Evaluation of Three Methods for the Treatment of Dentin Hypersensitivity: A Randomised Clinical Trial.

OBJECTIVES: In this study, we aimed to compare the effectiveness of Gluma and high-power 980-nm diode laser, alone or in combination, in the treatment of cervical dentin hypersensitivity. METHODS: A total of 20 patients (5 men and 15 women), aged 25 to 60 years, who met the inclusion criteria, were enrolled in this study. A total of 60 teeth were randomly divided into 4 groups: G1, 980 nm diode laser (in 2 sessions within a 1-week interval); G2, Gluma (in 2 sessions within a 1-week interval); G3, 980 nm diode laser plus Gluma; and G4: control. Thermal (cold spray) and air blast (air syringe of dental unit) stimuli were used to evaluate cervical dentin hypersensitivity in the patients. Their pain response was assessed using a visual analogue scale (VAS) before treatment (baseline), in the first treatment session (15 minutes after treatment), in the second treatment session (after 1 week), and in 2-week, 1-month, and 3-month follow-up sessions. The obtained data were analysed using non-parametric tests, including Kruskal-Wallis test, Friedman test, Mann-Whitney test, and Wilcoxon test, in SPSS Version 22 at a significance level of P < .05. RESULTS: Based on the results, there was a significant difference in the average VAS scores for cold and air blast stimuli between the 4 groups 1 month after the intervention (P < .05). Meanwhile, the laser group had the lowest VAS score for cold and air stimuli. On the contrary, no significant difference was found between the 4 groups 3 months after the intervention (P ˃ .05). CONCLUSION: The present results showed that 980-nm diode laser alone was more effective than the other 2 intervention methods for 1 month. TRIAL REGISTRATION: The study was registered in the Iranian Registry of Clinical Trials (IRCT20120901010703N5).

Comparison of shear bond strength of rebonded stainless steel brackets with three different enamel surface conditioning methods.

Background: During the orthodontic bonding process, the need for repositioning or rebonding of orthodontic brackets on the enamel surface occurs frequently. The aim of this study is to compare the shear bond strength (SBS) in rebonding orthodontic stainless steel brackets with three different methods of enamel surface conditioning methods. Materials and Methods: In this in vitro study, 80 human premolars that were extracted for orthodontic purposes were randomly divided into four groups and underwent orthodontic bonding procedure (N = 20). Except for the control group, three other groups underwent debonding and rebonding process in which after removing the remaining adhesive with tungsten-carbide bur, enamel surface conditioned by three different methods including re-etching with phosphoric acid, sandblasting + acid etching, and Erbium-doped Yttrium-Aluminum-Garnet laser. Then, the SBS of the bracket to the enamel surface was compared between different groups. Scanning Electron microscopy images were also obtained from a number of samples. Statistical analysis was performed by Kruskal-Wallis and Mann-Whitney tests. Results: The highest SBS was observed in the primary bond (control group) with an average of 29,440 MPa. There was a significant difference between the studied groups (P < 0.001) and only the group that was re-etched with phosphoric acid had no significant difference with the control group (P = 0.708) ∝ =0.05. Conclusion: Rebonding of brackets using phosphoric acid for reconditioning of the enamel surface creates bond strength comparable to the primary bond. Other groups had significantly lower SBS than the control group.

Effect of Propolis mouthwash on clinical periodontal parameters in patients with gingivitis: A double-blinded randomized clinical trial.

