Dental Research Journal
Volume:20 Issue: 5, May 2023

As more recent implant biomaterials, Zirconia ceramic and glass or carbon fibre reinforced PEEK composites have been introduced. In this study, bone stress and deformation caused by titanium, carbon fiber‑reinforced polyetheretherketone (CFRPEEK), and zirconia ceramic implants were compared.

In this in vitro finite element analysis study, a geometric model of mandibular molar replaced with implant supported crown was generated. The study used an implant that was 5 mm diameter and 11.5 length. Three implant assemblies made of CFR‑ polyetheretherketone (PEEK), zirconium, and titanium were created using finite element analysis (FEM). On the implant’s long axis, 150 N loads were applied both vertically and obliquely. ANSYS Workbench 18.0 and finite element software were used to compare the Von Mises stresses and deformation produced with a significance level of P < 0.05.

With no discernible differences, all three implant assemblies that is CFR‑PEEK, titanium, and zirconia demonstrated similar stresses and deformation in bone.

It was determined that zirconia and PEEK and reinforced with carban fibres(CFR‑PEEK) can be used as titanium‑free implant biomaterial substitutes.

This study aimed to evaluate the reaction of the periapical tissue to Cold ceramic and mineral trioxide aggregate (MTA) following periapical endodontic surgery.

In this experimental study, a total of 12 mandibular first, second, and third premolars of two male dogs were selected. All procedures were performed under general anesthesia. The access cavities were prepared, and the length of canals was determined. Root canal treatment was performed. A week later, periradicular surgery was performed. After osteotomy, 3 mm of the root end was cut. Then, a 3‑mm cavity was created by an ultrasonic. The teeth were randomly divided into two groups (n = 12). The root‑end cavities were filled with MTA in the first group and with Cold ceramic in the second group. After 4 months, the animals were scarified. Histological evaluation of the periapical tissues was performed. Data were analyzed using SPSS 22 and Chi‑square test and P = 0.05.

The findings showed 87.5% and 58.3% cementum formation in MTA and Cold ceramic groups, respectively, indicating a significant difference (P < 0.001). In addition, the results showed 91.7% and 83.3% bone formation in MTA and Cold ceramic groups, respectively, but the difference was not statistically significant (P = 0.6). Furthermore, the findings revealed 87.5% and 58.3% periodontal ligament (PDL) formation in MTA and Cold ceramic groups, respectively (P = 0.05).

Cold ceramic was able to induce the regeneration of cementum, bone, and PDL; hence, it can be considered as a biocompatible root‑end filling material in endodontic surgery.

The purpose of this study was to evaluate the effect of different surface treatments on the microshear bond strength (µSBS) of resin cement to zirconia‑reinforced lithium silicate ceramic and to compare it with lithium disilicate ceramic.

In this in vitro study, 80 specimens containing two glass ceramics of IPS e.max press and VITA SUPRINITY were prepared and categorized into four groups according to the surface treatments (n = 10) as Group 1 (C): no treatment (control); Group 2 (HF): etching with 9% hydrofluoric acid (HF) for 90 s followed by silane application; Group 3 (SPH): sandblasting with Al2 O3 particles (50 μm), etching with 35% phosphoric acid for 40 s followed by application of silane and adhesive (Clearfil liner bond F); and Group 4 (SB): sandblasting with Al2 O3 followed by silanization. Then, a resin cement (Panavia F2) was applied to the prepared ceramic surfaces. All samples were subjected to thermal aging (5000 cycles, 5–55). The µSBS test was evaluated and failure modes were recorded. Data were analyzed using the Shapiro–Wilk, two‑way analysis of variance and Tukey’s Honest Significant Difference post hoc tests (P < 0.05).

IPS e.max press samples revealed significantly higher µSBS values compared to VITA SUPRINITY (P < 0.001), in whole surface treatments. The HF group showed the highest µSBS value, followed by the SPH and SB groups, respectively (P < 0.001). Adhesive failure was recorded as a predominant failure mode.

The adhesion performance of IPS e.max press was significantly higher than VITA SUPRINITY. The common surface treatment protocol including HF application followed by silanization was the most effective surface treatment for both glass ceramics.

Bone grafting is the primary treatment for the alveolar cleft. Due to the reduced complications by the sealant materials, this study aimed to evaluate fibrin glue’s effect on the success rate of unilateral alveolar bone grafting.

