Relationship of Maxillary Sinus Mucosal Thickening and Residual Alveolar Ridge Height: A CBCT Analysis.

Objectives: Maxillary sinus pathological conditions, like thickening of the Schneiderian membrane, can influence the outcomes of augmentation procedures and implant treatment. The present study aimed to evaluate the relationship between the residual ridge height and maxillary sinus membrane thickening. Materials and Methods: A total of 240 cone-beam computed tomography (CBCT) images of the maxillary sinus of 141 patients (62.1% males and 37.9% females, bilateral in 99 patients and unilateral in 42 patients) who were candidates for implant placement were evaluated. The CBCT scans were subsequently assessed for the following variables: residual ridge height, sinus membrane thickening at future implant(s) site(s), the ostium patency, and presence of periapical lesion adjacent to the edentulous area. Results: The total prevalence of sinus membrane thickening (66.2%) was sub-classified as follows: flat in 53.7%, polypoid in 12.1%, and complete opacification in 0.4%. The prevalence of sinus membrane thickening was higher in male participants. It was revealed that age had no significant relationship with presence of a periapical lesion or sinus membrane thickening (P>0.05). Membrane thickening was detected in all sinuses with obstructed ostium. Reduced residual ridge height was significantly associated with higher sinus membrane thickening at the second premolar and first molar sites (P<0.05). Conclusion: Maxillary sinus membrane thickening (mostly with flat appearance) is frequently observed on CBCT scans taken prior to augmentation and implant placement. This, in return, may trigger a reduction in ridge height.

Efficacy of Adjunctive Antimicrobial Photodynamic Therapy to Mechanical Debridement in the Treatment of Peri-implantitis or Peri-implant Mucositis in Smokers: A Systematic Review and Meta-analysis.

This systematic review and meta-analysis aimed to determine whether adjunctive use of antimicrobial photodynamic therapy (a-PDT) in peri-implant diseases improves clinical outcomes in smokers. An electronic search was performed in MEDLINE (through PubMed), Scopus, Cochrane Library, Embase, Web of Science and Google Scholar. The primary outcome measures were bleeding on probing (BOP) and pocket depth (PD). Plaque index (PI) was the secondary outcome. Four RCTs, (188 participants) comprised of 118 cigarette smokers, 38 E-cig smokers and 32 water pipe smokers with follow-up periods ranged from 6 weeks to 6 months were recruited. All trials applied diode laser in one session with wavelengths ranged from 660 to 670 nm. There was a significant difference between mechanical debridement (MD)+a-PDT and MD alone groups in PD (WMD = -1.26 mm, 95% CI: -2.19 to -0.32, P = 0.01) and PI (WMD = -10.60%, 95% CI: -14.46 to -6.74, P < 0.001) at 3-month follow-up. However, a great amount of heterogeneity was observed (PD: χ2 = 199.19, I2 = 98%, P < 0.001 and PI: χ2 = 25.63, I2 = 84.4%, P < 0.001). Due to methodological heterogeneity and small number of studies, this systematic review was unable to reach conclusive evidence in regards of adjunctive a-PDT efficacy in improving clinical parameters in smokers.

Semelil as Adjunctive Therapy in Chronic Periodontitis: A Preliminary Randomized Controlled Clinical Study.

Host modulation therapy is recently employed to improve periodontal treatments outcome. This randomized controlled clinical trial aimed to evaluate the effects of Semelil (ANGIPARS) as an adjunct to non-surgical treatment in patients with chronic periodontitis. Forty-four healthy subjects with moderate to severe chronic periodontitis were enrolled in the study. After completion of phase I periodontal therapy, including oral hygiene instruction, scaling, and root planing, the patients were randomly divided into two groups to receive capsules of Semelil (test) or placebo (control), consuming two capsules a day for three months. Clinical parameters (probing depth [PD], clinical attachment level [CAL], modified sulcular bleeding index [MSBI], modified gingival index [MGI], and plaque index [PI]) and biochemical parameters (interleukin-1ß [IL-1ß], 8-hydroxy-2-deoxyguanosine [8-OHdG]), and lipid peroxidation [LPO]) were measured at baseline and after completion of treatment. Twenty-five patients completed the study: 15 in the test group and 10 in the control group. All clinical and biochemical parameters were significantly improved from baseline to the final measurements in both groups (p < 0.001). The changes were more pronounced in the test group in comparison to the control group. However, the differences between the groups were significant only for MGI, MSBI, PD, and CAL (p < 0.05). Semelil may reveal promising results as an adjunctive treatment for chronic periodontitis.