OBJECTIVES: Periodontal diseases have multifactorial aetiology and are primarily caused by pathogenic bacteria. Using antibacterial mouthwashes as an adjunct to mechanical plaque control can effectively improve the quality of oral hygiene maintenance at home. This study aimed to assess the clinical efficacy of a propolis-containing mouthwash in gingivitis treatment. METHODS: This clinical trial evaluated 32 patients with gingivitis in two groups (n=16). The intervention group received a mouthwash containing propolis extract while the control group received the same mouthwash without the propolis extract. The papillary bleeding index (PBI), plaque index (PI) and tooth discoloration were evaluated in each patient at baseline (before the intervention) and at 15 and 30 days, after treatment. To facilitate the follow-up evaluations, the measurements were recorded for the tooth with the most inflamed gingiva in each quadrant (n = 128). The two groups were compared using the Mann-Whitney test. RESULTS: The change in PI was 85.19 ± 51.6% in the propolis and 83.93 ± 36.1% in the placebo group with no significant difference between them (p = 0.91). The reduction in papillary bleeding index was significantly greater in the propolis group compared with the placebo group (p < 0.001). The change in tooth colour over time was significant in the placebo and insignificant in the propolis group (p = 0.14). CONCLUSIONS: Considering the current findings, it seems that propolis mouthwash can effectively decrease gingival inflammation and bleeding, without causing tooth discoloration or staining. Considering the limitations of this study such as small sample size (based on participants and also number of teeth included in the study), future studies are warranted on this topic.

Comparison of antimicrobial effect of several decontaminating methods on contaminated Titanium discs.

Background: Decontaminating the implant surface, exposed to bacterial biofilm, is a concern in the treatment of peri-implant inflammatory disease. The aim of this study was to compare the effect of several methods on reduction of the bacterial load, colonized on the surfaces of titanium discs. Materials and Methods: In this in vivo study, seven titanium discs with Sandblasted, Large-grit, acid-etched (SLA) surface were placed in the mouth of each of ten patients with chronic periodontitis by an intra-oral maxillary splint for 24 h. In each patient, the contaminated discs, except for the negative control ones, were randomly treated by one of the six antiseptic methods including sterile normal saline, plastic curette, air polisher, hydrogen peroxide, 980 nm diode laser, and Er-YAG laser. A spectrophotometer was used to measure Optical Density (OD) in case of aerobic microorganisms. Colony-Forming Units (CFUs) were used for anaerobic bacteria. Data were analyzed through Kruskal-Wallis and Mann-Whitney Tests at a significance level of α =0.05 by SPSS software. Results: Statistical analysis showed a significant decrease in OD of aerobic bacteria among the seven groups during a 0-24 h time interval (P < 0.001). Furthermore, these tests showed a significant difference in the CFU (P < 0.001) for anaerobic bacteria after 48 h. Conclusion: The results of this study showed that all of the adopted methods significantly reduced microbial colonies on the surfaces of titanium discs with SLA surface. Er: YAG laser and normal saline had the highest and the lowest effects, respectively.

Evaluation of the effects of 980 and 810-nm high-level diode lasers in treating dentin hypersensitivity: A double-blinded randomized clinical trial.

Background: Dentin hypersensitivity is a prevalent problem, manifested as a short sharp pain. Researchers have used different lasers to treat this condition. The present study aimed to evaluate the effect of 980 and 810-nm high-level diode lasers on dentin hypersensitivity to determine proper laser parameters for clinical applications. Materials and Methods: In this double-blinded randomized clinical trial, seven patients with 60 teeth affected by dentin hypersensitivity were selected for the present double-blind, randomized clinical trial. The patients' teeth were randomly matched and assigned to three groups: Group 1: 980-nm diode laser; Group 2: 810-nm diode laser; and Group 3: Control, which received only the guiding beam. The laser parameters were 1-W power, continuous wave mode, a distance of 1 mm, no contact, a 45° irradiation angle, and a 30-s exposure time using to-and-fro movements. The treatment consisted of two sessions with a 1-week interval. Pain severity was determined with the visual analog scale (VAS) at all the study intervals using a dry ice spray. The data were analyzed with SPSS version 20 using one-way ANOVA, repeated measures ANOVA, and least significant difference tests. Significance level was set at α = 0.05. Results: The changes in VAS were significant only in the first stage (P = 0.046). The mean VAS scores decreased over time in the 810-nm and 980 laser groups. A comparison of VAS changes relative to the baseline revealed significant changes in VAS scores at all the time intervals with both lasers. The two 810 and 980-nm laser groups did not exhibit any significant differences for 2 months postoperatively (P = 0.098). Conclusion: The application of 810 and 980-nm diode lasers at 1-W power and an exposure time of 30 s was effective in decreasing pain in patients with dentin hypersensitivity, with no significant difference between these two lasers.