This study was a single‑blind clinical trial performed on 20 patients with a unilateral alveolar cleft. Patients were randomly divided into groups: group A patients as a control group underwent bone grafting without fibrin glue, and in Group B, patients were grafted using fibrin glue. The subject was followed up through routine examination and the cone‑beam computed tomography systems technique for up to 4 months. Paired t‑test and Chi‑square tests were used to analyze the data and the P < 0.05 was considered the significance threshold.

The mean age, gender, and cleft side distribution did not represent significant differences. Before surgery, the average alveolar cleft volume in Group A and B patients was 0.95 ± 0.25 cm3 and 0.99 ± 0.22 cm3 , respectively, which was not statistically different. After the surgery procedure, the alveolar cleft volume in Group A and B patients was determined to be 0.31 ± 0.10 cm3 and 0.23 ± 0.11 cm3 , which represented 66.7% ± 8.9% cm3 and 76.2 ± 11.4 cm3 bone formation, respectively, with no remarkable difference. Our examination did not reveal any necrosis and infection in both groups. However, despite no dehiscence observation in fibrin glue treatment patients, one subject showed dehiscence complication in the control group.

According to results, fibrin glue may increase the percentage of bone volume formed and prevent dehiscence.

Mineral trioxide aggregate (MTA) becomes a hard mass after setting and making it difficult to remove and can cause significant problems in the retreatment process. The aim of this study was to evaluate the effect of different concentrations of hydrochloric acid (HCl) on MTA dissolution and its effect on dentin.

In this in vitro study, 45 single‑root premolars were selected. Artificially open apex was created in all samples with similar process. The samples were randomly divided into 4 experimental groups of 10, and a control group of 5. Four‑millimeter thick apical plugs of Root MTA were placed in all samples in an orthograde manner. HCl was used at concentrations of 3.75%, 7.5%, 15%, and 22.5% (w/v) for the experimental groups and normal saline for the control group. Each sample was exposed to the desired solution for 15 min. Then, MTA retrieval and reaching the working length were attempted with k‑file # 30. The times of each sample were recorded. Furthermore, after longitudinal incision of the roots with a disc, the dentin surfaces of canals were examined with a Dino‑Lite microscope (×50). Results were analyzed by Shapiro–Wilk test and one‑way analysis of variance tests. The level of significance P value was set at 0.05.

The lowest average time of reaching working length was observed with group 22.5% that was significantly lower than 15% and 7.5% concentrations (P = 0.005 and P = 0.011). Furthermore, by examining with ×50 of Dino‑Lite microscope, no difference was observed on the canal walls.

The optimum concentration of HCl was 7.5%. Furthermore, different concentrations of HCl had no significantly different effect on the dentinal canal wall using Dino‑Lite microscope with ×50.

Stresses on prosthetic crown directly influences the survival rate of implants hence it should be considered while selecting prosthetic material. The aim of the study is to evaluate stress analysis on implant, abutment and peripheral bone with change in different abutment and different crown materials by 3D finite element study.

A numerical procedure based on finite element method was adopted to investigate the influence of different prosthetic materials and abutment materials on stress situation. Eight different three‑dimensional (3D) models of a bone‑level implant system and an abutment were created by using the standard tessellation language (STL) data of original implant components. Combinations included of abutment materials i.e., Titanium (Ti), Polyetheretherketone (PEEK), Polyetherketoneketone (PEKK), Polymer infilterated hybrid ceramic (TZI) along with different restoration materials Monolithic Zirconia (MZ) and lithium disilicate glass ceramic (IPS e‑max). In each model, the implants were loaded obliquely (150 N). The stress distribution in the implant, Abutment and peripheral bone was evaluated through the von Mises stress analysis.

Higher stresses were found on neck of implants irrespective of abutment material and restorative material. Highest stress was found with PEEK material. The pattern of stress distribution in implant and peripheral bone was similar in all models.

There is no difference in stresses with the change in restorative material but the change in abutment material has effect on stresses on implants.

Patients undergoing head‑and‑neck radiotherapy are susceptible to Candida colonization and infection. This study aimed to identify oral Candida species type (ST), colony count (CC), and oropharyngeal candidiasis (OPC) in head‑and‑neck cancer patients, undergoing radiotherapy, before and 2 weeks after radiation.

