Journal of Dental Research, Dental Clinics, Dental Prospects
Volume:10 Issue: 3, Summer 2016

Background. Regarding the lack of comprehensive systematic review on the efficacy of water fluoridation and prevalence of dental fluorosis, the aim of the current research was to systematically study the prevalence of dental fluorosis at different levels of water fluoride in the world and lay emphasis on the amount of fluoride in drinking water.
Methods. Studies were searched in PubMed, Scopus, SID, and IranMedex, with regard to inclusion criteria. Study validity was assessed with some checklists, and analyses were performed to ascertain the prevalence of dental fluorosis among indi-viduals categorized in age groups.
Results. Investigation of the heterogeneity and analysis of the subgroups revealed that in the 6-18 year age group, when water fluoride level was less than 0.7 ppm and there was exposure to water fluoride in the first 6-8 years of life, no signifi-cant heterogeneity was detected among the studies in this subgroup. Thus, the pooled estimation of dental fluorosis preva-lence in this subgroup was 12.9% (95% CI: 7.5-18.3%). Furthermore, meta-regression indicated that the exposure time to fluoride in drinking water, or exposure to fluoride in supplements, diets, air, etc as well as the quality of studies had a signif-icant relation to the difference in the prevalence of dental fluorosis.
Conclusion. The results revealed no heterogeneity in just 2 subgroups, and the results of subgroups could be pooled in them. Furthermore, the number of studies included in this review considerably decreased by considering all the detected confounding factors, whereas other similar systematic reviews mentioned at most 2 factors.

Background. The most common species isolated from primary endodontic infections are black-pigmented bacteria. These species are implicated in apical abscess formation due to their proteolytic activity and are fastidious in nature. Therefore, the present study was carried out to evaluate the presence and identification of various pigmented Porphyromonas and Prevotella species in the infected root canal through culture-based techniques.
Methods. Thirty-one patients with primary endodontic infections were selected. Using sterile paper points, samples were collected from the root canals after access opening and prior to obturation, which were cultured using blood and kanamycin blood agar. Subsequently, biochemical test was used to identify the species and the results were analyzed using percentage comparison analysis, McNemar and chi-squared tests, Wilcoxon match pair test and paired t-test.
Results. Out of 31 samples 26 were positive for black-pigmented organisms; the predominantly isolated species were Pre-votella followed by Porphyromonas. In Porphyromonas only P. gingivalis was isolated. One of the interesting features was isolation of P. gingivalis through culture, which is otherwise very difficult to isolate through culture.
Conclusion. The presence of Prevotella and Porphyromonas species suggests that a significant role is played by these organisms in the pathogenesis of endodontic infections.

Background. The aim of this study was to assess the relationship between genetic taste sensitivity, dietary preferences and salivary flow rate in 6‒14-year-old children for identification of individuals at higher risk of developing dental caries.
Methods. A total of 500 children 6‒14 years of age, of both genders, who reported to the Department of Oral Medicine and Radiology, were included. Propylthiouracil (PROP) sensitivity test was carried out and the subjects whose perception was bitter were grouped as tasters, whereas those who were unable to perceive any taste were grouped as non-tasters. The 2D:4D ratio was obtained by measuring the length ratio of index finger to ring finger with the help of a digital Vernier caliper. Evaluation of dietary preferences was carried out using a 24-hour dietary recall and accordingly they were categorized as sweet likers and dislikers. The salivary flow rate was estimated by collecting unstimulated saliva by spitting method. Data were analyzed with Student’s t-test and chi-squared test.
Results. The results suggested a positive relation between low digit ratio (2D:4D), non-tasters, sweet likers and high caries index among the participants with a highly significant statistical difference (P ≤ 0.000). Tasters had high mean of USSR (0.48) than non-tasters (0.29), which was statistically significant.
Conclusion. The present research revealed a positive correlation between all the parameters evaluated. Therefore an indi-vidual considered as non-taster by PROP was a sweet liker with low 2D:4D ratio, reduced salivary flow rate and high caries index.

Background. Failure of orthodontic bracket bonds is a common occurrence during orthodontic treatment. Different tech-niques have been suggested in the literature to remove resin residues from the bracket bases and enamel surfaces to prepare the surfaces again after debonding. This study attempted to compare multiple rebond shear strengths (SBS) of debonded brackets following preparation with sandblasting and CO2 laser.
Methods. The brackets were bonded on 30 human and bovine maxillary central incisors using self-curing composite resin. SBS was measured using Hounsfield testing machine. The brackets were rebonded for two other times after composite resin residues on their surfaces were removed, either with air abrasion or CO2 laser. The debonded brackets and enamel surfaces were also evaluated after each debonding procedure under a stereomicroscope in order to determine adhesive remnant index (ARI). SBS of debonded brackets after each step were compared between sandblast and CO2 laser groups.
Results. We observed significant differences in SBS values between pre-recycling and first (P = 0.04), second (P = 0.007) and third recycling (P = 0.007) with laser. Recycling with sandblasting resulted in a decrease in SBS after the first and second recycling procedure; however, the SBS increased after the third recycling procedure, with no significant differences.
Conclusion. SBS of brackets after recycling with sandblasting and laser beams was not significantly different, and both were at a favorable level. However, repeating the recycling procedure with sandblasting resulted in more favorable SBS compared to laser.