Evaluation of Microleakage in Resin Composites Bonded to an Er:YAG Laser and Bur-Prepared Root and Coronal Dentin Using Different Bonding Agents.

Introduction: This study was conducted to assess the microleakage in Er:YAG laser-ablated and bur-prepared root and coronal dentin cavities using self-etch and total-etch adhesive systems. Methods: Sixty extracted caries-free human third molars were sectioned for dentin exposure. Then, two standard class V cavities were prepared in the root and coronal dentin of each tooth and allocated to one of the following conditioning groups randomly (n=12/Group): G1: Diamond bur for cavity preparation and single bond (BESB) etch-and-rinse adhesive for bonding, G2: Er:YAG laser (160 mJ, 20 Hz, 29.88 J/cm2) and SB (LESB), G3: Er:YAG laser and SB without acid etching (LSB), G4: Diamond bur and Clearfil SE Bond (BCSE) self-etch system, and G5: Er:YAG laser and Clearfil SE Bond (LCSE). The cavities were filled with Z100 composite resin. Dye penetration was assessed after thermocycling. Data analysis was done by Kruskal-Wallis and Mann-Whitney U tests. Statistical significance was set at P<0.05. Results: The results showed there were no statistically significant differences in microleakage between the two preparation methods (bur and laser) or the bonding agents applied (P>0.05). Regardless of the cavity preparation method, dye penetration was significantly higher in coronal dentin than in root dentin (P<0.05). Conclusion: The Er:YAG laser had the same efficacy as the conventional method for cavity preparation, and microleakage did not depend on the bonding agent. Microleakage was significantly higher in coronal restorations than in root restorations.

Evaluation of the Effects of 660-nm and 810-nm Low-Level Diode Lasers on the Treatment of Dentin Hypersensitivity.

Introduction: Dentin hypersensitivity is a common oral problem that occurs as a short and sharp pain. There are many techniques to treat this condition, the latest of which is laser treatment. The aim of this study was to evaluate the effect of two types of low-power diode lasers (660 nm and 810 nm) on dentin hypersensitivity in order to achieve an acceptable clinical application by adjusting the effective parameters. Methods: In this randomized, double-blind clinical trial, sensitive teeth of 7 patients were divided into three groups with a randomized matching method: group I, treated with 660-nm diode laser irradiation, group II, treated with diode laser 810-nm, and group III, the control group. Irradiation parameters for 660-nm and 810-nm diode lasers were the power of 30 mW and 100 mW respectively, in contact and continuous modes, perpendicular to the tooth surface with a sweeping motion. Treatments were carried out in four sessions at weekly intervals. The data obtained were analyzed with SPSS 22, using one-way repeated measures ANOVA and the LSD (least significant difference) test. The significance level was considered as P≤0.05. Results: There were no significant differences in visual analogue scale (VAS) score changes between the two laser groups after the intervention in the first, second and third weeks compared to the baseline (P>0.05). These changes in the fourth week were significantly higher in the 810-nm laser group compared to the 660-nm laser group (P=0.04), and in the 660-nm laser group, they were more than the control group (P=0.02). The mean VAS scores at 1-week, 1-month and 2-month postoperative intervals were significantly lower in the 810-nm laser group than in the 660-nm laser group, and in the 660-nm laser group, they were less than the control group (P<0.001). Conclusion: The use of 660-nm and 810-nm diode lasers with the power of 30 and 100 mW respectively for 120 seconds was effective in reducing pain in patients with dentin hypersensitivity. However, the effect of the 810-nm laser on reducing the dentin hypersensitivity was more long-lasting than that of the 660-nm laser.