Assessment of preload, remaining torque, and removal torque in abutment screws under different frictional conditions: A finite element analysis.

STATEMENT OF PROBLEM: Contamination with salivary fluids or blood during the treatment process changes the preload, remaining torque, and removal torque of retained screws, which ultimately affects the resistance to screw loosening. In previous studies, no consensus has been reached as to whether contamination can be used as a lubricant. PURPOSE: The purpose of this 3-dimensional (3D) finite element analysis study was to compare the preload, remaining torque, and removal torque under different frictional conditions in the processes of tightening, waiting period, and removal of abutment screws using a numeric method and finite element analysis. MATERIAL AND METHODS: Three-dimensional finite element models of a single implant restoration including a crown, dental implant, abutment, and abutment screw, along with the surrounding bone, were constructed. The geometry of all threaded interfaces was designed as a threaded helix. The Abaqus software was used to perform the dynamic simulation of 3 steps such as tightening, waiting period, and removal. Three static and kinetic friction conditions were considered to determine the effect of different frictional conditions. The values of preload at the tightening step, remaining torque at the waiting period, and removal torque at the removal step were evaluated and compared with theoretically predicted values. RESULTS: The amount of removal torque required to loosen the abutment screw was smaller than the insertion torque for all frictional conditions. By decreasing the coefficient of friction, the remaining torque and the preload increased, and the torsional relaxation and removal torque decreased. CONCLUSIONS: Although the value of the removal torque decreased by decreasing the coefficient of friction, the resistance to screw loosening increased with the increase of the preload and the increase of the remaining torque in the implant complex assembly. Considering the biological complications of fluid lubricants, clinicians may contaminate the abutment screw with lubricants. Gold-coated screws should also be preferred to noncoated screws.

Photodynamic Inactivation of Porphyromonas gingivalis utilizing Radachlorin and Toluidine Blue O as Photosensitizers: An In Vitro Study.

Introduction:Porphyromonas gingivalis is one of the major pathogens in the development and progression of periodontal disease. Antimicrobial photodynamic therapy (aPDT) is a new approach which is sorted in non-invasive phototherapy for bacterial elimination. This in vitro study was conducted to compare photodynamic inactivation using Radachlorin and Toluidine blue O (TBO) as photosensitizers on P. gingivalis. Methods: Bacterial suspensions (200 µL) of P. gingivalis were exposed to either TBO with concentration of 0.1 mg/mL associated with portable light-emitting diode (LED) device (peak wavelength: 630 nm, output intensity: 2.000 mW/cm2, tip diameter: 6.2 mm) or 0.1% Radachlorin® and laser irradiation (InGaAlP, Peak wavelength: 662±0.1% nm, output power: 2.5 W, energy density: 6 J/cm2, fiber diameter: 2 mm). Those in control groups were subjected to laser irradiation or LED alone, Radachlorin® or TBO alone, and one group received neither photosensitizer nor light irradiation. Then counting of colony forming units (CFU) was performed to determine the bactericidal effects in each subgroup. Results: LED-based aPDT reduced the colony count of P. gingivalis more than that of TBO (P<0.001) or LED group (P=0.957). Also, laser-based aPDT had a great reduction in colony count of P. gingivalis in comparison with Radachlorin® (P<0.001) or laser irradiation alone (P=0.28). In addition, the colony count reduction of laser-based aPDT was significantly more than LED-based aPDT (P<0.05). Conclusion: Considering the results of this study, the viability of P. gingivalis was more affected by the combination of laser and Radachlorin® 0.1% in comparison with LED and TBO 0.1.

Lactobacillus salivarius NK02: a Potent Probiotic for Clinical Application in Mouthwash.

