Immunohistochemical expression of Cyclooxygenase 2 reflects the proliferative activity in the epithelium of odontogenic lesions

Purpose: Odontogenic cysts and tumors comprise a major component of lesions of the oral and maxillofacial region. The pathogenesis of these lesions involves the interaction between the odontogenic epithelium and the ectomesenchyme. However, the clinical behavior of these biological entities is unpredictable. The aim of this study was to evaluate the role of Cyclooxygenase 2 (COX-2) in the pathogenesis and prognostication of odontogenic lesions.Material and method: : In this study formalin-fixed paraffin-embedded tissue section of Odontogenic Keratocyst (n=10) Dentigerous cyst (n=10), Radicular cyst (n=10) and unicystic ameloblastoma (n=10) were immunohistochemically stained with COX-2 (NCL2-COX-2- 4H12) and with Ki 67 (Ki-67 GM001) using standard staining protocols. The cytoplasmic expression of COX-2 in all the lesions was semi-quantitatively assessed. The pattern of expression of COX-2 among the different odontogenic lesions was statistical analyzed using the ANOVA test and the chi-square test.Results: All the 40 odontogenic lesions that were evaluated expressed COX-2 immunohistochemically. A high number of odontogenic epithelial cells expressed COX-2 in most of the odontogenic keratocyst, radicular cyst and unicystic ameloblastomas. The expression of COX-2 was significantly (p=0.036) higher in Unicystic Ameloblastomas and Radicular cyst compared to that of Odontogenic Keratocyst and the dentigerous cyst.Conclusion: The recognition that expression of COX-2 by odontogenic epithelial cells may indeed shed a new light on the biological mechanisms involved in the development of these benign yet aggressive lesions of the jaws. An insight into the molecular interactions occurring in the odontogenic epithelium will aid in better management of these lesions.

Effect of chlorhexidine, honey and Propolis on Streptococcus mutans Counts: in vitro Study

Objective: .Streptococcus mutans is considered one of the bacteria that causes necrosis, as it metabolism sugar to obtain energy, producing an acidic environment and causing depression in the enamel surface, which causes the dissolution of the calcium molecule, a problem of cavited in the tooth; so the aim of the research is to evaluate the effect of mouthwashes chlorhexidine 0.12% - honey 50% - propolis 5% on Streptococcus mutans in children.Study design: A laboratory study to assess the efficiency of chlorhexidine, honey and Propolis on Streptococcus mutans counts. The sample included 60 children divided into: G1 (Chlorhexidine 0.12% = 20 children), G2 (Propolis 5% = 20 children), G3 (Honey 100% = 20 children). The data was analyzed using the statistical analysis program SPSS, version 13.00, at a confidence level of 95% (P <0.05(. Paired sample T test was used to compare the variable means of the values of the studied variables.Results: There is significant difference between three groups. The reduction ratio was 89.97% in G1, 85.49% in G2 and 76.29% in G3.Conclusion: This study demonstrated the effectiveness of mouthwashes of chlorhexidine, propolis and honey on the bacteria of Streptococcus mutans.

Comparison of force decay pattern in orthodontic elastomeric chains and NiTi closed coil springs, affected by five different mouthwashes: An in vitro Study

Background: The aim of this study was to compare the force decay pattern of elastomeric chains and NiTi coil springs which were exposed to five different commercially available mouthwashes.Methods: In this in vitro study, 60 pieces of elastomeric chain (EC) and 60 NiTi closed coil springs (CS) were divided into 6 groups. The specimens were exposed to one of these mouthwashes twice a day for 60 seconds: Listerine, chlorhexidine, Orthokin, Persica, fluoride and artificial saliva as the control group. The elastomeric chains and NiTi springs were stretched so that they exert the initial force of 250 gr. Their force was measured on the 1, 7, 14 and 28 following days by means of a digital gauge.Results: Elastomeric chains and coil springs had force decrease over time, but EC' force reduction was greater with the highest reduction rate in the first week. However, in the CS group, the force decrease wasn't statistically significant in the first two weeks. After 28 days in the control groups, 49.8% of the initial force was remained in ECs while the value was 93.3% for CSs. In comparison between mouthwashes, in EC groups, in all mouthwashes except Persica, the remained force was statistically less than control group.Conclusion: Force degradation of elastomeric chains could be exacerbated by use of mouthwashes. About coil springs, force decay was also observed. However, it was not statistically significant. Force reduction was detectable after four weeks of coil springs usage, but in EC groups, the greatest reduction was after the first week.

Durability of different types of Mouthwashes on the Salivary Buffering system in Orthodontic Patients.