Comparative Evaluation of the Effects of CO2 and Er:YAG Lasers on Smear Layer Removal and Blood Cell Attachment to Tooth Root Surfaces.

Introduction: The tooth root surfaces are modified by different agents for better removal of the smear layer, the formation of fibrin clots, and the attachment of blood cells. This in vitro study compared the removal of the smear layer, the formation of fibrin clots and the attachment of blood cells after exposing periodontally compromised root surfaces to ER:YAG and CO2 laser beams. Methods: Eighteen dentin block samples were prepared from freshly extracted periodontally compromised teeth that were deemed hopeless, and they were divided into 3 groups: exposed to Er:YAG laser beams, exposed to CO2 laser beams, and the control group. The samples were evaluated using scanning electron microscopy and micrographs were taken. Smear layer removal and blood cell attachment were scored. Data were analyzed using Kruskal-Wallis and MannWhitney tests. Results: In the Er:YAG laser group, the smear layer was removed completely. In the specimens exposed to blood, better fibrin clot formation and blood cell attachment were observed in the Er:YAG laser group. In the CO2 laser group, the smear layer was also removed; however, there were no significant differences between the CO2 laser and control groups in fibrin clot formation and blood cell attachment. Conclusion: The application of the Er:YAG laser to the root dentin appears to result in the formation of a suitable surface for fibrin clot formation and blood cell attachment. Further clinical studies are necessary to support these results.

Effectiveness of buccal pouch grafting in minimizing loss of alveolar dimension: A canine investigation.

BACKGROUND: The study's purpose was to study buccal pouch grafting (BPG) with xenograft, freeze-dried bone allograft (FDBA), or FDBA + decalcified FDBA (DFDBA) on alveolar ridge width preservation and overlying soft tissue thickness at dog premolar extraction sites. MATERIALS AND METHODS: In this animal study, 4 dogs had their mandibular first premolar (P1) and distal roots of P2, P3, and P4 extracted (after endodontic treatment of the mesial roots) bilaterally. A small buccal pouch was created at each extraction socket and four treatments tested: nothing, xenograft, FDBA, or FDBA + DFDBA. Casts made pretreatment and at 1 and 3 months after treatment allowed measurements of buccolingual alveolar ridge width (BLRW), while overlying buccal soft tissue thicknesses were measured clinically. Data were assessed using analysis of variance to compare changes in soft tissue thickness and BLRW between times and treatments. Tukey-Kramer adjustment for multiple comparisons was applied for doing post hoc, pairwise comparisons. Results were considered significant if P < 0.05. RESULTS: Control sites showed significant (P = 0.0067) decreases in soft tissue thickness over time while there was a trend for increased soft tissue thickness at all grafted sites. There were significant losses in BLRW over time for control (P = 0.0032) and FDBA groups (P = 0.015) with a trend for loss with FDBA + DFDBA. Pairwise comparison using Tukey-Kramer adjustment revealed significant increases in BLRW from T1 to T3 for the xenograft group relative to all the others. CONCLUSION: BPG using xenograft is effective in maintaining hard and soft tissue stability following tooth extraction.

Retro MTA and tricalcium phosphate/retro MTA for guided tissue regeneration of periodontal dehiscence defects in a dog model: a pilot study.