A specific strain of naturally occurring oral lactobacilli was isolated and identified based on morphological, biochemical, and 16S rRNA gene sequencing. The phylogenetic affiliation of the isolate confirmed that the NK02 strain had close association with the Lactobacillus salivarius. An effective mouthwash was developed for treatment of periodontitis and suppression of the indicator bacterium Aggregatibacter actinomycetemcomitans which is an obvious pathogen of periodontal disease. The mouthwash containing L. salivarius NK02 was tested at a dose level of 108 (colony forming units (CFU) ml-1), monitoring over a period of 4 weeks. The study was a randomized double-blind placebo control trial, and the patients were treated in two groups of control and test by using scaling and root planing (SRP) + placebo and scaling and root planing (SRP) + probiotic, respectively. It appeared that the probiotic mouthwash was able to inhibit the bacterial growth on both saliva and sub-gingival crevice and exhibited antibacterial activity against A. actinomycetemcomitans. The results also showed that SRP+ probiotic treatment led to a significant decrease of gingival index (GI) and bleeding on probing (BOP) compared with that of SRP + placebo for the probiotic group. The rate of decrease in pocket depth was displayed in the group with SRP + probiotic treatment equal to 1/2 mm, and probing pocket depth (PPD) value was decreased in the probiotic bacteria treatment group that can explain the decrease in inflammation in gingiva. Our findings suggest that probiotic mouthwash is healthy for daily use as an alternative for maintaining dental and periodontal health.

Effect of laser photobiomodulation on wound healing and postoperative pain following free gingival graft: A split-mouth triple-blind randomized controlled clinical trial.

BACKGROUND AND AIM: Free gingival graft (FGG) is one of the most predictable techniques for gingival augmentation. However, patient's discomfort and pain during healing period are significant concerns. The aim of this study was to assess if laser photobiomodulation (PBM) was effective in terms of enhancing wound healing and reducing postoperative pain. METHODS AND MATERIALS: Twelve patients participated in this split-mouth randomized controlled clinical trial. Each patient had a 30-day interval between the two procedures. In the test group, donor and recipient sites received diode laser (660nm, 200mW, continuous mode, time of irradiation:32s, energy density: 4J/cm2, spot size:0.5cm) immediately after FGG surgery, and 1,2,4 and 7days later. The control side received the same sequence of irradiation with the laser-off. Complete wound epithelialization of donor site and clinical wound healing and visual analogue scale (VAS) pain score of donor and recipient sites were evaluated after surgery. RESULTS: At 14 and 21days after surgery, the number of donor sites with complete epithelialization was greater in laser group compared to the placebo. After 21days, all donor sites in the test group were epithelialized completely, while at the same time, only eight donor sites in the control group showed complete epithelialization (P value=0.05). In terms of clinical healing of the recipient and donor sites, the test and control groups did not show any significant difference during the 45-day period, except at days 1 (for recipient site) and 14 (for donor site), when the test group showed better results (P values: 0.01 and 0.03, respectively). The VAS pain score did not show statistically significant difference between two groups during the study period, except for the first 3h after procedure when laser group showed greater VAS pain score (P values<0.05). CONCLUSION: PBM following FGG procedure with the parameters used in this study could accelerate the rate of epithelialization at the donor site. However, it did not reduce postoperative pain.

Intra- and Postoperative Complications of Lateral Maxillary Sinus Augmentation in Smokers vs Nonsmokers: A Systematic Review and Meta-Analysis.

PURPOSE: This meta-analysis and systematic review focused on the following question: Does tobacco smoking increase the risk of intra- or postoperative complications of lateral maxillary sinus floor elevation? MATERIALS AND METHODS: The following electronic databases were searched up to and including November 2015 without language restriction: CENTRAL, MEDLINE, Google Scholar, Scopus, Sirous, and Doaj. Studies were included if rates of intra-or postoperative complications of sinus floor elevation in smokers and nonsmokers were recorded separately. The following complications were assessed: sinus membrane perforation, bleeding, wound dehiscence, wound infection, sinusitis, hematoma, and oroantral fistula. The Critical Appraisal Skills Programme was used to assess the risk of bias in included studies. Random-effects meta-analyses were used to assess the number of each complication in smokers and nonsmokers. RESULTS: Out of 929 eligible publications, 11 articles were included. Meta-analysis of the studies revealed a significantly increased risk of developing wound dehiscence after sinus floor elevation among smokers compared with nonsmokers (Risk Ratio [RR]: 7.82; 95% confidence interval [CI]: 2.38, 25.74; P = .0007). Moreover, risk of developing wound infection was greater in smokers when prospective studies were included in the meta-analysis (RR: 5.33; 95% CI: 1.34, 21.25; P = .02). However, the meta-analysis of included studies did not show significant differences between smokers and nonsmokers concerning risk of sinus membrane perforation and bleeding during sinus floor elevation (P = .46 and P = .33, respectively). CONCLUSION: Considering the lack of randomized controlled trials and the small number of included studies, the results indicate that smoking seems to be associated with increased risk of wound dehiscence and infection after the sinus augmentation procedure.