The fast elevation of the salivary pH in orthodontic patients has acritical role to safe the teeth and encourage the orthodontic treatment after acidic challenger. As their baseline salivary pH is dropped during fixed orthodontic treatments.Aims: this study was aimed to evaluate the durability of three types of mouthwashes on the salivary buffering capacity in orthodontic patients at 0, 5, 10, 15 mints after acidic challenger using direct pH meter.Material and method: 80 orthodontic patients; age range (13-21years) were distributed into four groups; 20/ each, the salivary pH were recorded using compact pH meter (LAQUAtwin, HORIBA's, Kyoto, Japan) before and after administration of carbonated beverage (100 mm coca cola) and directly after gargling with 100 ml of the tested mouthwashes (herbal, green tea and chlorohexidine mouthwash) beside tap water as placebo control. The pH was documented again at 0, 5, 10 and 15 mins after each mouthwash gargling. One way ANOVA analysis and Duncan multiple were used for salivary pH analysis, p≤0.05.Results: non-significant differences were found at 0, 5, 10, 15 mints in comparison with baseline pH after herbal mouthwash gargling, the same result was shown with chlorohexidine mouth wash but with less defined border. Salivary pH after green tea gargling showed clear oscillatory results after the same tested periods.Conclusions: Herbal mouthwash is the best type to improve salivary pH for longer duration after acidic challenger. While Chlorohexidine mouthwash shows beneficial effects in elevation salivary pH with less duration. Green tea mouthwash fail to control salivary pH for long duration.

Oral health status, attitudes and gender variations among governmental school children at Al-Mafraq governate – Jordan

Objectives: Calculate the prevalence and severity of dental caries and periodontal health among school students aged 12-18 years old and their attitudes toward dental health and oral hygiene at Al-Mafraq governate- Jordan.Materials and methods: Demographic and oral behavioral information were collected; students aged 12-18 years old from six public schools distributed over three districts in Al-Mafraq governate over a six-month period had a full oral and dental examination. DMFT index (Decay, Missing, Filling, Teeth) was used to measure caries experience. Plaque index (PI) and gingival index (GI) of Löe and Silness were used to evaluate the oral health status. T - test was used for statistical evaluation. A P-value < 0.05 was considered statistically significant.Results: 1165 students were examined, 51% never had been to a dentist or had any previous dental treatment, 39.6% of the students examined never brushed their teeth and 61.85 % had dental caries. The (SiC) was 4.72 with a decay representing 93.53%. Females brush their teeth more frequent than males with a statistically significant difference; p< 0.001. Females showed lower DMFT index (1.81) and compared to males (2.25) with a statistically significant difference. Females showed lower SiC (4.164) compared to males (5.186) with a statistically significant difference. There was no statistically significant difference between males and females in PI p= 0.590, and GI; p= 0.852.Conclusions: The prevalence of dental caries among students in Al-Mafraq governate and the significant caries index were substantially higher than the target goals of WHO/ FDA of year 2015 with more than 90 % of unmet treatment needs. Girls showed better oral hygiene habits compared to boys and exhibited less dental caries experience. However, periodontal status did not differ significantly between both genders.

Do different time intervals in placement of restorative materials over calcium silicate cements, affect interface microhardness of different restorative materials?

Objectives: The type of materials and application time of final restorations on calcium silicate cements (CSCs) are important factors which influence the interfacial properties. The aim of this study was to investigate the effect of different placement time of RMGI (Resin Modified Glass Ionomer), composite resin and amalgam over different CSCs on the surface microhardness of these restorative materials.Methods: Each CSCs material (Biodentine, MTA, CEM cement) was mixed and carried into a hole (6mm diameter ×4 mm thickness) in the center of 270 molds (n=90 /each CSC). Then these molds were randomly divided into three main experimental groups (n=30) in regard of restorative materials (Amalgam, RMGI, Composite) that were placed in the other molds with the same hole size to make restorative materials and CSCs in contact together. Afterwards, each experimental group was divided into three subgroups according to the time interval of restoration placement that was immediately, after 24h and after 72h (n=10). Two molds were separated from each other after one week storage in incubator with 100% humidity in 37 °C, in order to evaluate the Vickers microhardness of restorative materials in CSC-restorative material interface. Statistical analysis included two-way Anova followed by Post hoc Dunnett T3 in cases with lack of homogeneity and Tukey HSD in cases with homogeneity.(p=0.05)Results: The microhardness of all restorative materials was neither significantly influenced by the CSCs materials (p>0.05) nor by the timing of final restoration (p>0.05) except in RMGI in immediate contact with CEM cement. (p<0.001)Conclusion: Restorative materials hardness in interface with studied CSCs may not affect. This in vitro study found no evidence against immediate definitive restoration over CSCs.

