Journal of Dentistry, Shiraz University of Medical Sciences
Volume:24 Issue: 3, Sep 2023

Sodium lauryl sulfate (SLS) is an anionic surfactant, which has a wide range of usage in the health sector and in dental pharmaceutical products, especially in toothpastes. The objective of this review was to investigate the effects of SLS containing dentifrices on oral and periodontal health, possible side effects, and its benefits. A thorough literature search was done using databases of PubMed and Google Scholar and finally, 40 articles were included in the study. This narrative review revealed the sources of discrepancy and conflicting results regarding the impact of SLS on oral cavity as well as a lack of sufficient evidence in most topics. Hence, the evidence suggests improved drug bioavailability when used as a solubilizer, improved plaque control, and reduction in bad breath. On the other hand, SLS can serve as a risk indicator of prolonged oral wound healing time, recurrent aphthous stomatitis.

Recurrent aphthous stomatitis (RAS) has been identified as a common oral lesion with an unknown pathogenesis. Various studies have been conducted to show the important role of two factors named epidermal growth factor (EGF) and vascular endothelial growth factor (VEGF) in RAS, but certain results have not been achieved. The present meta-analysis was conducted to evaluate the salivary levels of EGF and VEGF in patients with RAS. For this purpose, the related articles in the Web of Science, PubMed, Embase, ProQuest and Scopus databases until January 2022 were searched and their abstracts were studied. Google scholar and scientific information database were also searched for articles in Persian. The searches were completed by the medical subject heading terms considering "recurrent aphthous stomatitis" and "saliva" in combination with "EGF" or "VEGF" keywords. All case control studies that evaluated the salivary levels of EGF and VEGF in patients with RAS were included in this study. To evaluate statistical heterogeneity between the studies, Cochrane Q and I2 tests were adopted. The extracted data then were used in the analysis process based on comprehensive meta-analysis software. Originally, 619 articles were considered, of which 7 articles were selected. According to this meta-analysis, salivary EGF and VEGF levels were significantly lower in the active and remission period of RAS than in healthy individuals (p Value< 0.05). In addition, salivary levels of these factors were significantly lower in the active stage of RAS than in the healing phase. This review study suggests that decreasing of salivary EGF and VEGF levels have significant role in the development of RAS.

Statement of the Problem:

 It is important to use orthodontic composites with favorable properties, which are easily removed after the end of the treatment but not easily debonded during treatment. Nanoparticles have drawn attention for their antibacterial properties when added to composite resins. However, the effect of addition of nanoparticle on shear bond strength is not broadly discussed.

The present study was designed to compare the shear bond strength of orthodontic brackets bonded by orthodontic composite containing silver nanoparticles with orthodontic composite containing amorphous tricalcium phosphate nanoparticles.

In this ex vivo study, 36 sound extracted human premolars were used and randomly divided into three groups. The brackets were bonded in the first group by composite without nanoparticles, in the second group by composite containing 3% amorphous tricalcium phosphate nanoparticles and in the third group by composite containing 0.3% silver nanoparticles at the buccal surface of the teeth. The shear bond strengths of the samples were measured 24 hours after preparation by a universal testing machine. Data were analyzed using SPSS 21 software through one-way ANOVA and Tamhane's T2 multiple comparison tests. p Values under 0.05 were considered significant.

There was no significant difference between the mean shear bond strength of composite containing amorphous tricalcium phosphate nanoparticles with composite without nanoparticles (p= 0.142). However, the mean shear bond strength in the composite containing silver nanoparticles was significantly lower than the other two groups (p<  0.001).

According to the results of this study, the addition of amorphous tricalcium phosphate nanoparticles to orthodontic composite does not significantly decrease the shear bond strength while silver nanoparticles reduce the shear bond strength of orthodontic composite.

Statement of the Problem: 

Surface roughness of zirconia is an important parameter that determines the success of zirconia restorations. When zirconia surfaces are left rough, higher susceptibility to hydrothermal aging, plaque accumulation and color changes would occur. Therefore, polish retention of these restorations is considered as a challenge.

