Journal of Dental Research, Dental Clinics, Dental Prospects
Volume:14 Issue: 4, Autumn 2020

It has been noted that there is a correlation between diabetes mellitus (DM) and changes in the oral cavity. The present study was conducted to estimate, compare and correlate serum and salivary glucose, IgA levels and salivary candidal carriage in diabetics and non-diabetic individuals.

Total of 88 subjects were categorised into 3 groups: Group I (Controlled DM; n=27), Group II (Uncontrolled DM; n=32) and Group III (Non-diabetics; n=29). Serum and salivary glucose levels were assessed with glucose oxidase peroxidase method, Serum and salivary IgA by means of diagnostic kit, Candidal colonization by inoculating sample into sabouraud dextrose agar plate. The data was analysed by One way ANOVA test, Tukeys multiple posts hoc test and Pearson correlation coefficient.

Serum IgA levels were significantly elevated in Group II compared to Group III and significant fall in salivary IgA levels from Group I & Group II. Candidal carriage were significantly higher in Group II compared to Group III. We found statistically significant correlation in serum glucose and salivary IgA levels in Group I. There was a positive correlation among the levels of serum/salivary glucose and serum/salivary IgA levels in Group II. In Group III, there was significant correlation between serum glucose and serum IgA.

Saliva could be a potentially non-invasive diagnostic tool to estimate glucose level. Evaluation of salivary constituents like IgA could be beneficial in the description and management of oral manifestations in diabetic individuals. The rise in levels of salivary glucose likely contributes to increased candidal carriage in turn susceptible to oral candidiasis.

Abstract Background. The aim of this in vitro study was to compare the effectiveness of WaveOne and ProTaper Gold system in removing the Enterococcus faecalis biofilm. Methods. 38 mandibular premolars were selected. The canals were assigned to standard control groups (canals serially enlarged with ProTaper Gold S1-S2-F1-F2, n=15) and experimental (canals enlarged with Primary WaveOne file, n=15). Canals were sampled after the instrumentation procedures, and the colony forming units (CFU) count was evaluated. Samples were also visualized under a fluorescent microscope to count viable bacteria. Data were statistically analyzed using Independent Sample T-test and Paired Sample T-test. Results. Results showed that in comparison with the ProTaper group, WaveOne group displayed the least viable bacteria (P=0.004), Conclusions. Therefore, we concluded that the WaveOne reciprocating file is more successful in reducing intratubular viable bacteria compared with the ProTaper Gold rotary system.

Designing a high strength all-ceramic fixed partial denture with favorable esthetics can be challenging for clinicians; this study aims to evaluate the effect of connector size and design on fracture resistance of monolithic zirconia fixed dental prosthesis.

Two groups of twenty 3-unit monolithic zirconia (Sirona inCoris TZI, Sirona Dental Systems GmbH) bridges extending from mandibular first premolar to the first molar with different connector size (9 mm2, 12 mm2) were divided into two subgroups with different connector design (round and sharp). The specimens were subjected to the 3-point bending test to obtain the fracture-bearing load. The results were reported using descriptive statistics (mean ± standard deviation). To compare the fracture load in two types of designs for each connector size, and two types of connector size for each connector design, Mann- Whitney U test was used. The significance level was considered as p<0.05.

The minimum failure load was related to the group with 9 mm2 connector dimension and sharp embrasure design (1054.4±133.89 N), and the highest mean value belonged to the group with 12 mm2 connector dimension and rounded embrasure design (1599.8±167.09N). Mann-Whitney U test indicated a significant difference between the mean failure load of the rounded and sharp embrasure designs in 9 mm2 connector dimension (p=0.007). However, the difference was insignificant in 12 mm2 connector dimension (p=0.075).

Sharp embrasure design is not recommended for high-stress areas with restricted occlusogingival height. Nine mm2 connector dimension for 3-unit monolithic zirconia FDP, which is recommended by the manufacturer should be used more cautiously.

