Dental Research Journal
Volume:20 Issue: 3, Mar 2023

Root perforation may occur at any stage of endodontic treatment and is mostly due to iatrogenic injury and may compromise the outcome of endodontic treatment. Repairing a perforation is difficult and the prognosis depends on various factors such as time, site and size of perforation, and the patient’s overall health status. Hence, choosing the most appropriate material can be critical for the dentist. In this case report of a strip‑perforation repair, an mineral trioxide aggregate‑like material (cold ceramic) that has been shown in previous studies to have favorable properties, was successfully used.

The burden of oral diseases is increasing, which constitute a major public health problem. The use of probiotics as an adjuvant, along with routine dental care practice by an individual, can produce additional benefits in the maintenance of one’s oral health. The study aimed to investigate the effect of Bifidobacterium as a probiotic on oral health.

Six databases and registers were searched from the start of the database to December 2021 without any restrictions. Randomized controlled trials (RCTs) evaluating the clinical effects of Bifidobacterium as a probiotic on oral health were included in the study. The Preferred Reporting Items for Systematic Reviews and Meta‑analyses (PRISMA) guidelines were followed to conduct this systematic review. The included studies were analyzed for the risk of bias using the Cochrane risk‑of‑bias tool for randomized trial (RoB 2) tool as well as quality of available evidence using GRADE criteria.

From the 22 qualified studies, four studies showed non‑significant results. There was a high risk of bias in 13 studies and some concerns of bias in nine studies. No adverse effects were reported, and the quality of available evidence was moderate.

The effect of Bifidobacterium on oral health is questionable. Further high‑quality RCTs are required on the clinical effects of bifidobacteria and also the optimum level of probiotic needed, and ideal mode of administration to provide oral health benefits. Furthermore, synergistic effects of the combined use of various strains of probiotics need to be studied.

Occlusal loading of osseointegrated implants is believed to be an essential determining factor in the long‑term success of an implant treatment. Numerous studies have been conducted on the evaluation of stress distribution by definitive restoration materials for Implant‑supported fixed prosthesis, but very few have evaluated provisional restoration materials for the same. This study aims to evaluate the influence of provisional restoration material – Milled Polymethylmethacrylate (PMMA) and Milled Polyetheretherketone (PEEK), over stress distribution on the peri‑implant bone around an implant‑supported three‑unit, fixed dental prosthesis using finite element analysis method.

Three‑dimensional models of a pair of bone‑level implant system and titanium base abutments were created using the standard tessellation language data of original implant components. A bone block representing the mandibular posterior area was created, and the implants were placed in the bone block with 100% osseointegration in the 2nd premolar to 2nd molar region. A superstructure of an implant‑supported 3‑unit bridge was modeled on top of the abutments, each crown to be 8 mm in height and with an outer diameter of 6 mm in 2nd premolar region and 10 mm in 1st molar and 2nd molar region. Two different models were created according to combinations of provisional restoration materials, namely, Milled PMMA and Milled PEEK based on. In each model, the implants were loaded vertically (300 N) and obliquely (150 N at 30°). The stress distribution in the cortical bone, cancellous bone, and implant was evaluated through the von Mises stress analysis.

The results showed no difference in stress distribution due to the different provisional restorations – Milled PMMA and Milled PEEK. In addition, the vertical load resulted in higher stress values in the implant components, cortical bone, and cancellous bone in both PEEK and PMMA models as compared to oblique loading.

The new polymer, PEEK was seen to provide comparable stress generation in the current study without exceeding the physiological limits of peri‑implant bone. Thus, it can be considered as a good alternative to PMMA resin as a provisional crown material since it provides certain additional benefits.

