Dental Hypotheses
Volume:14 Issue: 2, Apr-Jun 2023

This research aims to compare the distribution of stresses and general displacements between different dental implant abutments against a healthy tooth, as well as the mechanical behavior of the carbon fiber-reinforced polyether-ether-ketone (CFR-PEEK) material under load conditions.

A biomodel of a healthy tooth was implemented by computed tomography (CT), considering three essential parts of the tooth (enamel, dentin, and pulp). Three different dental abutments were produced using the SolidWorks computer program. Applying the finite element method (FEM), a numerical evaluation was performed by introducing a critical load of 550N and then unloading it to 0N taking into consideration the behavior of the material (titanium and CFR-PEEK) as bilinear, isotropic, and homogeneous.

The difference in stress and total displacement between the dental implant (titanium and CFR-PEEK) and the healthy tooth was significant, going from critical stress values of 1087 to 324 MPa.

When removing the load from the CFR-PEEK material, it presented residual stresses because the material passed its elastic limit despite this, demonstrating a better mechanical behavior than titanium.

We aimed to compare the changes in the two salivary biomarkers, RANKL and RANK, among patients with healthy gingiva on reduced periodontium versus generalized periodontitis stages II and III.

Study subjects were divided into three groups: (1) healthy periodontium (control group) (n=15), (2) generalized periodontitis stages II and III (n=30), and (3) healthy gingiva on reduced periodontium (n=30). Salivary levels of RANKL and RANK were assessed using an enzyme-linked immunosorbent assay. Data analysis was done by the one-way ANOVA and the Tukey post hoc test using R software.

There was a statistically significant difference among the three study groups regarding salivary levels of the RANKL (P < 0.001) and RANK (P < 0.001). A Post hoc test showed that the difference between salivary levels of the RANKL (P=0.50) and RANK (P=0.86) among periodontitis groups and healthy gingiva in the reduced periodontium group was not statistically significant.

High salivary levels of RANKL and RANK in comparison with healthy gingiva are not necessarily associated with the active phase of periodontal disease and progressive bone destruction.

We aimed to evaluate the effect of feeding pattern and salivary level of growth hormone on the stage of primary tooth eruption among infants aged 6 to 18 months.

The sample size of this analytical cross-sectional study was 300 healthy infants from Karbala, Iraq. Feeding pattern answered by the parents, stage of dental eruption assessed according to criteria described by Damodar P. Swami, and level of salivary growth hormone determined using an ELISA assay.Data were analyzed via a linear regression model using R software.

The model (adjusted R2: 0.668) showed the feeding pattern (beast, bottle, or mix), gender, and salivary level of growth hormone were not significant predicators for the stage of primary tooth eruption (p > 0.05). Yet, age was a significant predicator (p < 0.001).

The infant’s feeding pattern and salivary level of growth hormone did not affect the timing of the eruption of primary teeth.

 
We aimed to evaluate serum and salivary vitamin B12 levels in patients with iron deficiency anemia (IDA) with and without recurring aphthous ulcers (RAS).

 
Study participants were divided into three groups, clinically healthy control group (n = 25), an IDA patient with RAS (n = 25), and an IDA without RAS (n = 25). The enzyme-linked immunosorbent assay (ELISA) method was used to assess the serum and salivary B-12 levels blindly. Data analyses were performed using one-way ANOVA and the Tukey’s post hoc test using R software.

 
There were statistically significant differences regarding serum and salivary B12 levels among study groups (P<0.001). All pairwise comparisons showed significant differences regarding serum (P<0.001) and salivary (P ≤ 0.002) B12 levels.

 
The Control group (396 ± 18.2 pg/mL) was within the normal serum level of vitamin B12 (200-900 pg/mL), while in IDA with RAS (111 ± 15.4 pg/mL) and IDA without RAS (145 ± 57.2 pg/mL) serum level of vitamin B12 is lower than the normal range and significantly lower than the control group.

We aimed to assess the possible relationship between dental caries prevalence and oxidative stress markers such as protein carbonyl (PC) and total antioxidant capacity (TAOC) of saliva among type 1 diabetic children.

An analytical cross-sectional study was performed among 45 type 1 diabetic children and compared with 45 healthy control children aged 10 to 12 years old. Dental caries was diagnosed and recorded using the decayed, missing, and filling index (DMFS/dmfs). Unstimulated salivary specimens were collected for evaluation of TAOC and PC using an enzyme-linked immune-sorbent assay (ELISA). A linear regression model and one-way ANOVA test were employed for data analysis using the R 4.3.0.

Salivary levels of TAOC and PC, having diabetes, and diabetes status (controlled or uncontrolled) were not statistically significant (P > 0.05) predicators regarding the prevalence of dental caries among type 1diabetic children.

The diabetic status had a significant effect on salivary levels of TAOC and PC, but no significant effect on the prevalence of dental caries.

We aimed to assess the push-out bond strength of BIO-C REPAIR (a ready-to-use bioceramic material), and compare it with the mineral trioxide aggregate (MTA) and аmаlgаm.

A total of 30 single-rooted, straight human maxillary central incisors were chosen. To keep the root canal length at 15 mm, the crown was resected. The teeth underwent endodontic treatment, along with the resection of their root ends and preparation of root-end cavities. The teeth were randomly allocated into three groups as follows: BIO-C REPAIR, MTА, and Zinc-free аmаlgаm. Utilizing a universal testing machine, the push-out test was done and the digital microscope was used to assess failure made. Data were analyzed by the one-way ANOVA and chi-square test using the Python software.

Statistically significant difference was found among study groups regarding push-out bond strength (p <0.001) and mode of failure (p < 0.001). Post-hoc test showed MTA has significantly lower push-out bond strength than BIO-C REPAIR and amalgam (p <0.001).

Within the limitation of this study, the push-out bond strength for BIO-C REPAIR was higher than the MTA and nearly similar to the amalgam.

Enamel demineralization expressed as white spot lesions (WSLs) has been reported to be associated with both fixed and removable orthodontic appliances.

Case report: 

This case report described the management of a patient with clear aligner-related severe enamel demineralization using a modified resin infiltration technique. Microabrasion with Opalustre (Ultradent, Utah, USA) was performed to remove the remineralized enamel surface followed by repeated etching with ICON Etch (DMG, Hamburg, Germany) until the WSLs disappeared after ethanol application. A #12 blade could be used to check whether the superficial layer was demineralized enough for the resin to infiltrate. The ICON-Infiltrant (DMG, Hamburg, Germany) was applied to the etched enamel and light-cured. After treatment, all the WSLs showed improvement with the color nearly matching the adjacent sound enamel.

Modified resin infiltration technique combined with microabrasion could be an effective noninvasive method to treat severe enamel demineralization including shallow localized enamel breakdown. However, more clinical studies are required to assess the efficacy and safety of this method.