The purpose of this in vitro study was to determine the effect of hydrothermal degradation, pH- cycling, and simulated tooth brushing on surface roughness, topography, and polish retention of an yttrium-stabilized monolithic zirconia.

In this experimental study, 64 specimens of yttria-stabilized tetragonal zirconium oxide (20×4×2mm) were prepared (ZirKonzahn, Steger, Ahrntal). The specimens were wet- polished (standard polishing), and divided into 8 groups (n=8). Four control groups were assessed in non-aged condition while in 4 experimental groups the artificially ageing was done. Different finishing and polishing procedures were performed in 8 groups. The surface roughness values including mean surface roughness (Ra) and mean height of surface roughness (Rz) was measured by a profilometer. The results were analyzed using two-way ANOVA and Tukey’s HSD test (α=0.05). One representative specimen of each group was inspected under a scanning electron microscope (SEM) for assessment of surface topography.

The effects of surface treatments on Ra (p<.001) and Rz (p<.001) parameters were significant. Ageing had no significant effect on Ra (p=.086) and Rz (p=.067) values. Maximum Ra and Rz parameters were recorded following grinding (p<.001) and minimum values were recorded after glazing, which were significantly lower than the values in grinding group (p<.001). Polishing and glazing diminished the surface roughness (Ra) of ground zirconia similarly (p=.995).

Aging had no significant effect on surface roughness of zirconia, irrespective of surface treatment type. Grinding yielded maximum surface roughness. Intra oral polishing yielded a surface roughness comparable to standard polishing and glazing.

Statement of the Problem:

 The occurrence of papillary defects adjacent to teeth or dental implants causes both the dental staff and the patients to be concerned about the esthetic issues. Interdental papilla reconstruction surgery is one of the most difficult and unpredictable mucogingival surgeries.

The present study aimed to investigate the efficacy of hyaluronic acid injection in the reconstruction of the interdental papilla.

This clinical trial study was conducted on four patients with 20 deficient interdental papillae who met the inclusion criteria. At first, local anesthesia was applied. Afterward, 0.2 mL of 1.6% hyaluronic acid (HA) gel was injected (at the tip of the papilla and 2-3 mm below the tip of the papilla) three times every two weeks. At baseline, three, and six months later, clinical photography was taken under standard conditions. The papilla height (the distance between the interdental papilla tip and the basis), black triangle area, and the distance between the interdental papilla tip and contact point of adjacent teeth were all measured using Image J software.

The effectiveness of using HA gel in reducing the black triangle area was 85.06%. Furthermore, the papilla length increased by 70.256% while contact to papilla distance decreased by 83.026%. At different times, the values of the studied variables in the three levels were significantly different (p< 0.05).

Injection of HA with 1.6% concentration at two points of the interdental papilla was effective in interdental papilla reconstruction at the aesthetic zone, especially in long-term, follow-ups (especially 6 months).

Statement of the Problem:

 It is stated that engine-driven instruments might cause dentinal defects during root canal preparation. These defects might spread and progress into greater fractures or vertical root fracture.

This study aimed to compare the incidence of dentinal defects that might arise all through preparation of root canals, using One Shape, RaCe, and WaveOne systems in canals with a curvature (0-20°) and (20-40°).

In this in vitro study, 150 mandibular first molars were enrolled. Based on the degree of curvature in the mesial roots, the samples were divided into two groups (n=75) of straight and moderately curved canals (0-20º), and severely curved canals (20-40°). Then each group was randomly divided into four sub-groups. In subgroups 1 to 3 from each group, canals were prepared using WaveOne, One Shape, and RaCe. Then all roots were sectioned at 3, 6 and 9-mm distances from the apex. The slices were evaluated using stereomicroscope at 12× magnification. The data were analyzed using the Chi-square and Fisher’s exact tests and the level of significance was set at 0.05.

Fracture and other defects were not found in the control groups. In canals with curvature (0-20°), WaveOne caused the maximum dentinal defects and RaCe produced the least. Moreover, in canals with curvature (20-40°), One Shape caused the maximum dentinal defects while WaveOne and RaCe caused equal dentinal defects approximately.

