Journal of Dental Materials and Techniques
Volume:11 Issue: 1, Winter 2022

The use of nanotechnology in the field of dentistry has received assiduous attention in recent years. This technology has led to notable advances in materials science and biotechnology. Moreover, the use of nanotechnology has enabled dentists to overcome the limitations of current treatment plans and improve medical services. Several branches of dentistry have benefited from the advancement of this technology. Therefore, the present study aimed to provide readers with various types of nanotechnology used in dentistry, along with their advantages and disadvantages.

A query was carried out on PubMed and Google Scholar databases for the articles published from 2000-2022 using the keywords of Nanotechnology, Nanomaterials, Nanocomposites, Nano metals, and Nanorobots. Finally, 83 relevant articles which focused on "Nanotechnology in Dentistry" were selected and explored.

As evidenced by the obtained results, a combination of nanotechnology and dentistry provides multiple substantial benefits, including aiding in treatment improvement, pain reduction after treatment, cell surgery, more durable dental restorations, and greater patient satisfaction. Therefore, more success and fewer treatment failures are expected in all branches of dentistry with the expanded application of this science.

Evidence shows that people from different regions have different teeth characteristics based on their daily water consumption. This exploratory study aimed to measure the mineralization potential of mineral water and fresh milk on the demineralized enamel surface. The enamel surface was softened for 10 min in 100 ml of 1% citric acid under 150 rpm agitation in all specimens. Afterward, the specimens were mineralized with 100 ml of mineral water and milk under 150 rpm agitation. The mineral content of the enamel surface before and after the treatment in nanoscale was measured using an energy-dispersive X-ray spectrometer (EDXS). Before and after treatment, the results of EDXS were analyzed using a one-way ANOVA test. The results showed that initial treatment with citric acid significantly increased the surface roughness of the enamel surface. Moreover, in treatment with fresh milk, the potassium and sodium content of the enamel surface increased. It was also reported that mineral water treatment increased the sodium content of the enamel surface. The findings suggested that milk and mineral water might slightly recover the damage induced by citric acid on the enamel surface.

This study aimed to evaluate the flexural strength (FS) of dentin replacement materials, including; fiber-reinforced composite, bulk-fill flowable composites, and resin-modified glass ionomer (RMGI), layered with nanohybrid composite (NH) at different storage times.

A total of 100 specimens were prepared (n=10) and divided into five groups depending on the dentin replacement material used, and a control group with conventional NH incrementation. Each group was further subdivided into two groups according to the time of the FS testing; 24 hours or 6 months. The specimens were subjected to a 3-point bending test till failure. The comparison between the base materials and time was made using the two-way ANOVA, while the comparison between the base materials within each time interval was made using the one-way ANOVA and the Tukey’s post hoc test. Additionally, the comparison between the immediate and aged FS within each group was made using the Student’s t-test.

After 24 hours, the resin-based, bulk-fill dentin substitutes layered with NH and the incrementally placed NH, showed a higher FS than the RMGI. However, after 6 months, all groups showed a significant decrease in FS, with the exception of the RMGI group, which showed a significant increase.

Resin-based dentin replacements showed better or similar reinforcement effects compared to conventional composite incrementation, when tested immediately or after 6 months. Aging over 6 months had a deteriorating effect on the FS of all composite resin materials, while it improved the FS of the overlying composite resin in the RMGI group

There are many anatomical maxillary premolars variants, which differ in different races. The lack of information on such variants adds to the failure of endodontic treatment. This aim of this study is to evaluate anatomy and morphology of such variants using cone-beam computed tomography (CBCT), and to evaluate dentin thickness of the buccal and lingual canals of maxillary single rooted premolars with two canals. In this in-vitro study fifty single rooted maxillary premolars with two canals were collected from medical centers in Mashhad, Iran. The number of canals was assessed using periapical radiography. CBCT was utilized to scan teeth and were evaluated within the axial section for the position of root canals with respect to outer root surfaces and canal variants based on Vertucci’s classification in apical, intermediate, and coronal sections. The smallest dentin thickness was 0.40 and 0.83 ± 0.25 mm for the apical third in mesial and distal direction, respectively. Also, the largest result was 3.10 mm for the coronal third buccal direction. The largest relative frequency of Vertucci class types was found to be type IV, while the smallest relative frequency was derived to be type III. The results revealed that seventeen cases had isthmus. Because of the thin dentin related to the mesial aspect, it is required to utilize low-taper files. It is not recommended to make use of orifice shapers.