Evaluation of the Most Common Dental Procedural Errors Leading to Lawsuits and the Relevant Reasons in Three Dental Clinics in Tehran

One of the most important occupational stresses that dentists encounter in their profession is patients’ lawsuits. The present study aimed to evaluate common procedural errors that lead to lawsuits in dentistry. In the present cross-sectional study, all the patient files of three large dental clinics in Tehran were evaluated from 2014 to 2019, in which a dentist’s negligence had been confirmed by the specialty dental committee. Files with incomplete clinical data, without the dentist’s name, and the type of the lawsuit were excludeda and Finally, 107 lawsuit files were confirmed and entered the study. After extraction of the data from the existing files and completing the relevant checklist, data were analyzed with SPSS 23. Most lawsuits were of the therapeutic type (88 cases, 82%), with 34 cases (31.9%) , 26 cases (24.2%) and 19 cases (17.6%) related to prosthodontics, endodontics, and surgery, respectively. Most plaintiffs were 30–49 years of age (56 cases ,52%), and most were women (70 cases, 65%). Over half of the lawsuits had been filed against dentists with a job experience of <10 years and against general dental practitioners (81 cases, 76%). One of the most important ways to prevent errors leading to lawsuits is to increase dentists’ knowledge about previous lawsuits. Knowledge about the most common lawsuits and the provision of organizational guidelines will help manage and decrease such lawsuits.

Stress analysis of over-denture abutments treated with two obturation techniques

Aim: Evaluation of stresses induced on over-denture abutments endodonticaly treated with two different obturation techniques.Materials and methods: eight mandibular permanent canines were inserted in four pesudo-realistic models. In each model two canines were placed in it. One canine was treated with lateral obturation technique and the other canine with vertical obturation technique. Four over-denture prostheses were fabricated on the four models. Then strain gauges were attached on the coronal one third of the root buccally and lingually for all eight canines. A metal rod was placed occlusally on the premolar –molar area, and a 50 N load was applied on the middle of the rod using the universal testing machine. Readings were collected. Results: from the collected data the lateral obturation showed 85.25±104.901 µε and the vertical obturation showed 4.875±3.555 µε with significance difference of P<0.05 between the groups.Conclusion: it can be concluded that the abutments treated with vertical obturation techniques reduced the stresses induced to the supporting structures when compared with the lateral condensation technique.

Long term radiographic evaluation of a potentially impacted and dilacerated tooth into complete transposition

Background: Anomalies such as ectopic tooth eruption and transposition are challenging situations that may complicate the orthodontic treatment. Some of these anomalies can only be diagnosed and managed by accurate long-term radiographic examination. Delayed diagnosis could impede simple preventive orthodontic measurements and cause more costly and consuming future complicated orthodontic treatment.Case Description: We described in detail the long term follow-up of a young female patient referring with a unilateral ectopic eruption. The patient was under close observation and regular orthodontic treatment to guide a unilateral ectopic eruption into a complete transposition of an upper left canine and first premolar. The long term follow-up revealed stables results.Practical Implications: Early diagnosis and preventive measurements in patients suffering from anomalies such as ectopic eruption is crucial in order to avoid further complications such as tooth impaction and dilaceration formation and adopting the best choice of treatment.

Assessment of dehiscence and fenestration in children and adolescents using cone beam computed tomography

Objectives: To define the prevalence of dehiscence and fenestration and classify them in terms of the localization of fenestrations in a random sampled group of children and adolescent patients using cone-beam computed tomography (CBCT).Methods: CBCT performed at the Department of Oral and Maxillofacial Radiology of patients referred by the paediatric dentistry clinic were included in this retrospective study. Image evaluations were performed by dentomaxillofacial radiologist (AA, asst. prof.), and these images were examined in three dimensions of the axial, coronal, and sagittal planes. Intraexaminer agreement for the evaluations were found acceptable. The presence/absence of dehiscence and/or fenestration, fenestration’s classification type, and localization of defects were recorded. Moreover, the presence/absence of periapical lesion in related root with dehiscence and fenestration was noted. For statistical analysis, The Chi-Square test, Fisher Freeman Halton Test, and Yates' Continuity of Correction were used.Results: 3061 roots in 1801 teeth of 120 cases were analyzed. The mean age was 9.97±2.22 years. Dehiscence was detected in 261(8.5%) roots of 161(8.9%) teeth, and fenestration was detected 63(2%) roots of 36(2%) teeth. The most common fenestration type was Type I, followed by Type II and IV. Dehiscence was observed more frequently in primary teeth than permanent teeth, and the difference was statistically significant (p:0.000). Dehiscence and fenestration incidence in maxillary teeth was significantly higher than in the mandibular teeth (pdehiscence:0.000, pfenestration:0.004). Apical lesions were observed more in primary teeth than permanent teeth for both defects.Conclusions: This study concludes that alveolar dehiscence and fenestrations are more common in primary teeth than permanent teeth. Moreover, these defects were detected more for the teeth in the maxilla. Concerning endodontic and orthodontic therapies in maxilla, use of CBCT is useful in determining the region's anatomical structure accurately in suspected cases of child and adolescent patients.