sima shahabi

Due to the increasing prevalence and high mortality rate of oral squamous cell carcinoma (OSCC) and problems with its routine treatments, more recent modalities like photodynamic therapy (PDT) have been developed. PDT effectively destroys tumor cells with minimum side effects. Research on in vitro effects of PDT may be helpful in determining the molecular mechanisms responsible for its effectiveness and can lead to the development of more efficient techniques. The aim of this study was to review the use of PDT in OSCC among in vitro studies.

A literature search for English articles on PDT in OSCC was performed in PubMed, Scopus, Google Scholar, and Web of Science. Data were extracted based on the inclusion/exclusion criteria, which were detailed using the PICO framework: all eligible in vitro studies evaluating the effects of PDT on the viability of OSCC compared to controls without PDT were included.

Forty-one out of 567 studies were selected. The tongue was the most common OSCC site, 5-aminolevulinic acid was the most used photosensitizer (PS), cell viability/toxicity and apoptosis were the most evaluated outcomes, and lasers with wavelengths of 600-700 nm were the most common light sources and wavelengths respectively.

PDT showed promising effects on reducing the viability of OSCC cells. Cell lines from various sources or even those originating from the same location sometimes responded differently to the same protocol. Considering the favorable results obtained from natural PSs and regarding their additional health-promoting properties, their use in future investigations with different cell lines and light specifications is recommended.

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.

The aim of this study was to assess the microtensile bond strength of three universal adhesives to dentin and enamel.

Sixty extracted human third molar teeth were chosen and divided into six groups regarding the adhesive (G-Premio Bond, Clearfil S3 Bond or Single Bond) and tooth surface. All the applied bonding agents were universal adhesives. The teeth were polished and the adhesives were applied; then the teeth were restored with composite resin. The samples were mounted in acrylic resin and sectioned. The specimens were subjected to a universal testing machine and the microtensile bond strength was measured. The failure mode of each specimen was determined under a stereomicroscope. Data were analyzed using two-way ANOVA (α=0.05).

The microtensile bond strength of G-Premio Bond to enamel and dentin was 11.79±8.27 and 17.55±9.47 MPa, respectively which was not significantly different from the values in Single Bond group (15.59±10.66 and 17.19±10.09 MPa to enamel and dentin, respectively; P>0.05). However, the values for Clearfil S3 Bond were 7.11±4.23 and 7.88±8.83 MPa to enamel and dentin, respectively, which were significantly lower than the values for G-Premio Bond (P<0.05). Scanning electron microscopic (SEM) images showed that the adhesive failure was dominant in both enamel and dentin groups and in all adhesive systems.

G-Premio Bond and Single Bond provided higher microtensile bond strength compared with Clearfil S3 Bond. Universal adhesives with their acceptable performance can be applied in self-etch mode on both enamel and dentin.

This study aimed to assess the color change (∆E00) of 7 brands of denture teeth (conventional acrylic and composite teeth) following immersion in staining solutions.

Maxillary central incisor denture teeth made of 4 conventional acrylic resins (Vitapan, SR Vivodent PE, Beta Star and Crystal) and 3 composite resins (Finex, Emeral and Phonares II) were randomly divided into four groups (n=5). Denture teeth of different brands were immersed in tea, coffee, cola, and turmeric solutions. The solutions were incubated at 37°C. The baseline color of the teeth was measured using an intraoral spectrophotometer. The color of the teeth was measured after 24 h (∆E12), 1 week (∆E13), 2 weeks (∆E14), and 1 month (∆E15). ∆E00 was calculated and analyzed using one-way ANOVA. Pairwise comparisons were performed by the Tukey’s post-hoc test (P<0.05).

The color stability of all teeth was significantly affected by the solutions (P<0.001). The type of tooth and coloring solution had significant interactions at all times (P<0.05). Turmeric caused the maximum color change in all teeth after 1 month. Repeated measures ANOVA showed that ∆E00 of all teeth was significantly affected by the duration of immersion in the solutions (P<0.001).

within the limitations of this study, 1-month immersion of denture teeth in coffee, tea and cola solution altered the ∆E values; however, they were within the acceptable range, except for Beta Star. Turmeric solution caused unacceptable color change in all denture teeth even after 24 h of immersion.