The inferior alveolar canal must be constantly examined as an important anatomical landmark in the study of lower jaw, particularly posterior body and mandibular ramus sites, in dental and surgical procedures. In the present study, the effect of two pathological lesions, ameloblastomas and keratocystic odontogenic tumour, on canal displacement were investigated.
In total, 26 patients with lesions referred to Tabriz Imam Reza Teaching Hospital were studied in two equal groups (13 patients with a histopathologic ameloblastoma diagnosis and 13 with a histopathologic odontogenic keratocyst diagnosis) after confirming the initial incisional biopsy and pathologic report, the CBCT of the lesions larger than 3 cm mesiodistaly and those involving the posterior body and ramus of mandible, entered the study. Two maxillofacial surgeons with an oral and maxillofacial radiologist examined three points of CBCT imaging to determine the position of the mandibular canal to the lesions from the buccal and lingual aspects.
The results of statistical analysis showed that in ameloblastoma, inferior alveolar canal has been displaced buccally in ramus region (84.6%) but in distally region, displacement was less buccally (41.6%). In KOT it has been no significant difference in displacement of inferior alveolar canal between proximal and distal region of the lesion observed. Finally chi-squared test showed no statistically significant difference between two lesions.
The results of the statistical analysis showed that there was no relationship between these types of lesions and the inferior alveolar canal displacement.

The aim of the present study was to compare coronally advanced flap (CAF) with amniotic membrane to CAF with connective tissue graft (CTG) in the treatment of Miller’s class I&II gingival recessions.
11 systemically healthy patients, with 30 Miller’s class І and ІІ gingival recessions ≥3 mm, were selected and randomly divided into two equal groups. Gingival recessions in the control group were treated with coronally advanced flap and CTG, and in the test group with CAF and amniotic membrane. The clinical parameters including: probing depth (PD), clinical attachment level (CAL), recession depth (RD), recession width (RW), and keratinized tissue width (WKT) were measured at baseline, 1, 3, and 6 months postoperative. A P value RD, RW, CAL, and MGJ position changed significantly between baseline and 1 month postoperatively (p The findings of the present study demonstrated that although use of amniotic membrane resulted in decreasing surgical time and patient morbidity, but superior results were achieved by using CTG.

Transferrin is a negative acute phase protein, which decreases during inflammation and infection. The aim of the present study was to evaluate changes in the transferrin serum levels subsequent to non-surgical treatment of chronic periodontal disease.
Twenty patients with chronic periodontitis and 20 systemically healthy subjects without periodontal disease, who had referred to Tabriz Faculty of Dentistry, were selected. Transferrin serum levels and clinical periodontal parameters (pocket depth, clinical attachment level, gingival index, bleeding index and plaque index) were recorded at baseline and 3 months after non-surgical periodontal treatment. Data were analyzed with descriptive statistical methods (means ± standard deviations). Independent samples t-test was used to compare transferrin serum levels and clinical parameters between the test and control groups. Paired samples t-test was used in the test group for comparisons before and after treatment. Statistical significance was set at P The mean transferrin serum level in patients with chronic periodontitis (213.1±9.2 mg/dL) was significantly less than that in periodontally healthy subjects (307.8±11.7 mg/dL). Three months after periodontal treatment, the transferrin serum level increased significantly (298.3±7.6 mg/dL) and approached the levels in periodontally healthy subjects (P The decrease and increase in transferrin serum levels with periodontal disease and periodontal treatment, respectively, indicated an inverse relationship between transferrin serum levels and chronic periodontitis.