In this quasi‑experimental study, head‑and‑neck cancer patients undergoing radiotherapy (up to 6000 cGy) were recruited. Samples were taken before and 2 weeks after radiation therapy (RT). CC was assigned using Sabouraud dextrose agar culture medium and morphological studies were performed to confirm OPC. For identification, polymerase chain reaction–restriction fragment length polymorphism was performed. Data were analyzed using Chi‑square‑test and kappa coefficient. P < 0.05 was considered statistically significant.

Twenty‑one of 33 patients were Candida positive. The detected fungal species included Candida albicans (60%), Candida tropicalis (22%), Candida glabrata (9%), and other species (9%). Following RT, OPC and CC changed significantly (P = 0.003 and P = 0.001, respectively), whereas ST did not significantly change (P = 0.081). Two new species (Candida krusei and Candida parapsilosis) were detected after the intervention. The OPC, CC, and ST changes after RT were not significantly related to malignancy site or radiation dose (P > 0.05).

The present study showed that OPC, CC, and ST were not related to the malignancy site. Following RT, OPC and CC changed significantly, while ST showed no significant change. The radiation dose and malignancy site had no effects on the OPC, CC, or ST alterations following RT.

Children with attention‑deficit/hyperactivity disorder (ADHD) are more prone to tooth decay. In this regard, parents, especially their mothers, play a major role in the oral health of their children.

The present study was a cross‑sectional descriptive study. The population of this study was 64 children with ADHD referred to pediatric psychiatric clinics in Isfahan. Inclusion criteria include willingness to participate in research. At least 6 months has passed since their child was diagnosed with the disorder and their child is receiving treatment.Lack of obvious physical disorders, psychotic disorders, mental retardation and chronic diseases in children with attention deficit/hyperactivity disorder with the approval of a psychiatrist. Collaboration for dental examination by a dentist. Exclusion criteria include obvious physical and mental disorders in mothers of children with attention‑deficit/ hyperactivity disorder. Simultaneous participation in a study similar to the present study due to the possibility of errors in the results. Dissatisfaction with participating in the study and leaving the study during the study. The data collection tool was interview‑questionnaire‑examination. Clinical interviews were conducted using the Kiddie Schedule for Affective Disorders and Schizophrenia to confirm ADHD and rule out other psychiatric illnesses. Information on decayed, missing, and filled teeth (DMFT) of permanent teeth and dmft of deciduous teeth is recorded separately. The score of each index (D, M, F), (f, m, d) as well as the total index (DMFT),(dmft) is calculated for each person. Data were entered into SPSS software version 26 by descriptive statistical methods, one‑way analysis of variance, t‑test, and calculation of Spearman correlation coefficient. P < 0.05 was considered statistically significant.

The oral health status of children with ADHD did not show a significant relationship with the total score of attitude and knowledge of oral health behaviors of mothers (P > 0.05). The results showed a significant positive relationship between the level of knowledge of the participants and their education level (P < 0.05).

The results revealed that mothers’ knowledge and attitude about oral health and dental health of children with ADHD were generally at an undesirable level.

Dental caries is a disease which is caused by the acidic by‑products of the metabolic processes of dental plaque. Silver components are one of the clinical solutions to prevent caries. This study aimed to investigate the effect of silver diamine fluoride (SDF) application on the shear bond strength of glass ionomer to primary teeth enamel.

In this in vitro study, a total of 48 anterior sound primary teeth were randomly divided into four groups (n = 12). The control group (G1) consisted of healthy primary teeth, and the three experimental groups (G2–G4) were composed of demineralized primary teeth. The second group did not undergo SDF treatment, the third group underwent SDF treatment, and the fourth group underwent SDF treatment plus polishing. Glass ionomer cylinders were bonded to all specimens and subsequently tested by a universal testing machine to measure the glass ionomer shear bond strength. The type of fracture was examined by a stereomicroscope. Data analysis was carried out using the SPSS 22 statistical software. Data were analyzed by one‑way analysis of variance and posthoc Tukey tests (α =0.05).

The mean shear bond strength of the glass ionomer was significantly higher in the control group than in the other three groups (P < 0.05). The mean shear bond strength of glass ionomer was significantly higher in the SDF‑treated group than in the non‑SDF treated and SDF‑treated and polished groups (P < 0.05).

Although the glass ionomer bond strength to sound enamel was higher than other groups by a significant margin, the application of SDF increases the shear bond strength of the glass ionomer to remineralized white spot enamel in primary teeth.