Silver nanoparticles (Ag-NPs) are potent antimicrobial agents, which have recently been used in dentistry. The aim of the current study was to optimize antimicrobial activity of Ag-NPs used in preparing irreversible hydrocolloid impressions against three microorganisms of Escherichia coli, Streptococcus mutans and Candida albicans.

After assessing antimicrobial activity of the compound using disk diffusion method, three parameters of concentration of Ag-NPs (250-1000 ppm), ratio of hydrocolloid impression material powder to water (0.30-0.50) and time of mixing (20.0-60.0 s), affecting antimicrobial activity of irreversible hydrocolloid impression materials against the three microorganisms, were optimized. This combined process was successfully modeled and optimized using Box-Behnken design with response surface methodology (RSM). Decreases in colony number of E. coli, S. mutans and C. albicans were proposed as responses.

Qualitative antimicrobial assessments respectively showed average zone of inhibition (ZOI) of 3.7 mm for E. coli, 3.5 mm for S. mutans and 4 mm for C. albicans. For all responses, when the mixing duration and powder-to-water ratio increased, the circumstances (mixing duration of 59.38 s, powder-to-water ratio of 0.4 and Ag-NP concentration of 992 response) increased. Results showed that in optimum ppm, the proportion of decreases in colony numbers was maximum (89.03% for E. coli, 87.08% for S. mutans and 74.54% for C. albicans). Regression analysis illustrated a good fit of the experimental data to the predicted model as high correlation coefficients validated that the predicted model was well fitted with data. Values of R2Adj with R2Pred were associated to the accuracy of this model in all responses.

Disinfection efficiency dramatically increased with increasing of Ag-NP concentration, powder-to-water ratio and mixing time.

Broad neural circuits originate from the hypothalamic arcuate nucleus and project to many parts of the brain which are related to pain perception. Insulin receptors are found in the arcuate nucleus. Since nociception may be affected in type 1 diabetes, the present study aimed to investigate the intra-arcuate nucleus insulin role in pain perception in streptozotocin (STZ)-induced diabetic and healthy rats.

Regular insulin was microinjected within the arcuate nucleus and the pain tolerance was measured using the hot plate and the tail-flick apparatus in diabetic rats.

The results showed that the arcuate nucleus suppression with lidocaine could increase thermal nociception in non-diabetic animals. Also, insulin within the arcuate nucleus decreased the acute thermal pain perception in these animals. STZ-induced diabetes produced hypoalgesia which the latency of these tests, progressively increased over time after induction of diabetes. Also, in the same animal group, intra-arcuate injection of insulin reduced the latency of nociception.

Intra-arcuate insulin has paradoxical and controversial effects in healthy and diabetic rats’ nociception. These effects seem to be due to the insulin effect on releasing pro-opiomelanocortin and its deriv

  Bonding of zirconia to resin cement is challenging, and the zirconia surface requires surface treatment to yield an acceptable bond strength. This study aimed to evaluate the effect of different surface treatments on the bond strength of zirconia to a resin cement. In this in-vitro experimental study, 60 zirconia discs measuring 12 mm in diameter and 2 mm in thickness were randomly divided in to six groups of 10: (I) No treatment, (II) sandblasting plus neodymium-doped yttrium aluminum garnet (Nd:YAG) laser (1 W), (III) sandblasting plus Nd:YAG laser (2 W), (IV) Nd:YAG laser alone (1 W), (V) Nd:YAG laser alone (2 W), and (VI) sandblasting. Using a custom-made punch, a V-shaped bonding area with a 4-mm diameter and 90° angle was created in a Teflon tape. Composite cylinders (Filtek Z250) were then fabricated and bonded to conditioned zirconia ceramic using Clearfil self-adhesive lut-ing cement. Specimens were stored in distilled water at 37°C for 24 hours. Then, the specimens were tested for bond strength using a universal testing machine. Data were analyzed using two-way analysis of variance (ANOVA) followed by t-test. One-way ANOVA and Tukey's HSD (honestly significant difference) test were applied for evaluating the effect of the laser. Sandblasting caused a significantly higher bond strength compared to other methods (P=0.00). Among the laser-irradiated groups, Nd:YAG laser (2 W) yielded a higher bond strength (P<0.05). Sandblasting of high-strength zirconia ceramic can significantly increase its bond strength, but no significant difference in bond strength was noted in the laser-irradiated groups