Transplantation of one tooth to another site in the same individual can be considered an attractive alternative to dental implants or fixed prostheses. This study reports the treatment results of a 16‑year‑old female with severe crowding in upper and lower arches and a fractured mandibular premolar with a poor prognosis. The crowding of the lower left quadrant was relieved by the extraction of the first premolar. This extracted tooth with a complete root was transplanted to the right quadrant with the fractured tooth. Platelet‑rich fibrin can stimulate and accelerate periodontal healing. The platelet concentrate of this patient was prepared and applied to the socket wall at the time of surgery. The acceptable occlusion and the excellent 4‑year prognosis of the transplanted tooth are presented.

Surface smoothness considered to be a significant part of the appearance and success of the restorative materials. The aim of this study was to assess the influence of four different polishing systems on surface roughness of four resin composite materials when subjected to thermocycling.

This research was designed as a comparative study. Four resin composites were used which are: Nanofill composite (Filtek Supreme XT), nanohybrid composite (Tetric EvoCeram), microfill composite (Renamel Microfill), and microhybrid composite (Filtek Z250). Sixty disk‑shaped specimens of each resin composite were prepared then divided into four groups according to the polishing system (n = 15); which were Sof‑Lex Spiral, Diatech Shapeguard, Venus Supra, and Astropol. The specimens of each group were polished following the manufactures’ instructions, then surface roughness, Ra values in µm were measured initially and after the specimens subjected to thermal cycling. The influence of resin composites, polishing systems, thermocycling, and their interaction effects on surface roughness (Ra mean values) was statistically analyzed mainly by using the repeated measures two‑way analysis of variance test, whereas the Bonferroni’’s post hoc test was applied for pair‑wise comparisons. P ≤ 0.05 was used as the significant level.

The results of this study revealed that Filtek Supreme XT recorded significantly the lowest mean surface roughness (Ra ) of 0.2533 ± 0.073 µm (P < 0.001). The Sof‑Lex Spiral polishing system revealed significantly the lowest mean surface roughness (Ra) of 0.2734 ± 0.0903 µm (P = 0.004). Regardless of composite type and polishing system, there was a statistically significant increase in mean surface roughness values (Ra ) in µm after thermocycling (0.2251 ± 0.0496 µm and 0.3506 ± 0.0868 µm, respectively) (P < 0.001).

Resin composite type, polishing method, and thermocycling aging significantly affected the surface roughness of composites; Nanofill composite and Sof‑Lex Spiral polishing system provided the lowest values of surface roughness which increased after thermocycling.

The prevalence of oral squamous cell carcinoma (OSCC) has increased in recent years. With the development of various treatments, the mortality rate has decreased and more people are living with the consequences of the disease and its treatment, which can have a great impact on the quality of life. Some questionnaires measure the impact of the disease on daily activities and patient behavior. In this study, the oral health‑related quality of life (OHRQOL) was assessed through the Oral Health Impact Profile (OHIP)‑14 questionnaire between the OSCC patient and control groups.

In this cross‑sectional study, the OHIP‑14 questionnaire was given to 51 OSCC patients who had completed the treatment at least 6 months before participating in this study and 51 healthy individuals, and we used the Chi‑square test, independent sample t‑test, one‑way ANOVA, and linear regression in three models. P = 0.05 was considered statistically significant.

The mean age of patients was 55.86 ± 15.04 years and the control group was 54.96 ± 14.08 years. Women made up 51% of patients. The mean OHIP score was 22.84 ± 11.42 in the patient group and 17.92 ± 9.23 in the control group, which indicates a significant (P = 0.005) difference between the two groups according to the independent sample t‑test.

The OHRQOL of patients has significantly decreased compared to the control group. Surgery had the lowest quality reduction, and combined surgical treatment with radiotherapy and chemotherapy had the highest reduction in the OHRQOL. It is recommended to have regular follow-up sessions and to have a proper diet during and after treatment.

Polymethyl methacrylate resin is widely used in orthodontic treatments. Graphene oxide (GO) has reactive functional groups on its surface that facilitate binding to various materials such as polymers, biomolecules, DNA, and proteins. This study aimed to investigate the impact of adding functionalized GO nanosheets on the physical, mechanical, cytotoxicity, and anti‑biofilm properties of acrylic resin.

