples were incubated at 37°C for 1 week. Then the universal testing machine was employed to measure bond strength. The resistance of materials to dislodgment was recorded in MPa. Data were analyzed using t-test. Statistical significance was set at p< 0.05. The push-out bond strength in the group 1 (6.40±1.98 MPa) was significantly higher than that in the group 2 (2.1±0.6 MPa) with p= 0.001. Under the limitations of the present study, it can be concluded that incorporation of Ze/Ag/Zn at 2 wt% to MTA powder had a negative effect on the push-out bond strength.

An oro-antral fistula (OAF) creates a passage for oral microbes into maxillary sinus with numerous possible complications. This retrospective study evaluates the success of three different surgical techniques of OAF repair. Records of patients that were treated for OAF repair were retrieved and reviewed. Data recorded were patients’ age, gender, etiology, size, location, duration, and method of repair. According to the surgical technique used to repair the OAF, patients were divided into three groups including buccal flap, palatal flap, and buccal fat pad. All of the patients were locally anesthetized with 2% lidocaine and 1/100000 or 1/80000 epinephrine. Then the edges of the fistula were excised and fistula wall was dissected in a stitched layer by three surgical methods. The three groups were compared concerning the success or failure of surgical technique based on complete closure of OAF after three months postoperatively. 147 patients (116 males and 31 females) with adequate records were included in the study. The surgical methods used in patients were, buccal flap in 59 (40.1%), buccal fat pad in 42 (40.8%), and palatal flap in 28 (19%) individuals. Success rates of these techniques were significantly different. Buccal fat pad was the most successful flap (98.3%), followed by buccal flap (89.8%), and palatal flap (85.7%). The most common cause of OAF in this group of patients was dental extraction. Buccal fat pad flap seems to be one of the best treatments for the closure of OAF lager than 5 mm.

Nonsuicidal self-inflicted injuries are socially unacceptable and may cause mild to severe damages. This study aimed to evaluate the demographic features of the subjects with orodental self-injuries referred to a forensic medicine center in Shiraz, Iran. This cross-sectional study evaluated 51 participants (49 men and 2 women) with orodental injuries referred to forensic medicine administration. Orodental self-injury was detected in the subjects, based on the last forensic criterion of self-injuries, considering their history, clinical examinations, and panoramic radiographs. The findings of this study revealed that dental self-injuries were more prevalent among married men from urban areas with secondary education levels. Most of the cases were due to the monetary compensation received. In the majority of cases, a hard object was used for this self-injury. Moreover, no statistical association was observed between the economic status and orodental self-injury. This study concluded that dental self-injury could be regarded as an unplanned incident because no significant correlation was observed between the participants, their economic status, and the type of dental trauma. Furthermore, detailed investigations on the latent variables are required.

Universal or multi-mode adhesives are new adhesive systems that can be used in both etch-and-rinse (ER) and self-etch (SE) modes. Lesser technical sensitivity and dual use of these adhesives have made them popular among dentists. Studies are being conducted to analyze the advantages and disadvantages these adhesives in different conditions The aim of this study was to compare shear bond strength (SBS) of a multi-mode adhesive in different etching modes to Er,Cr:YSGG laser ablated and bur-cut dentin. Buccal and lingual surfaces of 30 sound human molars, randomly divided to three groups, were prepared by bur and Er,Cr:YSGG (4 Watt and 5 Watt, 20 Hz, 96% water, 60% air, and 600-µm spot size) to reach a flat surface in superficial dentin. Each group was randomly divided into 2 subgroups (ER and SE), and then Scotchbond Universal adhesive was applied. Composite cylinders were attached to the surfaces and cured. Specimens were stored in 37 °C water for 24 hours and thermocycled (500 cycles) and were tested for SBS and failure modes were determined by stereomicroscope. Data was analyzed using SPSS19 and one- way ANOVA and Tukey’s post hoc tests and p< 0.05 was considered as significance level. Bur-cut dentin with ER method had the highest mean SBS value (33.80 MPa). SBS in bur-cut and 4Watt laser in ER mode were significantly higher than SE mode (p= 0.002 and p= 0.000 respectively). Highest mean SBS value in lased dentin was achieve in 4 Watt ER mode. SBS of Scotchbond universal adhesive to dentine is highest in bur-cut and ER mode and in 4-Watt lased-dentin is higher than 5-Watt lased-dentin. Moreover, in 4-Watt lased-dentin, SBS of ER mode is more than SE mode.