Nowadays, the electromagnetic field-emitting devices are used routinely in our lives. Controversial reports exist concerning the effects of mobile radiofrequency (RF) on different parts of the body, especially stress hormones. The main goal of the present work was to study the long-term effects of mobile RF900 MHz exposure with special focus on the adrenal gland pathophysiology and function. Adult male Wistar rats were exposed to mobile RF 6 hr daily for 4–8 weeks. Intact and switched-off exposed animals were considered as controls. Plasma ACTH and cortisol levels were measured by the ELISA method. At the end of the experiment, a histological study was done on adrenal gland and brain tissues by hematoxylin and eosin staining. The thickness of the fasciculate layer of the adrenal gland, and its cell count and perimeter were measured using the Fiji software. Enhanced plasma ACTH and cortisol levels were found after prolonged exposure to mobile RF. The fasciculata layer of adrenal cortex eventually thickened following mobile RF radiation. While the number of cells in zona fasciculata remained constant, the cell size and perimeter increased during RF exposure. Finally, we found that vacuolization in brain tissue and the number and size of vacuoles considerably increased during two months of RF exposure. Cell phone RF exposure induced significant hormonal and structural changes in adrenal gland and brain tissues. Therefore, the public should be aware and limit their exposure as much as possible

Enterococcus faecalis (E. faecalis), an infecting microorganism of the root canals, is difficult to eliminate during endodontic therapy. In this study, the effect of root canal disinfection with sodium hypochlorite (NaOCl) and chlorhexidine (CHX) was evaluated on planktonic and biofilm forms of E. faecalis in comparison with antimicrobial photodynamic therapy (aPDT) as an alternative strategy for root canal disinfection.
In this study, E. faecalis (ATCC 29212) was used. The experimental procedures included aPDT with curcumin (CUR) and indocyanine green (ICG) as photosensitizers, irrigation with 5.25% NaOCl, 0.2% and 2.0% CHX solutions as traditional endodontic irrigating solutions, and the control group. The antibacterial and anti-biofilm potentials were assessed by counting the colony forming units and also using the crystal violet assay, respectively.
According to the results, E. faecalis biofilm was disrupted by 65.3%, 81.0% and 92.6% using 0.2% CHX, 2.0% CHX, and 5.25% NaOCl, respectively (P APDT has a high potential for elimination of E. faecalis and is almost equivalent to NaOCl and CHX. It can be used as an adjucnt to conventional endodontic irrigating solutions.