OBJECTIVES: Retro MTA is a fast setting Calcium silicate cement used in endodontic regeneration procedures in recent years. Beta-tricalcium phosphate (ß-TCP) is another common biomaterial used for bone augmentation procedures. The present pilot study was undertaken to evaluate and compare the efficacy of Retro MTA and a mixture of Retro MTA / ß-TCP for periodontal tissue regeneration. MATERIALS AND METHODS: In 4 beagle dogs, periodontal dehiscence type defects were created. In each side, one dehiscence defect was left empty as a control site and three treatment modalities were randomly applied for the others: Retro MTA covered with a collagen membrane, Retro MTA + ß-TCP covered with a membrane and covering the defect with a membrane without any bone augmentation. After 8 weeks Animals were sacrificed and Histomorphometric and histologic analysis were conducted. RESULTS: Histologic analysis showed more cementum formation for both Retro MTA+ ß-TCP (3.74 ± 0.34 mm) and Retro MTA group (3.24 ± 0.56 mm) compared to control group 1 (1. 15 ± 0.45 mm) and control group 2 (0.78 ± 0.65 mm). Formation of newly formed bone and cementum in the experimental groups were significantly higher as compared to the control groups (P < 0.0001). CONCLUSIONS: Retro MTA or Retro MTA+ ß-TCP covered with a collagen membrane resulted in regeneration of periodontal tissues. However, Retro MTA+ ß-TCP showed tendency towards better results than the use of Retro MTA alone.

Investigation of the antibacterial effect of laser irradiation and chemical agent on human oral biofilms contaminated titanium discs.

INTRODUCTION: A main challenge in treatment of peri-implant disease is the effective decontamination of the implant surface. This challenge has always been a problem, associated with the treatment of these diseases with regard to the difficulty in removing and eliminating bacterial biofilm from the surface of dental implants, especially rough surfaces. The aim of this in-vivo study was to evaluate the effect of five different antimicrobial methods in reducing bacteria adhering to titanium surfaces. MATERIALS AND METHODS: In the present in-vivo study, the contaminated discs, except for the negative control group, randomly underwent one of five treatments: Erbium: Yattrium Aluminum Garnet (Er-YAG) laser, plastic curette, 0.12% chlorhexidine, aPDT, and 810 nm diode laser. A pectrophotometer was used to measure Optical Density (OD) in case of aerobic microorganisms. Colony-Forming Units (CFUs) were used for anaerobic bacteria. Then, all the analyses were carried out at a significance level of α = 0.05 through SPSS software. FINDINGS: One-way analysis of variance (ANOVA) of aerobic bacteria showed a significant difference among 6 groups in terms of OD variations during a 0-24 h time interval (P < 0.001). The results of Kruskal-Wallis test were used to investigate the effect of study methods on anaerobic bacteria after 48 h, and the results showed a significant difference among 6 groups in terms of CFUs (P < 0.001). CONCLUSION: The results of the present study showed that all five mechanicals (plastic curette), chemical (CHX), laser (810 nm diode and Er: YAG), and aPDT methods could reduce oral biofilms from roughed surfaces of titanium discs. Er: YAG laser and plastic curette had the highest and the lowest effects respectively.

Thermal Changes of Root Surface of Anterior Primary Teeth in Pulpectomy with Er:YAG Laser.

OBJECTIVES: Successful root treatment depends on elimination of microorganisms from the root canal. Considering incomplete removal of bacteria from the canal by usual methods, lasers have been suggested as a new modality. Despite their anti-bacterial properties, lasers can cause thermal changes. This study assessed the thermal changes of root surface in pulpectomy of primary teeth following the use of Er:YAG laser. MATERIALS AND METHODS: Sixty primary anterior teeth were collected and prepared by K-file up to number 50. Then, they were randomly divided into two groups and were irradiated with Er:YAG laser. The first group was irradiated with 1 W laser and the second group with 1.5 W laser. The laser irradiation time was two 10-second cycles with a 2-second interval in both groups. Thermal changes were measured by a thermometer in the apical and coronal areas per second. The results were analyzed by repeated measures ANOVA considering the laser power as between-subject variable. RESULTS: There was a temperature increase in the coronal and apical areas in use of 1 W power. There was a temperature rise in the coronal and apical areas in use of 1.5 W power. The temperature rise in the apical third was more than that in the coronal third; also, the average temperature rise was more in use of 1.5 W power than 1 W power. CONCLUSIONS: As the average temperature increase was not more than 7°C in any group, this type of laser seems to be suitable for root treatment of primary anterior teeth.