Background. Dental caries is the most important reason for tooth loss. Clinical examination is the most commonly used technique for occlusal caries diagnosis. Diagnostic power of digital systems is a matter of controversy in this field. The aim of the present study was to determine the diagnostic accuracy of two photostimulable phosphor plate (PSP) systems for early occlusal dentin caries in vitro. Methods. A total of 69 extracted molar and premolar teeth were used in this study. The teeth were mounted in triple blocks and standard radiographs were taken by the Digora and Acteon digital radiographic systems. The original and enhanced-filter 1 radiographs were evaluated by two experienced observers twice at an interval of two weeks and dentin caries were recorded in Tables prepared for the purpose of the study. Then the teeth were sectioned in a buccolingual direction and evaluated under a stereomicroscope. The observers’ reports were compared with microscopic findings as the gold standard. SPSS 23 was used to calculate kappa coefficient, sensitivity, specificity and the area under the ROC curve (AUC). Statistical significance was set at P<0.05. Results. The internal and the external agreement in both imaging systems was good to excellent. The means of sensitivity, specificity and AUC, in the Acteon system were 34.1, 92.9 and 0.674, with 30.8, 94.8, 0.659, respectively, in the Digora system. Conclusion. Accuracy of early occlusal caries diagnosis was poor on both systems and no significant difference was observed between the two systems at 95% confidence interval. Although the AUC was a little higher in the original images, there was no significant difference between them; however, due to their high specificity, they can prevent unnecessary treatments in the clinic.

Local or systemic issues may prevent the installation of a sufficient number of dental implants for fixed prosthetic rehabilitations. Splinting dental implants and natural teeth in fixed dentures could overcome such limitations. Therefore, this study aimed to evaluate the influence of the number of dental abutments in the biomechanics of tooth-implant supported fixed partial dentures. Null hypothesis was that increasing the number of abutment teeth would not decrease the stress over abutments and surrounding bone.

Left mandibular lateral incisor, canine, premolars, and molars were reconstructed through computed tomography and edited using image processing software to represent a cemented fixed metal-ceramic partial denture. Three models were set reducing the number of abutment teeth: 1) lateral incisor, canine, and first premolar; 2) canine and first premolar; 3) first premolar. Second premolar and first molar were set as pontics and second molar was set as implant abutment in all models. Finite element analyses were performed under physiologic masticatory forces with axial and oblique loading vectors.

After simulation of axial loads, the stress peaks on bone around the implant, bone around the first premolar, and prosthetic structures did not experience major changes when the number of abutment teeth was reduced. However, under oblique loads, decreasing the number of abutment teeth led to increased stress peaks on the surrounding bone and denture.

Increasing the number of dental abutments in tooth-implant supported cemented fixed partial denture models led to the reduction of stress on its constituents, favoring the prosthetic biomechanics.

The study aims to investigate the endodontic debridement efficacy of the different sodium hypochlorite (NaOCl) irrigation regimens with and without ultrasonic agitation followed by ethylenediaminetetraacetic acid (EDTA) via scanning electron microscope (SEM) after the rotary instrumentation system.

Single-rooted teeth (n=50) were randomly divided into 5 experimental groups (n=10) and root canals were prepared with ProTaper Universal rotary system up to F3. The root canal system was treated with intracanal heated (100°C) NaOCl or preheated (55°C) NaOCl followed by ultrasonic agitation and EDTA treatment. Samples irrigated with conventional needle irrigation using normal saline were used as controls. Debridement efficacy was analyzed by scanning electron microscope (SEM). A five-point scale was used to estimate the presence/absence of debris for each canal segment (coronal, middle, and apical). Data were analyzed using One-Way ANOVA and post-hoc Tukey tests (P<0.05).

All experimental groups had less debris than the control (P<0.05). The amount of debris decreased significantly for the group with NaOCl intracanal heating compared to extraoral heating. The ultrasonic agitation further enhanced the root canal debridement efficacy of NaOCl.

In summary, with and without ultrasonic agitation of the intracanal heated NaOCl followed by EDTA appears to be very promising in eliminating debris from the root canal system.

To evaluate the bond strength of metal and ceramic brackets bonded to different CAD/CAM ceramic substrates etched with hydrofluoric acid vs. phosphoric acid.