Background. This study was designedaimed to investigate assess the Antimicrobial antimicrobial eEffect of chlorhexidine (CHX) on Aggregatibacter A. actinomycetemcomitans biofilmss extracted isolated from subgingival plaque of Periperi-iImplantitis lesions.
Methods. 13 Thirteen Participants patients requiring peri-implantitis treatment were consecutively selected and theirwere consecutively recruited from patients referred for treatment of peri-implantitis. Patients’ subgingival biofilms were was obtained collected by inserting fine sterile paper points into peri-implant pocket and kept in place for 15 sseconds. A. actinomycetemcomitans was isolated from the This subgingival biofilm went under process and A. actinomycetemcomitans derived from special culturecultured. In this study, the standard strain of A. actinomycetemcomitans as served as the positive control group and a blank disk disc impregnated in with water as served as the negative control group were used.; Volume of 0.1 mLl of this the bacterial suspensions was incubated cultured on specific culture medium and. blank discs (6 mm diameter) impregnated with 0.2% CHX mouthrinse (Behsa Pharmaceutical Co.) impregnated blank disks (6 mm diameter) and negative control discs (not impregnated in 0.2% CHX) were placed on either the two sides of the bacterial culture plate. The size of zone of growth inhibition zone (the distance between the edge of the disc and the edge of the bacterial colony) was measured by a blinded, independent observer in millimetres.
Results. According to the results of disk disc diffusion test, the average mean diameter of growth inhibition zone of A. actinomycetemcomitans around disks discs impregnated with CHX showed significantwas larger zone of inhibition of A. actinomycetemcomitans growth in both standard bacterium(positive control) and biofilm samples of A. actinomycetemcomitans compared to the negative control group (blank diskdisc) (PConclusion. Using Use of 0.2% CHX mouthwash have has antibacterial effects on A. actinomycetemcomitans a species cultured isolated from peri-implantitis sites.

Fracture load of implant-supported restorations is an important factor in clinical success. This study evaluated the effect of two techniques for screw access hole preparation on the fracture load of cement-screw retained implant-supported zirconia-based crowns.
Thirty similar cement-screw retained implant-supported zirconia-based maxillary central incisor crowns were evaluated in three groups of 10. Group NH: with no screw access holes for the control. Group HBS: with screw access holes prepared machinery before zirconia sintering. Group HAS: with screw access holes prepared manually after zirconia sintering. In group HBS, the access holes were virtually designed and prepared by a computer assisted design/computer assisted manufacturing system. In group HAS, the access holes were manually prepared after zirconia sintering using a diamond bur. The dimensions of the screw access holes were equal in both groups. The crowns were cemented onto same size abutments and were then subjected to thermocycling. The fracture load values of the crowns were measured using a universal testing machine. The data were statistically analyzed using ANOVA and Tukey’s test (P The mean fracture load value for the group NH was 888.37±228.92 N, which was significantly the highest among the groups (P Both used techniques for preparation of screw access holes in implant-supported zirconia-based crowns decreased the fracture load.

Background and aims. The aim of this study was to evaluate the sealing ability of Kryptonite bone cement (Doctors Research Group Inc, Southbury, CT, USA) in retrograde cavities by comparing with Mineral Trioxide Aggregate (MTA) (Dentsply Tulsa Dental Specialties, Tulsa, OK, USA), Amalgam and Intermediate Restorative Material (IRM) (Dentsply Caulk, Milford, DE, USA) using ultrasonic retrograde preparation.
Materials and Methods. One hundred extracted single rooted human maxillary incisor teeth were decoronated and the roots were instrumented up to master apical files 40 K file size with Mtwo rotary system and obturated with AH Plus sealer and gutta-percha using cold lateral compaction technique. The specimens were assigned to one control group and four experimental groups according to the retrograde filling materials (n = 20). The specimens were immersed in 0.5% Rhodamine B solution for 48h. Then specimens were split longitudinally into two halves and depth of dye penetration was evaluated under stereomicroscope.
Results. There was statistically significant difference between control group and experimental groups (P0.05).
Conclusions. Kryptonite cement provides optimal apical seal as well as MTA, amalgam and IRM when used as retrograde filling cement.

Retention rate of pit and fissure sealant materials depends on their intactness and integrity related to the enamel surface adherence. Wear characteristic of sealant materials may determine scheduling of check- up visits. Purpose of this study was comparing wear resistance of two flowable composites with posterior composite materials.
Thirty- five disk shaped specimens were prepared in 5 groups including; two flowable composites (Estelite Flow Quick and Estelite Flow Quick High Flow), Filtek P90 and Filtek P60 and Tetric N-Ceram. They were prepared in 25 diameter disk shaped by packing in a two piece aluminum mold and they were light cured. All the specimens were polished during 1minute by 600 grit sand paper. They stored in distilled water at room temperature for 1 week, then they wore by Two Body abrasion test using "Pin on Disk" method (with distilled water medium under 15 N load, 0.05 m/s speed, 100 m distance and Steatite ceramic balls antagonists). Profilometer used for evaluating the surface wear. Data analyzed with the one-way ANOVA test.
Estelite Flow Quick had 2708.9 ±578.1 μm 2 and Estelite Flow Quick High Flow had 3206 ±2445.1 μm 2 wear amounts but there were no statistical differences between all groups. They demonstrated similar wear properties.
Estelite flowable composites have wear resistance similar to nano and microfilled and microhybrid composites which recommended using as pit and fissure sealant material in posterior region with appropriate mechanical characteristic.