In this experimental study, fifty samples (for each test) were divided into groups of 10, in the form of acrylic resin discs with concentrations of 0, 0.25, 0.5, 1, and 2 weight percentage (wt%) of functionalized GO nanosheets and also the control group. Samples were evaluated in terms of physical properties (surface hardness, surface roughness, compressive strength, fracture toughness, and flexural strength), anti‑biofilm properties (On four groups of micro‑organisms, including Streptococcus mutans, Streptococcus sanguis, Staphylococcus aureus, and Candida albicans), and cytotoxicity. Data were analyzed using SPSS software version 22, descriptive statistics, one‑way analysis of variance test, and Tukey post hoc test. The significance level was considered P < 0.05.

No significant difference was observed between the different groups with weight percentages of 0.25, 0.5, 1, and 2% nano GO (nGO) and the control group (without nGO) in terms of surface roughness and toughness. However, compressive strength, three‑point flexural strength, and surface hardness showed significant differences between the groups. Furthermore, the degree of cytotoxicity increased by increasing the weight percentage of nano‑GO.

The addition of functionalized nGO in appropriate concentrations to polymethyl methacrylate can improve the anti‑bacterial and anti‑fungal biofilm properties without changing or increasing their physical and mechanical properties.

Biodegradable hydrogel scaffold is one of the crucial characteristics that determine the success of pulp regeneration. The degradation should be suitable for the growth of new tissue establishment. The aim of this study is to synthesize and compare the novel biodegradable hydrogel scaffold based on hydroxyapatite (HAp) eggshell, collagen, and epigallocatechin‑3‑gallate (HAp‑Col‑EGCG) with different HAp concentrations in vitro.

This study is original research. HAp‑Col‑EGCG hydrogel scaffolds were prepared using 1:1, 1:2, and 1:4 ratios of collagen and HAp with 10 µmol/L EGCG. The samples were freeze‑dried and immersed in phosphate buffer saline containing lysozyme enzyme. The dried samples were weighed to determine the percentage of biodegradation value (P < 0.05).

The result showed HAp‑Col‑EGCG was biodegradable but it has not been concluded that it can be completely eliminated. The data were analyzed by one‑way analysis of variance and it indicated significant differences in percentage values.

Hydrogel scaffold based on HAp‑Col‑EGCG can be degraded and have the potential to be used as a biodegradable scaffold in supporting tissue regeneration.

Different studies about the effects of mouthwashes on force reduction by elastomeric chains are reported in the literature. Hence, this review was done for the assessment of force degradation in the elastomeric chains in different mouthwash compositions. This study helps to improve the clinical performance of elastomeric chains used in orthodontics, reducing force degradation, and finally assisting clinicians in choosing better and more efficient methods for their treatments.

In this review article, an extensive search was performed in the electronic databases of Cochrane Library, Web of Science, PubMed, and Scopus from the year 1990–2020. No language restriction was considered and manually investigated the reference lists of all articles related to the title. Out of 450 obtained articles, 14 in vitro studies were chosen based on the inclusion criteria, and their quality was assessed using modified CONSORT. This systematic review was limited and written based on the Preferred Reporting Items for Systematic Reviews and Meta‑Analyses protocol.

Based on the results achieved, mouthwashes containing alcohol caused considerable force degradation in the elastomeric chains compared to the alcohol‑free ones and mouthwashes with fluoride caused lesser force degradation compared to other types.

The digital dentistry, requires materials with wo opposite properties of machining ability and also enough hardness. The main objective of this experimental study was to investigate the fabrication feasibility of the lithium metasilicate glass‑ceramic in partially crystalized stated using the spark plasma sintering (SPS) method.

In this study, SPS for the first time was used to fabricate primary lithium metasilicate glass‑ceramic (LMGC) blocks. The raw materials were mixed and melted and then quenched in water and the resulted frits were grinded. The resulting powder was sintered by SPS at 660, 680, and 700°C.