T Laser irradiation of dentin surface can affect its surface topography and roughness. Atomic force microscopy (AFM) is among the most efficient tools for determination of surface topography of natural biomolecules in nano-scales. Surface roughness affects plaque retention especially in the cervical region. This study aimed to assess and compare the obstruction of dentinal tubules and dentin surface roughness after irradiation of erbium: yttrium aluminum garnet (Er:YAG )and CO2 lasers for treatment of dentin hypersensitivity (DH) .
Five disc-shaped samples measuring 3 mm in thickness were fabricated by horizontal sectioning of the cervical area of five extracted human molars using a low speed saw. Each disc was divided into 3 segments by a bur under water coolant. The three segments of each disc were placed on a glass slide. First segment: No intervention (control group). Second segment: Er:YAG laser irradiation (2940 nm, 50 mJ, 10 Hz and 0.5 W, 30 seconds) along with water coolant. Third segment: CO2 laser irradiation (10600 nm, 80 Hz, 0.3 W, 30 seconds) along with water coolant. After that, the surfaces underwent non-contact AFM. The diameters of dentinal tubules as well as surface roughness were then measured and statistically analyzed using repeated measures ANOVA.
The surface roughness parameters (Ra, Rq) showed increased roughness after laser irradiation and this increase in roughness after Er:YAG laser application was significant compared to the control group (P = 0.048). However, CO2 laser caused no significant change in surface roughness. Also, after Er:YAG laser application, fewer open dentinal tubules were observed and the remaining open tubules had a smaller diameter.
Based on the results, Er:YAG laser irradiation obstructs the dentinal tubules and increases the dentin surface roughness. This increase in surface roughness can cause microbial plaque retention and increase the risk of caries and periodontal disease. Application of CO2 laser (compared to Er:YAG) lead to slight but clinically significant obstruction of dentinal tubules and surface roughness

This study sought to assess the effect of Er,Cr:YSGG laser power on the surface roughness of lased radicular dentin using atomic force microscopy (AFM).
Fifteen human radicular dentin samples were randomly divided into five groups: one control (G1, intact) and four experimental groups treated with 0.25W (G2), 0.5W (G3), 0.75W (G4) and 1W (G5) powers of Er,Cr:YSGG laser (2.78µm) at a repetition rate of 20 Hz, with a 600-µm-diameter sapphire tip. After irradiation, surface topography was analyzed by AFM using a Si probe in tapping mode. Quantitative information concerning the arithmetic average roughness (Ra) and quadratic mean roughness (Rq) was obtained from three 5×5µm areas of each sample. The data were analyzed using one-way ANOVA (P The Ra and Rq values increased in G2 and G5 and decreased in G3 and G4 groups compared to the control group. The maximum Ra and Rq values were noted in G5, which were significantly higher than the corresponding values in G3 (P No direct correlation was found between Er,Cr:YSGG laser power and surface roughness of lased radicular dentin. Laser therapy with a mean power of 0.5W and 1W caused the lowest and highest surface roughness, respectively.

Synaptosomes are sealed particles that contain mitochondria, cytoskeleton and vesicles which are necessary to synaptic events like neurotransmitter release and uptake in the nervous system. However, the effect of high and low temperatures on synaptosome membrane integrity and function during a time course after its extraction is less known. The purpose of this study was to assess synaptosome viability and function at 37, 4°C and room temperature (RT) during 6 hours after its extraction.
Hippocampi of 40 male Wistar rats were used for synaptosome preparation. To ensure synaptosome membrane integrity and function, lactate dehydrogenase activity (LDH) and GABA uptake were assessed during 6 successive hours after their extraction at 37, 4°C and RT.
Our results showed that at 37°C, synaptosome membrane integrity was reduced 3 hours but at 4°C and RT, it occurred 5 hours following their extraction. The results of synaptosome function analysis coincide with LDH enzyme assay data, meaning that GABA uptake faced a 50% reduction from the initial value at 37°C after 3 hours and at RT after 5 hours. We also found that GABA uptake was reduced at 4°C in the first hour after extraction because the low temperature inhibits GABA transporters.
Synaptosomes preserved their viability and function at RT, 37 and 4°C at least for 3 hours after extraction and reduced over time. For long term application of synaptosomes, it is better to keep them at 4°C.