Effect of Flapless Immediate Implantation and Filling the Buccal Gap with Xenograft Material on the Buccal Bone Level: A Randomized Clinical Trial.

OBJECTIVES: Following tooth extraction, soft and hard tissue alterations occur; Different factors can affect this process. The objective of this study was to determine the effect of gap filling on buccal alveolar crestal bone level after immediate implant placement after 4- to 6-month observation period. MATERIALS AND METHODS: This randomized clinical trial was performed on 20 patients (mean age of 38.8 years) requiring tooth extraction in a total of 27 areas in the anterior maxilla. The treatment strategy was as follows: atraumatic flapless tooth extraction, implant placement, insertion of a graft (test group) or no material (control group) between the implant and the socket wall, connection healing abutment placement and suturing the area. Clinical and cone beam computed tomographic examinations were performed before implant placement (baseline), 24 hours after surgery and 4-6 months (T2) after implant placement, to assess the buccal plate height (BH) and implant complications. RESULTS: After 4 months of healing, a reduction in different bone measurements was noticed in the two groups. No statistically significant differences were assessed in bone height measurements between the test and control groups at different time points. The study demonstrated that immediate implantation resulted in 1.30 and 1.66 mm reduction in buccal bone plate in the test and control groups, respectively. CONCLUSIONS: The study demonstrated that immediate implantation in the extraction socket together with xenograft failed to prevent bone resorption.

Effect of Periodontal Treatment on the Crevicular Level of High-mobility Group Box 1 and Soluble Triggering Receptor Expressed on Myeloid Cells 1 in Patients with Chronic Periodontitis.

The present study aimed to compare the levels of high-mobility group box 1(HMGB1) and soluble triggering receptor expressed on myeloid cells (sTREM1) in the gingival crevicular fluid (GCF). This cross-sectional cohort trial investigated two groups of 22 eligible chronic periodontitis and 22 periodontally healthy individuals (student volunteers) both before and after the periodontal treatment.  GCF was collected from the deepest pockets with clinical attachment loss≥3 mm. Both groups received oral hygiene instructions, and scaling and root planning were performed in the test group. Enzyme-linked immunosorbent assay kit (ELISA) was used to measure the levels of HMGB1 and sTREM1 in GCF samples collected before and 1 month after non-surgical periodontal treatment. The results showed that HMGB1 levels were significantly higher in the chronic periodontitis patients than those of the healthy individuals before treatment (p<0.02) and decreased significantly after periodontal treatment, which reduced gingival inflammation. Furthermore, the levels of sTREM1 marker were significantly higher in periodontitis patients before (p<0.001) and 1 month after treatment than in healthy individuals (p<0.003) although its crevicular levels decreased after periodontal therapy in periodontitis group. The higher levels of sTREM1 and HMGB1 cytokines in GCF of periodontitis patients and the significant decrease after the introduction of the periodontal treatment underlines the importance of HMGB1 and sTREM1 in pathogenesis of periodontitis.

Relationships between High-mobility Group Protein B1 and Triggering Receptor Expressed on Myeloid Cells Concentrations in Gingival Crevicular Fluid and Chronic Periodontitis.