Evaluation of Effectiveness of Photodynamic Therapy With Low-level Diode Laser in Nonsurgical Treatment of Peri-implantitis.

Introduction: Side effects related to antibiotic therapy for peri-implantitis are rare in laser therapy (LT); therefore, the aim of this study was to evaluate the effectiveness of LT and photodynamic therapy (PDT) on patients with primary peri-implantitis. Methods: In this randomized clinical trial, 40 implants presenting primary peri-implantitis in 20 patients with a mean age of 52.6 years old were included using the simple sampling technique. Periodontal treatment comprising scaling and root planing (SRP) was accomplished for the whole mouth while mechanical debridement with titanium curettes and air polishing with sodium bicarbonate powder was accomplished around the implants. The implants were randomly divided into two groups and treated with LT (control) and PDT (test). The clinical indices were measured at baseline, 6 weeks and 3 months after treatment. Real-time polymerase chain reaction (PCR) was used for analysis of microbial samples at baseline and 3-month follow-up. Data were analyzed with SPSS 20, using repeated-measures analysis of variance (ANOVA) and Friedman's and Mann-Whitney tests (α = 0.05). Results: Both groups showed statistically significant improvements in terms of bleeding on probing (P < 0.001), probing pocket depth (PPD) (P = 0.006) and modified plaque index (P < 0.001), with no significant differences between the 2 groups (P > 0.05). The number of Aggregatibacter actinomycetemcomitans (P = 0.022), Tannerella forsythia (P = 0.038) and Porphyromonas gingivalis (P = 0.05) in the test group and Porphyromonas gingivalis (P = 0.015) in the control group significantly decreased. Conclusion: The results suggested that LT and PDT have significant short-term benefits in the treatment of primary peri-implantitis.

The Effect of Er:YAG Laser on Entroccocus faecalis Bacterium in the Pulpectomy of Anterior Primary Teeth.

Introduction: Successful root canal therapy depends on the complete elimination of microorganisms such as Entroccocus faecalis, which is impossible to achieve with the traditional methods. Lasers are recently introduced as a new method to solve the problem. The present study is planned and performed to examining the antibacterial effect of Er: YAG laser. Methods: Sixty extracted anterior primary teeth were prepared and sterilized. E. faecalis bacterium was cultured in canals. Samples were randomly divided into two groups. The first group was disinfected by NaOCl 5/25% and Er: YAG laser and the second group just by NaOCl 5/25%. Samples of canal contents were cultured and colony counts were calculated. The results were analyzed statistically by SPSS software and Mann Whitney test. Results: There was no significant difference between colony counts in both groups (P=0.142). But the number of colonies in the first group was lower than in the second group. Conclusion: Although, Er: YAG laser cannot completely eliminate E. faecalis bacterium, its simultaneous use with NaOCl decreases E. faecalis.

Comparison of Er:YAG Laser and Ultrasonic Scaler in the Treatment of Moderate Chronic Periodontitis: A Randomized Clinical Trial.

Introduction: Periodontitis is an inflammatory periodontal disease that leads to tooth loss. Recently laser has been introduced as an alternative treatment for periodontitis. The aim of the present study was to compare the effect of Erbium-doped Yttrium Aluminum Garnet (Er:YAG) laser with ultrasonic scaler in patients with moderate chronic periodontitis. Methods: In this randomized single-blind clinical trial, 27 patients with moderate chronic periodontitis were selected. One quadrant of the patients was treated by Er:YAG laser and the other one by ultrasonic scaler. Clinical parameters, including periodontal pocket depth (PPD), papillary bleeding index (PBI) and clinical attachment level (CAL) were measured before, as well as 6 and 12 weeks after treatment. Data were analyzed by SPSS 20 software using Friedman test, paired t test, independent t test and Mann-Whitney test. The significance level was set at 0.05. Results: The means of clinical parameters in both groups were significantly improved in the first and second follow-ups (P < 0.001). Although the means of PPD, PBI and CAL were slightly higher in the laser group than in the ultrasonic group, the differences were not statistically significant between these two groups (P > 0.05). Conclusion: Although both ultrasonic scaler and Er:YAG laser could effectively improve clinical periodontal parameters, the results did not reveal the superiority of Er:YAG laser over ultrasonic scaler or vice versa.