Scanning Electron Microscope (SEM), X‑ray diffraction (XRD), and Vicker’s microhardness assay were used to evaluate the properties of samples. Statistical comparison of the obtained data was performed by ANOVA, followed by the post hoc test of Duncan. Microstructural studies by SEM and XRD showed that all samples were composed of lithium metasilicate phase in a glassy matrix. With increasing the sintering temperature, the number and size of lithium metasilicate particles increased and higher mechanical properties have been achieved. However, the sintered sample at 700°C has less processing ability than the samples sintered at 660 and 680°C.

The optimum sintering temperature for glass frit consolidation was determined by SPS at 680°C.

An ever‑increasing demand is seen for clear aligners and transparent vacuum‑formed retainers. They are esthetic and convenient. However, the biomaterials used in these appliances might pose biological safety and biocompatibility threats in terms of their bisphenol‑A (BPA) release, cytotoxicity, adverse effects, and estrogenic effects. Due to the controversial results and the lack of any systematic reviews in this regard, we conducted this systematic review.

Web of Science, PubMed, Cochrane, Scopus, and Google Scholar as well as references of the found articles were searched (independently by 3 researchers) up to December 22, 2021, to find studies relevant to the biocompatibility of clear aligners and thermoplastic retainers. The search keywords were a combination of the following (and more): Essix, vacuum‑formed aligner, thermoplastic aligner, clear aligner, Invisalign, vacuum‑formed retainer, BPA release, monomer release, cytotoxicity, estrogenicity, biocompatibility, chemical properties, and oral epithelial cell. As eligibility criteria, articles in all languages would be included as long as their text could be translated clearly using online translators or by professional translators; all types of publications (article, book, and thesis) would be included if containing relevant studies and information; they should have been on clear liners or thermoplastic retainers; and they should have been on biocompatibility, safety, cytotoxicity, or estrogenicity of clear aligners or thermoplastic retainers. There were no restrictions on the type of study (randomized clinical trials, experimental in vitro studies). Studies focusing merely on the mechanical properties of clear aligners or thermoplastic retainers (without examining their chemical properties) would be excluded. The risk of bias was assessed.

The risk of bias was rather low. However, the methodologies of the studies were quite different. Overall, 16 articles (1 randomized clinical trial and 15 in vitro studies) were identified. The data for BPA release were reported in four articles (1 clinical trial and 3 in vitro studies). Quantitatively speaking, the amount of released BPA reported by in vitro studies was very low, if not zero. However, the BPA level was very high in the only randomized clinical trial. Many adverse effects were linked to using clear aligners or transparent retainers, including pain and soft‑tissue issues such as burning, tingling, sore tongue, lip swelling, blisters, ulceration, dry mouth, periodontal problems, and even systemic problems such as difficulty in breathing. Besides these biological adverse effects, oral dysfunctions and speech difficulties and tooth damage may be associated with clear aligners and should as well be taken into consideration.

Given the very high levels of BPA leach observed in the only clinical trial and considering other possible dangers of small traces of BPA (even at low doses) and also given the numerous adverse events linked to clear aligners or transparent retainers, it seems that safety of these appliances might be questionable and more clinical studies of biocompatibility are needed in this regard.

Cleft lip (CL) and cleft palate (CP) are among the most common birth defects in the craniofacial region affected by various environmental and genetic factors. The prevalence of these abnormalities varies in races and countries. Therefore, it is a necessity to design a website to register newborns with CL ± CP in Iran. This study aimed to design a website to record the characteristics of children with CL ± CP.

First, a website was designed to register the characteristics of children with CL ± CP. To evaluate the accuracy of the website, the characteristics of all children (n = 31) with CL ± CP were recorded and analyzed.

Due to the capability of the website to print and create reports in Excel format, the data of registered patients were analyzed.

As CL ± CP are very common defects around the world including Iran, it is necessary to design a website to record all information about these children in Iran. Hope this website helps the public health authorities to improve program effectiveness to treat these children.

