Journal of Dental Medicine

Background and Aims: One of the important fields of dentistry is surgery for dental implants. In this field, dentistry has developed considerably in recent years amongst other fields of medicine from the perspective of digital device and software application. Surgical guides help dental surgeon for more precise, confident, easier and shorter surgery. Process of producing these tools are full digital and to somehow complex due to the application of many technical devices, software and protocols. To achieve efficiency, all participants in the workflow must be aware of all steps and data requirements for production of guides. This paper investigates the production process of surgical guide comprehensively, and also, encompass all the steps in process with details.
Materials and Methods: This review article was based on searching Google scholar and PupMed databases considering key words: Surgical Guide, Guided surgery, digital dentistry, dental CAD/CAM, Additive manufacturing. More than 90% of the references were in English language and published after year 2010.
Conclusion: Today dentistry uses many digital solutions for dairy workflow and most of these solutions are developed by engineers in various fields of knowledge. Thus, this information is essential for dentists, surgeon, clinician and laboratory technician, etc. for better collaboration and participation. Amongst, advances in surgery of dental implant have been highly significant and patients benefit from better treatment and less inconvenience. In addition, dentists do surgery more precise and easier because of considering all conditions before of surgery. Thus, it is substantial inform of all steps of production process.

Background and Aims: The aim of this study was to assess the outcome of short implants (<8 mm length) as an alternative to sinus lift surgery and placement of standard-length implants (10-12 mm length) for rehabilitation of atrophic posterior maxilla.
Materials and Methods: In this prospective clinical trial, 26 patients with 6-7 mm of residual alveolar bone height in their atrophic posterior maxilla were randomly divided into two groups (n=13). The test group received short implants without sinus lift surgery while the control group received standard-length implants after maxillary sinus floor augmentation. The bone loss was evaluated at 1 to 2 years after loading of implants on radiographies and the comparison between the two groups was done using chi-square test.
Results: At 1 year, two patients (15.4%) in the short implant and one patient (7.7%) in the standard implant group experienced bone loss (P=0.5). At 2 years, four patients (30.8%) in the short implant and two patients (15.4%) in the standard implant group showed bone loss (P=0.4).
Conclusion: At 2 years after loading, the bone loss was not significantly different around short and standard-length implants. Short implants appeared to be a suitable alternative to sinus lift surgery and placement of standard-length implants for rehabilitation of atrophic posterior maxilla. However, further studies with longer follow ups are still required to cast a final judgment in this respect.

Background and Aims: Despite patient’s demand increased for tooth color restorations, the stable bond between dentin and composite is a challenge in dentistry. Dentin protease activation is responsible for dentin-resin bond failure. The aim of this study was to determine the best pretreatment agent to inhibit matrix metalloproteinase and increase resin-dentin bond durability.
Materials and Methods: After collecting 24 intact third molars, the dentin surfaces were exposed immediately under DEJ. After acid etching of dentin rewetting was done with CHX 2%, EDC 0.3 M for 60 and water (control group). Then the adhesive (Single bond, 3M ESPE, USA) and composite (Filtek Z250 XT, 3M ESPE, USA) were applied. 48 sectioned dentinal specimens were prepared. The specimens were divided into 3 groups. Each group was divided into 2 sub groups (n=8). In half of each group, the micro tensile bond strength test was done immediately and another part half 6 months. Then, the specimens were evaluated by stereomicroscope and SEM. Statistical analysis was performed using SPSS23 software, two-way ANOVA and multiple Tukey and T-test comparisons. P<0.05 was considered as a significant level.
Results: There were not significant differences between immediate micro tensile bond strength of CHX, EDC and control groups (P=0.97). However, there was significant differences between CHX, EDC compared with the control group (P≤0.0001). Comparison between the immediate and 6-month bond strengths in each group, only in EDC group, there was no significant after 6 months’ difference (P=0.64).
Conclusion: EDC and CHX t did not have any effect on the immediate microtensile bond strength. After 6 months, EDC prevented bond strength deterioration, but the bond strength was decreased after CHX usage.

Background and Aims: The bleaching agents can lead to color and translucency changes in composite resins. Due to the increasing use of the nano composites and the silorane-based composites, this study aimed at examining the color and translucency changes of these restorations after bleaching agents.
Materials and Methods: In this experimental - laboratory study, 198 composite discs were divided into three groups of 66 specimens using three types of composite: the microhybrid composite Z250, the nanohybrid composite Z350 and the silorane-based composite P90. After acid etching, half of the specimens in each group were covered by a resin rebounding agent. Then, the color and translucency assessment was done by reflectance spectrophotometer, using CIE LAB system. Each group was divided into three subgroups of bleaching agents: the 40% hydrogen peroxide and 20% carbamide peroxide bleaching agents and the control group. After applying bleaching agents, the final color and translucency changes were assessed. Data were analyzed using Mann Whitney and Kruskal Wallis tests.
Results: The effect of composite and bleaching agent type and bonding agent were significant (P<0.001). The color changes in the microhybrid composite were higher than nanohybrid and silorane-based composites (P<0.001) (∆E>3.3). Also, the color changes by 20% carbamide peroxide were higher than that of hydrogen peroxide and control groups (P<0.001). The results of translucency changes were generally consistent with color-change measurements (∆E>3.3).
Conclusion: According to the present study, the most color changes appeared in the microhybrid composite and by 20% carbamide peroxide bleaching agent. Rebound samples were generally less affected by bleaching agents. The least color and translucency changes were related to nanohybrid composites.