Nowadays, a new technique such as photodynamic therapy (PDT) is used to achieve effective root canal disinfection and eliminate Enterococcus faecalis as the most prevalent species associated with secondary endodontic infections and treatment failures. Employment of an optimized nontoxic photosensitizer (PS) such as indocyanine green (ICG) is a crucial part of this technique; the current study aimed at improving ICG photodynamic properties through conjugation of ICG into nano-graphene oxide (nGO) as a new PS, to evaluate the antimicrobial effects of nGO/ICG against E. faecalis.
The nGO was synthesized based on the modified Hummer method and then, direct loading of ICG onto its surface. The nGO formation was evaluated using the scanning electron microscope (SEM). The antimicrobial effect of nGO/ICG-PDT against E. faecalis was assessed by counting colony forming units (CFUs).
Results and The SEM analysis confirmed successful synthesis of nGO. The nGO/ICG-PDT at an incorporated concentration of 400 µg/mL ICG with irradiation at an energy density of 31.2 J/cm2 showed significant reduction in the number of E. faecalis higher than PDT based on ICG (1000 µg/mL) (P

Statement of problem: The bonding of fiber post to resin core or root dentin is challenged by limited penetration of resin material to the polymeric matrix of fiber posts.
The purpose of this study was to investigate the effect of Er,Cr:YSGG on micro push-out bond strength of glass fiber posts to resin core material.
We used 2 commercially available fiber posts, Exacto (Angelus) and White Post DC (FGM), which had similar coronal diameters. Specimens of each fiber post (n=36) were randomly divided into three subgroups (n=12 posts per group) according to different surface treatment control (no surface treatment), irradiation by 1W Er,Cr:YSGG, and irradiation by 1.5W Er,Cr:YSGG. A cylindrical plastic tube was placed around the post. Resin core material was filled into the tube and cured. Coronal portions of the posts were sectioned into 1-mm-thick slices. Then, the specimens were subjected to a thermocyling device for 3000 cycles. The micro push-out test was carried out using a Universal Testing Machine. Data were analyzed using one-way ANOVA followed by Tukey’s HSD post hoc test to investigate the effect of different surface treatments on each type of fiber post.
The 1.5W Er,Cr:YSGG laser statistically reduced micro push-out bond strength values in the Exacto groups (P0.05). Mode of failure analysis showed that mixed failure was the predominant failure type for all surface treatment groups.
The beneficial effect of Er,Cr:YSGG laser application could not be confirmed based on the results of this in vitro study. Er,Cr:YSGG laser could not significantly enhance the bond strength values. However, the 1.5W laser statistically decreased micro push-out bond strength in the Exacto fiber posts.

The demand for esthetic dental treatments is increasing in recent years mainly due to improved oral hygiene and better maintenance of oral health and teeth in older individuals. Bleaching of discolored anterior teeth is the most popular among esthetic dental treatments. Even individuals with sound teeth and adequate esthetics seek to have whiter teeth in the anterior region. The aim of this study was to evaluate tooth color changes following conventional in-office bleaching techniques compared to light-activated methods using different light sources.
Seventy sound anterior teeth (devoided of caries and/or fracture), extracted for periodontal and orthodontic reasons were selected and allocated to 7 groups: (A) control, (B) conventional bleaching (C) LED-activated bleaching, (D) KTP laser-activated bleaching, (E) diode laser-activated bleaching, (F) Nd:YAG laser-activated bleaching and (G) CO2 laser-activated bleaching. Colorimetric evaluation was carried out before and after treatment using a spectrophotoradiometer. Data were analyzed by one- and two-way analysis of variance (ANOVA) as well as multiple comparison methods.
The results showed that all bleaching procedures were effective in reducing the yellowness index. However, the KTP laser-activated bleaching was significantly more effective than the other techniques in 95% confidence level. It was also seen that CO2 laser activated method has outperformed groups E, F and G and the conventional bleaching without light activation was not effective at all and represented similar results with the control group. Furthermore, the groups E and G had almost the same results in decreasing the yellowness index.
The results showed that all bleaching techniques were effective however, the KTP laser-activated bleaching was significantly more efficient, closely followed by the CO2 laser-activated bleaching technique.