One of the inflammatory mediators which is secreted by inflammatory cells is high-mobility group protein B1 (HMGB1). Interaction of HMGB1 and toll-like receptors (TLRs) leads to increased production of inflammatory cytokines. On the other hand, it was shown that triggering receptor expressed on myeloid cells (TREM-1) also can be activated by TLRs, and its soluble form (sTREM-1) can be formed by cleaving of membrane-bound form of TREM-1 proteinases. Since there is not enough knowledge about the precise role of HMGB1 and sTREM-1 in periodontal diseases, the aim of this study was to evaluate the concentration of HMGB1 and sTREM-1 in gingival crevicular fluid (GCF) samples of patients with chronic periodontitis. Gingival crevicular fluid (GCF) samples were obtained from a total of 24 individuals with clinically healthy gingiva and 24 patients with moderate to severe chronic periodontitis. For collecting GCF samples, periopapers were placed at the entrance of the crevice and left in position for 30 seconds. Then, they were stored at -80°C. Enzyme-linked immunosorbent assay (ELISA) was used for measuring the concentration of HMGB1 and sTREM-1 in GCF samples. The concentration of HMGB1 (p<0.001) and sTREM-1 (p<0.017), was significantly higher in chronic periodontitis group. In addition, there was a significant positive correlation between HMGB1 and sTREM-1 concentration in chronic periodontitis group (p<0.05). We also found significant positive correlation between PD (Pocket depth) and the concentration of HMGB1 (p<0.001) and sTREM-1 (p<0.015). It is concluded that both HMGB1 and sTREM-1 are released during the inflammatory response of periodontal tissues and they can promote inflammatory process, which leads to tissue destruction.

An In Vitro Comparison of Antimicrobial Effects of Curcumin-Based Photodynamic Therapy and Chlorhexidine, on Aggregatibacter actinomycetemcomitans.

INTRODUCTION: Considering the importance of prevention in periodontal diseases and the important role of Aggregatibacter actinomycetemcomitans in induction and progression of these diseases, the aim of the present in vitro study was to compare the antimicrobial effects of chlorhexidine digluconate (CHX), curcumin and light-emitting diode (LED) laser, on this bacterium. METHODS: Antimicrobial activity of curcumin (5 mg/ml), CHX (2%), LED (120 J/cm(2)) and LED + curcumin (120 J/cm(2) + 2.5 mg/ml) against A. actinomycetemcomitans were tested in vitro, using micro-broth dilution test. One-way analysis of variance (ANOVA) and Tukey's HSD tests served for statistical analysis. RESULTS: Regarding the minimum inhibitory concentration (MIC), CHX had a significantly lower MIC than curcumin (P < 0.05). Sorted out by bacterial growth from lowest to highest, were CHX, LED + curcumin, curcumin, and LED groups. All the differences were found to be statistically significant (P < 0.05) except for the LED group. CONCLUSION: We conclude that curcumin is an effective substance in preventing the growth of A. actinomycetemcomitans, whose impact is reinforced when used simultaneously with photodynamic therapy (PDT).

Histologic evaluation of bone healing capacity following application of inorganic bovine bone and a new allograft material in rabbit calvaria.

OBJECTIVES: Considering the importance of bone augmentation prior to implant placement in order to obtain adequate bone quality and quantity, many studies have been conducted to evaluate different techniques and materials regarding new bone formation. In this study, we investigated the bone healing capacity of two different materials deproteinized bovine bone mineral (DBBM with the trade name of Bio-Oss) and demineralized freeze-dried bone allograft (DFDBA with the trade name of DynaGraft). MATERIALS AND METHODS: This randomized blinded prospective study was conducted on twelve New Zealand white rabbits. Three cranial defects with an equal diameter were created on their calvarium. Subsequently, they were distributed into three groups: 1. The control group without any treatment; 2. The Bio-Oss group; 3. The DynaGraft group. After 30 days, the animals were sacrificed for histologic and histomorphometric analysis. RESULTS: Substantial new bone formation was observed in both groups. DynaGraft: 56/1 % ± 15/1 and Bio-Oss: 53/55 % ± 13/5 compared to the control group: 28/6 % ± 11/2. All groups showed slight inflammation and a small amount of residual biomaterial was observed. CONCLUSION: Considerable new bone formation was demonstrated in both DynaGraft and Bio-Oss groups in comparison with the control group. Both materials are considered biocompatible regarding the negligible foreign body reaction.

Effect of the coefficient of friction and tightening speed on the preload induced at the dental implant complex with the finite element method.