Background and Aims: Erosion is the chemical dissolution of a tooth by acid without bacterial involvement. The purpose of the current study was to investigate the effect of resin infiltration (Icon), MI paste plus, and Nd:YAG laser on the enamel microhardness.
Materials and Methods: 40 enamel samples were obtained from the third molar tooth. Primary microhardness was measured in all specimens. Then, erosion was created using hydrochloride acid on the surfaces of enamel and the microhardness values were measured. The samples were randomly divided into four groups. G1: MI paste plus, G2: MI paste plus+ Nd:YA laser, G3: ICON without etching, G4: ICON with etching. Erosion was induced again by hydrochloric acid and then subjected to thermocycling. Finally, the microhardness of the samples was measured. Statistical analysis was performed using SPSS23 software, one-way ANOVA, multiple Tukey and T-test comparisons. P<0.05 was considered as a significant level.
Results: The microhardness increased in the third stage compared to the second stage in all groups, which was statistically significant (P<0.000). Also, the comparison of the increase of microhardness among groups, except second group with the fourth group, was statistically significant.
Conclusion: All the materials used in this study significantly increased the microhardness of the eroded enamel.

Background and Aims: Adding nanoparticles to dental composite resins, could reduce bacterial adhesion and secondary caries. Thermocycling can resemble in-vitro conditions to the oral environment. The aim of this study was to determine the effect of thermocycling on the microleakage of a mixture of copper oxide nanoparticles and flowable composite.
Materials and Methods: In this in-vitro study, 88 premolar teeth were divided into eight groups based on the application of copper oxide nanoparticles with concentrations of 0.1% and 0.3% w/w and thermocycling by 0, 1000, 5000 and 15,000 cycles. The occlusal grooves of the teeth were sealed with the mixture of flowable composite and copper oxide nanoparticles, and the teeth were thermocycled. Next, the teeth were immersed in methylene blue 2% solution for 24 hrs and were cut and the microleakage was evaluated by a stereomicroscope (hp/USA). Data were analyzed using Kruskal-Wallis and Mann-Whitney tests at the significance level of 0.05.
Results: In the groups with 0.1 % copper oxide nanoparticles, the mean microleakage increased significantly with increasing the number of thermocycling rounds (P=0.032). The difference in the microleakage between the groups exposed to 0 and 15,000 termocycling was significant (P=0.019). However, thermocycling had no significant effect on the microleakage of groups with concentration of 0.3% (P=0.780). The specimens subjected to the 0, 1000, 5000 and 15000 thermocycling in two concentrations of copper oxide nanoparticles showed no significant difference in the microleakage.
Conclusion: In groups containing copper oxide nanoparticles with a concentration of 0.1%, the microleakage increased by increasing the number of thermocycling up to 15,000 cycles compared to the control group. However, this did not have significant effect for the concentration of 0.3% copper oxide nanoparticles.

Background and Aims: A significant percentage of children with dental caries require, hospital dentistry and their parents do not have much information in this regard. The aim of this study was to determine the knowledge, attitude and practice of pediatricians in hospital dentistry in Isfahan Province.
Materials and Methods: This cross-sectional study was performed on 100 pediatricians working in Isfahan. The self-administered questionnaire included demographics of doctors and 19 questions for assessing the knowledge, attitude and practice of pediatric practitioners about hospital dentistry under general anesthesia. Raw data were analyzed by Chi-square test using SPSS software version 23.
Results: 100 pediatricians with an average age of 44.1±5.7 years (57% male) completed the questionnaire. 53% of the pediatricians had a high level of awareness about hospital dentistry and 42% about its related guides. 66% practitioners had a favorable attitude toward general anesthesia and costs, while 71% considered the parents' awareness were poor about hospital dentistry. Only 43% of pediatricians performed oral examinations in their daily visits, and 17% had a referral for hospital dentistry. Male pediatricians aged from 35 to 45 had a higher level of knowledge about hospital dentistry. The attitude and practice of pediatricians did not have a significant relationship with their age. Meanwhile, male pediatricians had better performance in oral and dental examination and referral for hospital dentistry (P=0.15).
Conclusion: From the results of this study, there is a need for a serious improvement in the level of knowledge, attitude, and practice of pediatricians in the field of hospital dentistry.

Conclusion: The high prevalence of TMD and related factors, such as a history of jaw dislocation, posterior edentulousness, earache, and clenching, requires attention to be identified and treat these problems.

Background and Aims: The aim of this study was to investigate the tooth discoloration caused by cold ceramic compared to MTA Angelus in contact with the washing solutions such as sodium hypochlorite (NaOCl) and normal saline.
Materials and Methods: 50 samples of extracted human maxillary anterior teeth were selected. After preparing the access cavity, they were divided into 4 experimental groups and 1 control group (10 in each group). The access cavities of teeth in groups 2 and 4 were rinsed with 5.25% sodium hypochlorite and those in groups 1 and 3 were rinsed with normal saline. Then, after drying, 3 mm thickness of cold ceramic (groups 1 and 2) and MTA Angelus (groups 3 and 4) were placed in the access cavities of the teeth. After setting of the materials, all specimens were restored with a resin modified glass ionomer. Based on the CIE Lab system, each sample’s total color change (∆E) was obtained before, one, and 90 days after application. Data were statistically analyzed using the Wilcoxon test.
Results: According to the results, there was no statistically significant difference in the average tooth discoloration between the groups filled with cold ceramic and in different time periods (P>0.05). While, in the groups filled with MTA Angelus, the difference in the average tooth discoloration in 90 days after application was significantly higher than one day (P<0.05).
Conclusion: The results of this study showed that compared to MTA Angelus, cold ceramic causes less tooth discoloration over time and therefore, it can be suggested as a more suitable alternative endodontic cement than MTA Angelus.