There was a statistically significant relationship between the performance of RaCe and One Shape in canals with curvature (0-20º) and (20-40º), (p Value< 0.05) while no statistically significant difference was observed in connection to the performance of WaveOne (p> 0.05).

Statement of the Problem:

 Developmental anomalies such as dilacerations can affect the eruption pattern of permanent anterior teeth. They are characterized by a curvature in the crown and roots of the teeth relative to their normal axis. This anomaly can cause some complexities in routine dental treatments such as root canal treatment, orthodontics, and surgery.

The purpose of this study was to assess the prevalence of dilaceration in maxillary and mandibular anterior and canine teeth in Shiraz, Iran using cone-beam computed tomography (CBCT).

In this retrospective study, a total of 1537 encompassed 400 CBCT images collected from 4 private radiology clinics in Shiraz were assessed. Each tooth was radiographically examined in order to diagnose root dilacerations considering their location (apical, middle, coronal), position in the jaw (maxillary or mandibular), direction (mesial, distal buccal and palatal/lingual), and severity of dilaceration (mild, moderate, and severe). The obtained data were analyzed by Chi-square statistical test and Fisher’s exact test. 

In this study, out of 1537 studied teeth, 5.98% had dilaceration. The maxillary and mandibular canine teeth (9.8% and 9.7%, respectively) were significantly the most common teeth involved in this anomaly (p< 0.001). The distal direction with mild severity in the apical third of the root was also the most common result obtained from this study (p<0.001). In addition, there was no statistically significant relationship between gender and type of jaw regarding the prevalence of dilaceration in the studied dental groups (p=0.670 and p=0.231, respectively).

In the current research, it was demonstrated through CBCT records that the prevalence of dilaceration in maxillary and mandibular anterior and canine teeth is relatively uncommon. The most prevalent dilaceration was found to be distal direction with mild severity in the apical third of the root.

Statement of the Problem:

 Enamel organ (EO) is an ectodermal derived structure, which is involved in the different aspects of tooth development. Tooth development shares the same regulatory molecules and genes expressed in other developing organs. Endothelin- 1 (ET-1) and Endothelin A receptor (ETAR), (ET-1/ETAR) axis, are involved in differentiation of embryonic stem cells and organ development.

The present study aimed to investigate the ET-1 and ETAR expression profiles during the development of human primary tooth EO with the relatively large sample size.

In this experimental study, 33 human fetuses aged from 13 to 23 weeks (3 samples from each fetal age) were collected. The samples were divided into three age groups (<16 weeks, <19 weeks, ≥19 weeks) and cut for hematoxylin and eosin (H&E) and immunohistochemistry (IHC) staining. A two-way ANOVA test was conducted to examine the expression levels of ET-1 and ETAR in different layers of human primary tooth EO. The statistical significance was assumed at p ≤ 0.05.

There were statistically significant differences between the expression levels of ET-1/ETAR axis in the four-layered human primary tooth EO in different fetal ages (13-23 weeks). Besides, there were significant differences between the expression levels of ET-1/ETAR axis in all layers of human primary enamel organ and types of teeth.

Due to the profile of expression of ET-1/ETAR axis, it can be concluded that this axis contributes to the differentiation of all human primary EO layers and secretion of enamel. ET-1/ETAR axis is one of the signaling molecules, which may have crucial roles in tooth development.

Statement of the Problem: 

Different software capabilities have been used in digital systems to increase the diagnostic quality of radiographic projections. Considering the availability of different enhancement techniques, it is necessary to determine the suitability of each technique for various diagnostic cases. There is controversy between studies over the effect of different digital enhancement techniques on the accuracy of file length measurements in endodontics.

The present in vitro study aimed to determine the effect of the software capabilities on the diagnostic accuracy to determine endodontic file lengths in photostimulable phosphor (PSP) radiographs.