Histological Evaluation of Wound Healing Process after Photodynamic Therapy of Rat Oral Mucosal Ulcer.

STATEMENT OF THE PROBLEM: When the body defense is compromised, wounds can act as a route for entrance and colonization of microorganisms in the body. Photodynamic therapy with methylene blue is known as a promising antimicrobial modality. PURPOSE: The present study aimed to investigate the effects of this procedure on wound healing processes. MATERIALS AND METHOD: In this experimental study, 48 male Wistar rats were recruited. Experimental wounds were surgically made on their buccal mucosa. Based on the treatment modality, they were divided into 3 groups (n=16) of control (CG), laser (LG), photosensitizer+ laser (PLG) by methylene blue (MB). The treatment procedure in the two latter groups was done in days 1-4 and 6-9. After sacrificing on 2, 4, 7 and 14-day follow-ups, the microscopic grade of healing of the wounds was assigned on each interval according to histological grading criteria. RESULTS: A qualitative result was obtained that showed a healing progression in PLG at day 2 of follow-up. At day 4 of follow-up, no difference was seen in healing stage among the groups. However on day 7 of follow-up, samples of the LG showed a lower degree of healing compared with the other two groups. Likewise, on day 14 of follow- up, both PLG and LG showed lower degree of healing than CG. CONCLUSION: This study qualitatively showed that MB- mediated photodynamic therapy would have an inhibitory effect on healing process after 14 days of the wound creation.

Evaluation of the effects of two different bone resorption inhibitors on osteoclast numbers and activity: An animal study.

BACKGROUND: The aim of this study was to evaluate the effects of bone resorption inhibitors, doxycycline (DOX) and erythromycin (EM), on osseous wound healing in rat alveolar socket. MATERIALS AND METHODS: In this randomized controlled trial, 45 8-10-week-old male Wistar rats had their maxillary right molar extracted. They were divided into three groups of 15. In Group 1 normal saline, Group 2 DOX, and Group 3 EM were administered at the doses of 5 ml/kg/day, 5 mg/kg/day, and 2 mg/kg/day, respectively, for 7 consecutive days. The rats were sacrificed 7, 14, and 21 days after surgery. Real-time polymerase chain reaction was employed to evaluate the mRNA expression of receptor activator of nuclear factor κB ligand (RANKL) and osteoprotegerin (OPG) and immunohistochemical staining for tartrate-resistant acid phosphatase (TRAP) to determine osteoclasts. The data were analyzed by one-way analysis of variance followed by Tukey's post hoc test using SPSS version 20. Significant level was set at 0.05. RESULTS: The results showed that when drug-treated groups compared to control groups, RANKL gene expression significantly decreased, TRAP+ cells decreased on day 7. The RANKL/OPG ratios in the first two weeks in the test groups were significantly lower than the control group. There was no significant difference in the studied indices between DOX and EM groups. CONCLUSION: Following administration of DOX and EM, the number of osteoclasts and RANKL/OPG ratio decreased suggesting their anti-osteoclastogenesis activity. These two drugs have no advantage over each other in increasing the bone formation.

Effect of Nonsurgical Periodontal Treatment Combined With Diode Laser or Photodynamic Therapy on Chronic Periodontitis: A Randomized Controlled Split-Mouth Clinical Trial.