Radiography is one of the techniques used to evaluate the quality of obturation. This study compared the quality of root canal obturation and periapical tissue using periapical and panoramic radiographs and cone-beam computed tomography (CBCT). This descriptive cross-sectional study was conducted on 138 teeth of patients referring to Tabriz Faculty of Dentistry, Tabriz University of Medical Sciences, Tabriz, Iran. The patients were in the 15-72 age range and had undergone CBCT, panoramic, and periapical x-ray examinations of their endodontically treated teeth. The patients’ periapical, panoramic, and CBCT radiographs were retrieved from the faculty archives and studied. All the images and results were studied by an endodontist and a radiologist separately. The results showed a significant difference between panoramic radiography and CBCT in identifying samples without voids. Panoramic radiographs showed the most samples without voids, and the CBCT method showed the least samples without voids (23.7% vs. 2.2%). The highest agreement in identifying the lesions was obtained between the panoramic and periapical methods. The CBCT technique showed the highest frequency (97.3%, P=0.003) of bone thickness changes in samples with lesions. Based on the results, a significant difference in the quality of root canal obturation was observed between periapical and panoramic radiographs with CBCT; however, no significant difference was observed between periapical and panoramic radiographs.

The aim of this study was to evaluate and compare the microleakage of three adhesives in class V composite restorations.

30 extracted third molars were divided into three groups based on the adhesive types. Two class V cavities were prepared on each tooth. An individual adhesive was used for bonding in each group and cavities were restored with resin composites. The specimens in each group were aged by thermal cycling and submerged in silver nitrate solution. Microleakage was assessed with a stereo microscope. Statistical analysis was performed to compare the extent of microleakage between the groups.

The microleakage of the universal adhesive G-Premio Bond was significantly lower than that of the other two bonding agents. No significant difference was found between G-Premio Bond and Iperbond Ultra (p> 0.99), although the 6th-generation adhesive Quickbond had the highest microleakage compared to the other two.

Microleakage was influenced by the type of adhesive. Lower levels of microleakage in the universal adhesives led to longevity and durability of the restoration.

A great number of Iranian military forces have sustained sulfur mustard gas exposure during the Iran-Iraq war of 1980-1988 and have survived with dental care needs. Accordingly, this study aimed to discover the prevalence of intraoral lesions and periodontal diseases associated with the percentage of being chemical veterans.

This cross-sectional study was conducted in the summer of 2009 on 40 chemical veterans. The patients were examined using dental mirrors under dental unit light, as well as a periodontal probe, to evaluate soft tissue attachment. The clinical results were then documented on medical records. Data were analyzed using the Chi-square test and two independent sample t-tests in SPSS software (version 19). A p-value less than 0.05 was considered statistically significant.

The study population was composed of 40 patients with a mean age of 50.7±9.32 years, mean pocket depth of 1.47±0.31 mm, and mean bleeding on probing of 0.35±0.24 mm. Furthermore, 55% and 27.5% of the patients had xerostomia and temporomandibular joint dysfunction, respectively. However, no significant association was found between these factors and the percentage of being veterans.

The study findings showed that 96.7% of the patients had bleeding on probing problem. The mean score of plaque index that is a practical measurement on evaluating oral hygiene was 2.06±0.99. Therefore, informing chemical veterans about their periodontal health by performing regular dental assessments by dental specialists and instructing oral hygiene seem to be this group’s need.

This study was conducted to compare three rotary files of Superfile III Denco, Sp1 Gold v taper, and ProTaper in terms of debris extrusion to find the best treatment option.

In total, 51 extracted mandibular premolars were randomly assigned to three groups (n=17). Rotary systems of Sp1 Gold v taper, Superfile III Denco, and ProTaper Universal were used in the first, second, and third groups, respectively. Canals were prepared up to the F2 file, and this process was conducted only by one operator. Moreover, an Orifice shaper specific to each group was used first, and files were removed from canals and then cleaned by wet gauze. In the preparation procedure, canals were washed to extract all debris from the canal. Eppendorf tubes were used to collect debris.

Mean debris values extruded from canals in the Sp1 gold, Superfile Denco, and ProTaper Universal files were 0.0025, 0.0008, and 0.0014, respectively. There was no significant difference among debris extruded by Superfile Denco III, SP1 gold V taper, and ProTaper Universal files (P<0.05).

All instrumentation systems cause the extrusion of debris to the apical area. According to the results of the present study, there was no significant difference among debris extruded by Superfile Denco, SP1 Gold, and ProTaper Universal files. It should be mentioned that because of variations in the study designs, the direct comparison of different studies that addressed this problem is not possible, and in vivo studies should be performed to evaluate its clinical relevance