In the present in vitro study, standard access cavities were prepared in 44 extracted human single-rooted permanent teeth. An endodontic file was placed in each root canal. PSP sensors were used for digital imaging using the parallel technique. All the images were reviewed on a same monitor; once normally with no software enhancement and once using software manipulations including pseudo-color, sharpness, emboss, and edge enhancement. The distance from the file tip to the rubber stop was measured on the images by an electronic ruler.

Significantly, all of the image enhancement techniques presented shorter measurements comparing to the actual length. The results revealed the significant accuracy of the measured error in the pseudo-color enhancement technique compared to other techniques.

The results revealed significant differences between the initial measurements (the gold standard) and those made on the manipulated radiographs. In all cases, the measurements were significantly lower than the real values. Therefore, none of these digital enhancement techniques can increase the accuracy of file length measurements significantly. However, manipulation with the pseudo-color option resulted in fewer errors compared to other options and the normal images. Hence, for precise measurements of the endodontic file lengths, pseudo-color processing algorithm can be suggested when using PSP sensors.

Statement of the Problem:

 Tooth discoloration in the form of staining is a common finding during conventional orthodontic treatment. Due to elevated esthetic standards, clinicians in the field of orthodontics are faced with increasing demands by patients to perform bleaching treatments while the appliances are still in place. Though the success of such treatments has been reported in literature, the effect of whitening agents on orthodontic appliances has not been evaluated. Increased ion release following corrosion of orthodontic brackets is considered a health hazard.

In this study, we measured the amount of ion release from steel brackets under home and office bleaching treatment in order to evaluate the safety of such treatments during orthodontic therapy.

In this experimental study, a total of 120 brackets were randomly divided into 3 groups. The first group was subjected to an office bleaching regimen (hydrogen peroxide 40%). The second group was subjected to a home bleaching treatment (carbamide peroxide 20%). The third group did not receive any bleaching treatment. The specimens of all groups were immersed in artificial saliva and after 30 days, the amount of released chromium, copper, iron, magnesium, and nickel ions was measured and compared using one way ANOVA.

The results showed that ion release was significantly different between the three groups (p Value >0.05). For the chromium, iron, magnesium, and Nickel ion release the order was as follows: no bleaching < home bleaching < office bleaching. However, the copper ion release was greater in the group that received home bleaching.

Ion release was enhanced when bleaching treatments were performed, with office bleaching having a more significant effect. Although the amounts of released ions were less than those permitted by WHO, we suggest that the clinicians recommend home bleaching for orthodontic patients that are seeking tooth whitening treatment.

Recurrent oronasal fistula closure is a challenging phenomenon that has been managed with many surgical or flap techniques, such as local, regional, and distant flaps, with various modifications. Despite these options, the ideal method to repair this kind of chronic fistula has not yet been established. It is difficult to repair because recurrent surgical repairs or interventions cause this region to become more fibrotic with less vascular tissue, which considerably reduces the likelihood of closing this kind of fistula. For this reason, surgeons and researchers continue to work to overcome these obstacles by using more regional, vascular, and neighboring tissue. Classic cleft palate repair techniques use double-layered, nasal, and oral side closure and even a three-layered technique (e.g. plus levator veli palatini and tensor veli palatini muscular repair) in the soft palate region. Hence, we used partial orbicularis oris muscle with enough vascular supply to repair the nasal side and cheek mucosal flap to repair the oral side as a double-layered repair technique. Two years later, during routine patient follow-up, no complications were identified, and the patient’s satisfaction with this treatment was acceptable.

Hemangioendothelioma is a diverse set of proliferative and neoplastic vascular lesions with biological characteristics that fall halfway between benign hemangioma and malignant angiosarcoma. Hemangioendothelioma of the oral cavity is extremely rare and if present, it is seen on lips, gingiva, tongue, maxilla, and mandible. The following case report is about a lesion on the right ventrolateral border of the tongue of a six-year-old female patient. A Laser excision was done. Histopathology revealed the features of hemangioendothelioma. An immunohistochemical (IHC) study was done to correlate the findings with a histopathological picture and arrived at the final diagnosis of epithelioid hemangioendothelioma (EHE). The patient was followed up for two years and no recurrence was noticed.