Although dental caries is a preventable disease, it is still common and remains a public health problem. One of the potentially effective preventive measures is laser irradiation. Raman spectroscopy is a powerful technique for studying the microcrystalline structure of dental enamel. The study assessed the chemical alterations occurring in enamel irradiated with Er:YAG or Nd:YAG lasers, by means of FT-Raman spectroscopy.
Material and Fifteen freshly-extracted human molars were treated as follows: no treatment in group A (n=5); 10 seconds irradiation with Er:YAG laser at 4 mm from the tooth surface, under water and air spray, in group B (n=5); 10 seconds irradiation with Nd:YAG laser, at 1 mm from the tooth surface, with 300 µm fiber used in a sweeping motion, in group C (n=5). After treatment, specimens were analyzed by FT-Raman spectroscopy.
Analysis of the carbonate content in terms of the integrated area under the curve (1065/960cm–1) showed a statistically-significant reduction in the integrated area ratio, in both laser-irradiated groups. The integrated area of organic content (2935/960 cm-1) showed a statistically-significant reduction after laser irradiation, in both irradiated groups.
The results show that laser irradiation affects both mineral and organic matrix of dental enamel, and may thus be a suitable strategy for caries prevention; the FT-Raman technique appears appropriate to detect such compositional and structural changes.

According to a popular Iranian belief, Camphor can not only suppress libido but also decrease the function of the reproductive system. In this regard, this study was conducted to evaluate the role of Camphor in the number of embryos in mice.
In this study, 40 male and 80 female albino mice, weighing 30-35 g, were randomly divided into 8 groups, including a control group, a sham group that received the vehicle only (olive oil), and six experimental groups that received Camphor. Three experimental groups received camphor by p.o. (gavage) and the other three experimental groups received camphor by i.p. (intraperitioneal) in doses of 10, 20, and 40 mg/kg for 15 days. Mating was confirmed after coupling a male with a female mouse. Vaginal plaque was also considered for mating. Embryos were examined during the period of gestation.
The mean number of embryos in control, sham, and received Camphor (10, 20, and 40 mg/Kg) by o. p. were 9.7 ± 4.6, 7.3 ± 4.3, 9.9 ±4.7, 8.6 ± 5.2, and 8.3 ±4.8, respectively. The mean number of embryo in received Camphor (10, 20, and 40 mg/Kg) by i. p. were 7.6 ± 5.4, 8.3 ± 3.4, and 7.3 ± 6.2, respectively. There were no significant differences in the number of embryos between control, sham, and experimental groups in both groups.
Further investigations with more focus on the effect of Camphor on sexual behavior in mice need to be carried out.

Many neurotransmitters such as arginine, vasopressin and oxytocin are involved in learning and memory processes. These neurotransmitters are synthesized by paraventricular and supraoptic nuclei (PVN and SON) of hypothalamus. The present study was conducted with the purpose of investigating the effects of PVN on memory acquisition and retrieval in a passive avoidance task. In the present experimental study, adult male Wistar rats weighing 200-250 g were randomly divided into sham (without any treatment), control saline and lidocaine groups of seven. Cannulation was performed by stereotaxic method. To inactivate the PVN, 0.5 µl of 2% lidocaine was microinjected into the nucleus through the cannula using the Hamilton syringe. Behavioral studies were done to assess the acquisition and retrieval memory using shuttle box, and the step through latency (STL) was recorded. Data analysis showed that no significant differences were found in STL (P>0.05) between the group receiving lidocaine and the other two (the sham group and the saline group) during the acquisition phase, but retention test results showed significant reduction in STL in the group receiving lidocaine (18.14±3.8) compared to the sham group (31.14±11.7) and the saline group (33.7±12.1) (p=0.03 and p<0.01, respectively). The results of the study indicated that the PVN may be involved in the retrieval of learning, whereas the given nucleus seems to have no important role in the acquisition of learning and memory.