One hundred and twenty CAD/CAM ceramic blocks in 12 groups were fabricated from 3 different CAD/CAM ceramic materials; VITABLOCS Mark II, VITAENAMIC and IPS e.max CAD. Each ceramic material group was divided into two etching groups; one treated with 9.5% hydrofluoric acid (HFA) and the other treated with 37% phosphoric acid (PA). Sixty metal and ceramic brackets of upper right central incisor were bonded to the HFA treated blocks. Another 60 metal and ceramic brackets were bonded to the PA treated blocks. All bonded specimens were thermocycled prior to shear bond strength (SBS) testing. Then the mode of bond failure was recorded.

There was no statistically significant difference in SBS values between the three CAD/CAM ceramic materials. The HFA treated specimens presented a statistically significant higher SBS values than the PA treated specimens. Also, the SBS values of ceramic brackets were significantly higher than those of metal brackets. The adhesive remnant index (ARI) scores were 4 for most of the groups; meaning that almost no adhesive remained on the porcelain surface.

The type of the CAD/CAM ceramics does not influence SBS but HFA yield significantly higher SBS compared to PA.

This study was designed to compare the force decay pattern of two different orthodontic active tiebacks which were exposed to five different commercially available mouth rinses.

In this in vitro study ninety transparent active tiebacks (ATB) and ninety gray ATB were divided into 6 groups. One was the control group and the others were exposed to one of these mouth rinses twice a day for 60 seconds: Listerine, chlorhexidine, Orthokin, Persica and fluoride. The initial force of ATB was 250 gr at 24 mm extension. The force of active tiebacks was measured on the 1, 7, 14 and 28 following days by a digital gauge.

The highest percentage of force loss was observed between the days of 14 and 28 (p<0.05). At the end of the study, persica group had the highest amount of force degradation among both types of ATB. In transparent group it was followed by Orthokin, Listerine, fluoride, chlorhexidine and control respectively. While, in the gray group, Orthokin, chlorhexidine, control, Listerine and fluoride came orderly. In some groups the differences between transparent and gray ATB was significant. In the control group, the force of transparent ATB was significantly greater than gray ones on 7th and 14th day but not significantly after 4 weeks.

Active tiebacks force degradation could be exacerbated by use of some mouth rinses. There were some differences between force relaxation pattern of transparent and gray ATB, of which the knowledge could be beneficial in choosing appropriate O-rings for making ATBs.

This study was conducted to investigate root canal overfilling with different material placement techniques in primary teeth.

A systematic search was undertaken by searching Pubmed/MEDLINE and Scopus for English language peer-reviewed articles published until February 2018 that reported overfilling of primary tooth pulpectomy. Two reviewers independently screened and identified studies against the selection criteria and independently collected the data using a specially designed data extraction form. Overfilling rate was the primary summary measure. The weighted pooled overfilling rates were estimated by random-effects meta-analysis.

Twenty clinical and 4 in-vitro studies satisfied the eligibility criteria. In the clinical studies, the pooled overfilling rate for Zinc-Oxide Eugenol was 23.3% with Lentulo mounted in handpiece, 22.7% with Lentulo, and 17% with plugger techniques. The pooled overfilling rate for Calcium hydroxide-based materials was 16.7% with Lentulo mounted in handpiece, 14.7% with Lentulo, 19.6% with provided syringe, and 25.7% with plugger techniques. In the in-vitro studies, neither individual overfilling rates nor two by two comparisons were subjected to meta-analysis because of the inadequate number of studies.

The lowest overfilling rate in the clinical studies was with plugger and hand-held Lentulo techniques for ZOE and calcium hydroxide-based materials, respectively.

The authors of the article entitled «Comparison of the effect of bleaching with 15% carbamide peroxide and 35% hydrogen peroxide on flexural strength of Cention N in self-cured and dual-cured polymerization modes» which appeared in J Dent Res Dent Clin Dent Prospects 2020; 14(2):105-109, have requested to update the Acknowledgement section of their article by adding the following sentence: «This study was supported by a grant (No. 63149) from Tabriz University of Medical Sciences.» The original version of the article has been updated to reflect these corrections.