Rheumatoid arthritis(RA) is one of the most common chronic inflammatory diseases. Previous studies have reported an association between stress and salivary alpha‑amylase. The aim of this study was to investigate the concentration of salivary alpha‑amylase in patients with RA (by elimination of stress factor).

In this case–control study, we enrolled 50 patients with RA and 48 healthy patients as the control group. The perceived stress scale questionnaire was used to evaluate scores of stress in both case and control groups, and then the participants with high scores of stress were excluded from the study. Moreover, the alpha‑amylase activity kit was used for the assessment of the levels of salivary alpha‑amylase. In all analyses, the significance level was considered to be < 0.05. Finally, the obtained data were analyzed by SPSS22.

Our results indicated a high score of stress in the case group (19.42 ± 5.83 units) compared with the control group (18.02 ± 6.07 units) which was not statistically significant (P < 0.248). Moreover, we demonstrated a high salivary alpha‑amylase concentration in the case group (340.65 ± 38.04 units) compared to the control group (302.62 ± 58.72 units), which was statistically significant (P < 0.001). The sensitivity and specificity of this method, at >312 alpha‑amylase concentrations, were 80% and 46%, respectively.

In general, we indicated that the alpha‑amylase concentration in patients with RA is higher than the healthy controls, and can be used as a codiagnostic factor.

This study aimed to compare the success rate of inferior alveolar nerve (IAN) anesthesia in the mandibular first molars with symptomatic irreversible pulpitis using two anesthetic solutions of prilocaine and mepivacaine.

The current randomized controlled clinical trial was conducted on 100 patients in two groups (n = 50). Standard injection of IAN block (IANB) was performed using two cartridges of 3% mepivacaine plain in the first group and using two cartridges of 3% prilocaine with 0.03 IU felypressin in the second group. Fifteen minutes after injection, the patients were asked about lip anesthesia. In case of a positive answer, the tooth was isolated with a rubber dam. Success was defined as no or mild pain on the basis of the visual analog scale recording upon access cavity preparation, entry into the pulp chamber, and initial instrumentation. Data were analyzed with SPSS 17 using the Chi‑square test, and P < 0.05 was set as statistically significant.

The patients’ pain severities during the three stages were significantly different (P = 0.001, 0.0001, and 0.001, respectively). The success rate of IANB during access cavity preparation was 88% with prilocaine and 68% with mepivacaine. This rate during entry into the pulp chamber was 78% and 24%, respectively, which was 3.25 times higher with prilocaine than mepivacaine. The success rates during instrumentation were 32% and 10%, respectively, which was 3.2 times higher with prilocaine than mepivacaine.

The success rate of IANB in the teeth with symptomatic irreversible pulpitis was higher using 3% prilocaine with felypressin than using 3% mepivacaine.

The aim of this study was to assess the effect of incorporation of zinc oxide nanoparticles (ZnO‑NPs) to glass‑ionomer cement (GIC) (Fuji II SC, GC Corp., Tokyo, Japan) on subgingival accumulation of mutans streptococci and lactobacilli under orthodontic bands.

In order to conduct this in vivo split‑mouth study, 20 patients aged between 7 and 10 years who required lingual holding arch on their mandibular first molars were divided into two groups. In one group, Fuji II SC GIC was used for cementation of the right molar band, and the same cement containing 2 wt% ZnO‑NPs was used for the left one. The opposite was performed for the second group while the operator was blinded to the cement types. Subgingival microbial sampling was performed 16 weeks after cementation of lingual arch. Mutans streptococci and lactobacilli colony counts were compared. Paired t‑test was used to compare the two cement groups. Data were analyzed using SPSS version 21, and P ≤ 0.05 was considered statistically significant.

The mean colony counts of mutans streptococci, lactobacilli, and total bacterial count in Fuji II SC containing ZnO‑NPs were significantly lower than the corresponding values in plain Fuji II SC group.

Incorporation of ZnO‑NPs into GIC reveals antimicrobial features against mutans streptococci and lactobacilli under orthodontic bands.