In order to achieve a long-lasting effect, one of the main goals in root canal treatment is to eliminate the endodontic bacteria. Conventional chemomechanical debridement is considered as the basic treatment in root canal therapy, but adjunctive techniques such as antimicrobial photodynamic therapy (aPDT) can also be helpful. The aim of this study was to evaluate reports in the scientific literature that used different photosensitizers (PSs) for bacterial reduction. The literature search was conducted using databases including PubMed, Scopus, and Google Scholar with the keywords “photodynamic therapy,” “antimicrobial photodynamic therapy,” or “photoactivated disinfection” and “endodontic,” “Enterococcus faecalis,” or “root canal treatment,” from 2000 to 2015. By evaluating different studies, it was concluded that aPDT should be applied in combination with conventional mechanical debridement and irrigants. However, it is also important to note that the success rate is critically dependent on the type of the PS, output power of the laser used, irradiation time, pre-irradiation time, and type of tips used.

The main goal in endodontic treatment is to eradicate or at least reduce intraradicular microbial population to levels that are more compatible with periapical lesions healing process. Since endodontic infections are polymicrobial in nature, intraradicular survival of endodontic microbiota and their pathogenic properties are influenced by a combination of their virulence factors. The purpose of this article is to review the endodontic microbiota and their respective virulence attributes, as well as perform a literature review of the effects of disinfection procedures in the treatment of endodontic infections to gain best practices. Conventional technique for root canal preparation includes mechanical debridement and application of antimicrobial irrigants. Recently, laser irradiation has been used to enhance the results of root canal treatment through its thermal effect. To reduce thermal side effects, laser activated irrigation (LAI) and photon induced photoacoustic streaming (PIPS) were introduced. Antimicrobial photodynamic therapy (aPDT) by photochemical reaction uses light at a specific wavelength to activate a nontoxic photosensitizer (PS) in the presence of oxygen to produce cytotoxic products. Different PSs are used in dentistry including methylene blue (MB), toluidine blue O (TBO), indocyanine green (ICG) and curcumin. Among different options, ICG could be the best choice due to its peak absorption at wavelength of 808 nm, which coincides with the commercial diode laser devices. Also, this wavelength has more penetration depth compared to other wavelengths used in aPDT.

The aim of this study was to evaluate the composite surface treated by different powers of Erbium-Doped Yttrium Aluminum Garnet (Er:YAG) laser in comparison with bur preparation via scanning electron microscope. Fourteen composite resin blocks with 15× 10 × 10 mm dimensions were used in this study. The samples were divided to seven groups as follow: Group 1 (power: 1 W, Energy: 50 mJ); Group 2 (power: 2 W, Energy: 100 mJ); Group 3 (power: 3W, Energy: 150 mJ); Group 4 (power: 4 W, Energy: 200 mJ); Group 5 (power: 5W, Energy: 250 mJ); Group 6 (power: 6 W, Energy: 300 mJ); Group 7: Diamond bur. Then, the samples were prepared for SEM examination. The surface treated by Er:YAG laser showed irregular and micro porous surface. It seems that composite surface treatment by Er:YAG laser can be an alternative method for composite repair if suitable parameters are used.

Debonding of denture teeth from the denture base can be frustrating for both clinician as well as patient. The aim of this study was to determine the effect of different tooth preparations on the tensile bond strength of composite denture teeth to acrylic denture base material. In this experimental study, 108 anterior Glamour teeth were selected and divided into 9 groups, based on their preparation (physical: no physical change, glaze removal, creating two slots with 1.5 mm depth, creating a hole with 2.5mm depth, chemical: (without chemical materials, monomer, silane). Specimens were prepared and tested according to the methods of the International standards organization (ISO 20795-1). After attachment of teeth to acryl, the tensile bond stregth test was performed in a Universal Testing Machine (UTM) with a crosshead speed of 1mm/min and specimens were subjected to tensile force until failure. Data were analyzed with one-way ANOVA, Tukey HSD and Two-way ANOVA. There were significant differences between the bond strength of tested groups (P=0.012). Based on Tukey test, there was a significant difference between monomer/without physical change group and without/without (P<0.001) and control group. No significant differences were found between the bond strengths of the other groups (P=0.17). All specimens were debonded as cohesive failure. Application of monomer on the ridge lap surface led to improve the tensile bond strength between glamour composite denture teeth and Iranian acrylic resin, however physical changes were not effective. According to the cohesive failure of all the specimens, it can be concluded that the bond strength between this type of teeth and acrylic resin was stronger than the strength of teeth.