INTRODUCTION: The optimum removal of bacteria and their toxins from periodontal pockets is not always obtained by conventional mechanical debridement. Adjunctive therapies may improve tissue healing through detoxification and bactericidal effects. The purpose of the present study was to evaluate the impact of adjunctive laser therapy (LT) and photodynamic therapy (PDT) on patients with chronic periodontitis. METHODS: Twenty patients with at least three quadrants involved and each of them presenting pockets 4-8 mm deep were included in the study. Periodontal treatment comprising scaling and root planning (SRP) was accomplished for the whole mouth. Applying a split-mouth design, each quadrant was randomly treated with SRP alone (group A), SRP with LT (group B), and SRP with PDT (group C). The clinical indices were measured at baseline 6 weeks and 3 months after treatment. Microbiological samples were taken and evaluated at baseline and 3-month follow-up. RESULTS: All groups showed statistically significant improvements in terms of clinical attachment level (CAL) gain, periodontal pocket depth (PPD) reduction, papilla bleeding index and microbial count compared to baseline (P < .05). The results showed more significant improvement in the 6-week evaluation in terms of CAL in groups B and C than in group A (P < .05). Group B also revealed a greater reduction in PPD than the other treatment modalities (P < .05). CONCLUSION: The obtained data suggested that adjunctive LT and PDT have significant short-term benefits in the treatment of chronic periodontitis. Furthermore, LT showed minimal additional advantages compared to PDT.

A histomorphometric study of the effect of doxycycline and erythromycin on bone formation in dental alveolar socket of rat.

BACKGROUND: The aim of the present study was to evaluate whether subantimicrobial doses of doxycycline (DOX) and erythromycin (EM) used for the treatment of peri-implant osteolysis due to their anti-osteoclastogenesis can interfere with the osseous wound healing process in rat alveolar socket. MATERIALS AND METHODS: Forty-five male Wistar rats had their first maxillary right molar extracted and were divided into three groups. DOX and EM at the doses of 5 mg/kg/day orally (p.o.) and 2 mg/kg/day intraperitoneally (i.p.) were administered respectively to two separate groups for 7 days after operation. In the control group the animals received normal saline (5 ml/kg). Five rats were sacrificed at 7, 14 and 21 days post-extraction in each study group. A histomorphometric analysis was used to evaluate new bone formation inside the alveolar socket. Significant level was set at 0.05. RESULTS: The findings showed that the percentage of new bone formation (NBF) enhanced significantly on days 7 and 14. There was no significant difference in the NBF between DOX and EM groups. CONCLUSION: Short-term treatment with both DOX and EM enhanced new bone formation without any advances in favor of each drug.

Effect of Nd:YAG Laser Irradiation on the Number of Open Dentinal Tubules and Their Diameter with and without Smear of Graphite: An in Vitro Study.

INTRODUCTION: Dentin hypersensitivity (DH) is characterized by tooth pain arising from exposure of dental roots. In this study the efficiency of neodymium yttrium-aluminum-garnet (Nd:YAG) laser in association with graphite on dentinal surface changes as the alternative to the treatment of DH was evaluated. METHODS: Sixteen noncarious human third molars were collected and sectioned into 5 parts from cementoenamel junction (CEJ) to the furcation area. The prepared samples were randomly assigned into five groups (Gs) of each 16: Control (G1), treated by Nd:YAG laser at 0.5 W (G2), irradiation of Nd:YAG with a 0.25 W output power(G3), smeared with graphite and then using Nd:YAG laser at output powers of 0.5 W (G4) and 0.25 W (G5). For all groups the parameters were 15 Hz, 60 s, at two stages and with a right angle irradiation. The number and diameter of dentinal tubules (DT) were compared and analyzed by SPSS software, One way ANOVA and Post hoc LSD tests. RESULTS: The number of open dentinal tubules varied significantly between all groups except among G1 with G3 and G2 with G5. Multiple comparison tests also exhibited significant differences regarding the diameter of tubules between the groups two by two except among G2 with G5. CONCLUSION: Nd:YAG laser used at 0.25 W and 0.5 W with application of graphite smear was able to reduce the number and diameter of dentinal tubules.