The clinical success of glass ionomer restorations depends on the strength of resin-modified glass ionomer (RMGI) cement bonding to dentin and there is limited information available regarding the bond strength of resin modified glass ionomers containing silica nanoparticles to dental structures. The aim of this study was to compare the microshear bond strength (µSBS) of RMGI with and without silica (SiO2) nanoparticles to dentin of permanent teeth. in this experimental study, the occlusal surfaces of 30 freshly extracted intact third molars were ground to expose the flat dentin and after conditioning with 20% poly acrylic acid, were randomly assigned to two main groups (n=15). The first group was filled with RMGI (Fuji II LC, GC) and the second group was filled with RMGI plus 0.5%wt. silica nanoparticles. Then, each main group was divided into three subgroups, and then stored in an incubator at 37 oC with 100% humidity for 1, 7, and 30 days. The µSBS test was performed using a universal testing machine (1 mm/min). The data were analyzed by t-test, repeated measures ANOVA and Tukey test (p< 0.05). There were no statistically significant differences between the mean µSBS of the groups with and without nanoparticles along the different storage periods (p> 0.05). There was significant difference in µSBS values among the three different storage periods in all the tested materials (p< 0.05). Incorporation of 0.5 %wt. silica nanoparticles did not compromise the µSBS of Fuji II LC RMGI to dentin.

Hybrid abutments are made of a titanium implant insert and a ceramic component. The tensile bond strength between the titanium implant insert and the ceramic component is not still clearly known. This in vitro study aimed to compare the tensile bond strength of the titanium insert to ceramic components made of milled lithium disilicate, milled zirconia, and pressable lithium disilicate. To standardize the shape and dimension of the ceramic components, a single computer-aided design/computer assisted manufacturing (CAD/CAM) superstructure was designed with Dental Designer software. Based on this model, CAD milled zirconia (Zr), CAD milled Lithium disilicate (CAD-LD) and heat-pressed lithium-disilicate (H-LD) superstructures were fabricated (n=10 per group). They were bonded to the titanium inserts by using self-adhesive resin cement. The prepared superstructure-titanium insert complexes (hybrid abutments) were screwed into the implants with 35 Ncm torque. The tensile bond strength of the ceramic superstructures to the titanium inserts were recorded by the universal testing machine with a crosshead speed of 2 mm/min. The data were analyzed by using one-way ANOVA and Tamhane post-hoc test (p< 0.05). The mean±SD of tensile bond strength was 328.50±30.4 N in CAD-LD, 257.30±23.8 N in H-LD, and 242.20±21.2 N in Zr groups. One-way ANOVA revealed the groups significantly different in terms of the tensile bond strength (p< 0.001). Tamhane post-hoc test showed a significant difference between the CAD-LD and the two other groups (p<0.001); however, no statistically significant difference was detected between the H-LD and Zr groups (p= 0.39). It can be concluded that the CAD-LD has higher bond strength to titanium insert compared with the H-LD and Zr groups. Therefore, they might be clinically more beneficial in high-esthetic areas.

Stem cells are considered as the principal source of differentiated cells. In the past few years, the research on the stem cell in various fields had shown success, but the stem cell-based therapies in the dentistry had confined to a particular extent. The present case report was aimed to evaluate the efficacy of stem cells from human exfoliated deciduous teeth (SHED) in the management of a large periapical lesion. A 12-year-old girl reported with a chief complaint of pain in the lower right back tooth region since 5 days. Intraoral examination revealed a deep occlusal cavity in relation to tooth#46 with tenderness on percussion. Radiograph examination revealed periapical radiolucency measuring 1.8×1.0cm in size with perforation at the floor of the pulp chamber in relation to 46. A deciduous tooth from the same child was collected to isolate stem cells. After access opening for tooth #46, pulp was extirpated and a thick mucoperiosteal flap was raised. This was followed by homing of SHED into the periapical area through the window created in the buccal cortical plate and into the root canals of tooth #46 until the orifice. The access cavity was sealed with glass ionomer cement. The patient was subjected to evaluation at regular intervals i.e., two weeks, four months, twelve months, and twenty-four months. The case treated demonstrated complete resolution of periapical radiolucency in the fourth-month review with a positive response to electric pulp testing. This clinical application report concludes that SHED can be effective in treating the periapical lesions in permanent teeth.

Transplantation and reposition of a tooth in its socket is relatively simple and predictable and can be considered as an alternative treatment option particularly in patients with financial limitation.This report describes a case of intra- alveolar transplantation of tooth #43 in a 35- year-old man. Clinical and radiographic examinations revealed tooth #43 with complicated crown-root fracture that had undergone endodontic treatment five months earlier. Reposition of mandibular bicuspid in its socket to re-establish biologic width and crown ferrule is an alternative treatment in cases with complicated crown-root fracture. Immediate replantation preserve viability of periodontal ligament cells and fibers attachment and good chance of healing is predicted.