Indirect composites are developed to overcome the shortcomings of direct composites but, the adhesion of resin cements to indirect composites is still difficult.The purpose of this study was to evaluate the surface morphology of indirect resin composite treated by different powers of Er:YAGlaser using Scanning Electron Microscopy (SEM). indirect resin composite blocks (GC Gradia DA2, Japan) with 15× 10 × 10 mm dimensions were made according to manufacturer''s instructions (n=7). The bonding surface of these blocks were polished, then the samples were divided to seven groups as follow: Erbium-Doped Yttrium Aluminum Garnet (Er:YAG)laser with output power of 2, 3, 4, 5, 6,7 W (frequency of 20 Hz, very short pulse) and no treatment. Then, the surfaces were evaluated by scanning electron microscope. The surface treated by Er:YAG laser showed a porous surface. But the amount and pattern of these irregularities differ in each group which may produce micromechanical retention compared to control group with no treatment. Er:YAG laser can be used as an alternative technique for surface treatment and roughening of indirect resin composites.

In some traditional therapies, it has been claimed that camphor (a crystalline ketone obtained from cinnamomum camphora) would be a suppressor of sexual behaviors and sex hormones. This study evaluated the effects of camphor on sex hormones, like luteinizing hormone (LH), follicle-stimulating hormone (FSH) and testosterone. In this experimental study, 56 male rats were divided into 5 groups, including control (n=12), sham (n=11) and three treatment groups (n=11) in three different doses. The sham groups received daily intra peritoneal (IP) injections of the vehicle (ethanol 10%) for 30 days. Three treatment groups received different daily IP injections of the camphor (1, 2 and 5 mg/Kg) for 30 days and the control groups didn’t received anything. Serums were used for assaying LH, FSH and testosterone. The level of LH significantly increased in all doses of camphor among the treatment groups as compared to the control (p<0.05), but camphor in doses 2 and 5 mg/Kg significantly reduced the FSH level as compared to control group (p<0.05). No significant changes were seen in testosterone levels. Camphor increased level of LH, decreased level of FSH, whereas it failed to change level of testosterone. The claim of inhibitory effect of camphor on sexual activity could not be confirmed by this study. More investigations in this field are suggested.

Indirect composites are designed to overcome the shortcomings of direct composites such as polymerization shrinkage and low degree of conversion. But، good adhesion of resin cements to indirect composites is still difficult. This research was designed to assess the effect of different powers of Er; YAG laser compared with sandblasting. On the micro tensil bond strength of resin cement to indirect composites. Specimens were prepred using dental resin composite (Gradia GC) and metallic mold (15×5×5 mm) and were cured according to the manufacturer’s instructions. 24 blocks were prepared and randomly divided into 12 groups. G1: no treatment (as control)، G 2-6: Er; YAG laser irradiation (2، 3، 4، 5، 6 Watt)، G7: sandblast. Two composite blocks were bonded to each other with Panavia F. 2. resin cement. The cylindrical sections with dimensions of 1 mm were tested in a microtensile bond strength tester device using 0. 5 mm/min speed until fracture points. Data were analyzed using 2-way ANOVA and T-test. Interaction between lasers irradiation and sandblast treatments were significant (P<0. 05). Thus، T-test was used for comparing laser groups. T-test showed that when using laser with energies less than 150 mJ، there was no significant difference (P>0. 05) whether samples were sandblasted or not. Samples which received 300 mJ of laser showed lower bond strength compared with no laser treatment. Other groups showed no significant difference (P>0. 05). It seems that application of sandblast with proper variables، is a good way to improve bond strength. Laser application had no influence in improving the bond strength between the indirect composite and resin cement.