STATEMENT OF PROBLEM: To prevent screw loosening, a clear understanding of the factors influencing secure preload is necessary. PURPOSE: The purpose of this study was to investigate the effect of coefficient of friction and tightening speed on screw tightening based on energy distribution method with exact geometric modeling and finite element analysis. MATERIAL AND METHODS: To simulate the proper boundary conditions of the screw tightening process, the supporting bone of an implant was considered. The exact geometry of the implant complex, including the Straumann dental implant, direct crown attachment, and abutment screw were modeled with Solidworks software. Abutment screw/implant and implant/bone interfaces were designed as spiral thread helixes. The screw-tightening process was simulated with Abaqus software, and to achieve the target torque, an angular displacement was applied to the abutment screw head at different coefficients of friction and tightening speeds. The values of torque, preload, energy distribution, elastic energy, and efficiency were obtained at the target torque of 35 Ncm. Additionally, the torque distribution ratio and preload simulated values were compared to theoretically predicted values. RESULTS: Upon reducing the coefficient of friction and enhancing the tightening speed, the angle of turn increased at the target torque. As the angle of turn increased, the elastic energy and preload also increased. Additionally, by increasing the coefficient of friction, the frictional dissipation energy increased but the efficiency decreased, whereas the increase in tightening speed insignificantly affected efficiency. CONCLUSION: The results of this study indicate that the coefficient of friction is the most influential factor on efficiency. Increasing the tightening speed lowered the response rate to the frictional resistance, thus diminishing the coefficient of friction and slightly increasing the preload. Increasing the tightening speed has the same result as reducing the coefficient of friction.

Cementogenesis in Patients with Localized Aggressive Periodontitis.

OBJECTIVES: The aim of this study was to determine the cementum thickness in the first molars of patients with localized aggressive periodontitis (LAP) compared to healthy individuals. MATERIALS AND METHODS: This case-control study compared eight first molar teeth affected by LAP with eight third molar teeth of healthy individuals. The teeth were disinfected by immersion in 10% buffered formalin solution for three days and were then sectioned. External mesial root surfaces (middle one-third) were evaluated under a stereomicroscope by a blinded pathologist to determine the mean thickness of cementum. SPSS software (version 16.0) and t-test were used for statistical analysis. RESULTS: Histological examination revealed a significant difference between the two groups in terms of the amount of cementogenesis (P<0.001) .The thickness of cementum was higher in the control group (105.16±11.5 µm) than in LAP patients (86.44±7.3 µm). CONCLUSION: This study demonstrated the presence of cementum hypoplasia in mesial root surfaces of first molars affected by LAP.

Isolation and Assessment of Mesenchymal Stem Cells Derived From Bone Marrow: Histologic and Histomorphometric Study in a Canine Periodontal Defect.

The aim of the present study was to investigate an isolation procedure to culture mesenchymal stem cells derived from bone marrow and evaluate their potential in periodontal regeneration. Potential stem cells from bone marrow, aspirated from the iliac crest of nine mongrel canines 1 to 2 years of age, were cultivated. After the examination of surface epitopes of the isolated cells, the total RNA from osteogenic, adipogenic, and chondrogenic cell cultures were analyzed by reverse transcription polymerase chain reaction (RT-PCR) to confirm stem cell gene expressions. 2 × 10(7) mL of the stem cells were loaded on 0.2 mL of anorganic bovine bone mineral (ABBM) granules. In each animal, bilateral acute/chronic intrabony periodontal defects were created surgically and by placement of ligatures around the cervical aspect of the teeth. At week 5, after flap debridement, the bilateral defects were randomly assigned to 2 treatment groups: the control group received ABBM, and the test group received BMSCs-loaded ABBM. Eight weeks after transplantation, regenerative parameters were analyzed histologically and histometrically. The RNA expressions confirmed the cultivation of mesenchymal stem cell. More new cementum and periodontal ligament (PDL) were measured in the test group (cementum: 3.33 ± 0.94 vs 2.03 ± 1.30, P = 0.027; PDL: 2.69 ± 0.73 vs 1.53 ± 1.21, P = 0.026). New bone formation was similar in both groups (2.70 ± 0.86 vs 1.99 ± 1.31; P = 0.193). Mesenchymal stem cells derived from bone marrow should be considered a promising technique for use in patients with periodontal attachment loss and merits further investigations.

Inactivation of Aggregatibacter actinomycetemcomitans by two different modalities of photodynamic therapy using Toluidine blue O or Radachlorin as photosensitizers: an in vitro study.

Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans) is one of the periodontopathogens strongly associated with aggressive periodontitis. The aim of this investigation was to compare the effect of laser and light-emitting diode on the photodynamic inactivation of A. actinomycetemcomitans. Eighty-four samples of bacterial suspensions (200 µL) were prepared and divided in seven groups: control group (no treatment), laser group (indium-gallium-aluminum-phosphate laser with wavelength of 662 ± 0.1 nm, energy density of 6 j/cm(2), and irradiation time of 34 s), light-emitting diode (LED) group (wavelength 625-635 nm, energy density 6 j/cm(2), time of irradiation 30 s), Toluidine blue O (TBO) group (0.1 mg/mL), Radachlorin group (0.1 %), Radachlorin + laser group (after pre-irradiation time of 10 min, laser was irradiated), and TBO + LED group (after preirradiation time of 10 min, LED was irradiated). Then, 100 µL of each sample was cultured in brain heart infusion (BHI) plates and incubated for 48-72 h in microaerophilic atmosphere for colony counting. Application of Radachlorin + laser resulted in a significant decrease in the concentration of A. actinomycetemcomitans (P values <0.05). Photodynamic therapy with laser + Radachlorin was more effective than that of LED + TBO in suppression of this microorganism (P value <0.05). Within the limits of this study, it can be concluded that photodynamic inactivation using laser and Radachlorin was more effective than that of LED and TBO in eradication of A. actinomycetemcomitans.

Lactobacillus crustorum KH: novel prospective probiotic strain isolated from Iranian traditional dairy products.

In recent years, exploring novel probiotic strains for therapeutic intervention has been raised due to the significant increase in market demand. This study aimed to investigate the certain probiotic properties of 15 Lactobacillus isolates from Iranian traditional dairy products. Among them, a novel potential probiotic strain was isolated and identified as Lactobacillus crustorum. The characteristics of potential probiotics were examined in terms of resistance to acidity, bile, and salinity as well as antibiotic tolerance and antibacterial activity. L. crustorum KH has shown tolerance property to bile (0.3 % w), acidity (pH 2-9), and salinity (1-5 % NaCl) and strong antibacterial activity against tested enteropathogens by well-diffusion assay. Furthermore, in vivo study and histological assays were performed to study whether live and heat-killed cells of L. crustorum KH are able to protect against the challenge of Escherichia coli O157:H7 in the gastrointestinal tract of mice used as an experimental model. Therefore, heat-killed and live cells of L. crustorum KH were inoculated by gavage to different groups of 4-6-week-old female BALB/c mice in doses of 10(8) colony-forming unit (CFU)/dose. Thereafter, these mice were challenged with E. coli O157:H7 also inoculated in the gastrointestinal tract (GIT) of the animals. The results showed that heat-killed cells of L. crustorum KH exert a protective effect against E. coli O157:H7 colonization at different degrees, being lower than that produced by viable cells.

The efficacy and prophylactic characteristics of omega-3 fatty acids in experimental gingivitis in rats.

OBJECTIVE(S): Gingivitis is an inflammatory disease that affects tooth-supporting tissues and is caused by a microbe-immune response. The aim of this study was to evaluate the effects of omega-3 fatty acids on immune system regulation and the prevention and treatment of gingivitis using an animal model. MATERIALS AND METHODS: Gingival inflammation was induced by lipopolysaccharide (LPS) injection. Forty adult male rats were divided into four equal groups: 1. Negative control group (sterile saline was injected into gingival tissue followed by oral gavage with saline); 2. Positive control group (LPS injection was followed by oral gavage with saline); 3. Treatment group (LPS injection was followed by oral gavage with omega-3); 4. Prophylactic group (oral gavage with omega-3 was followed by LPS injection). After 24 days, the rats were sacrificed and histological tissue samples were randomly evaluated for the inflammatory tissue changes. Tumor necrosis factor-α (TNF-α) and interleukin-1ß (IL-1ß) levels were measured by ELISA. RESULTS: The levels of IL-1ß and TNF-α in the prophylactic group and the level of TNF-α in the treatment group were significantly lower than those in the positive control group (P<0.05). The severity of inflammation was normal, slight, moderate, and severe in the negative control group, prophylactic group, treatment group, and positive control group, respectively. ANOVA was used for the statistical analyses, with P<0.05 regarded as significant. CONCLUSION: Prior consumption of omega-3 fatty acids is effective in reducing inflammation in induced rat gingivitis, resulting in a decreased level of biomarkers and fewer destructive effects.

Effects of two types of anorganic bovine bone on bone regeneration: a histological and histomorphometric study of rabbit calvaria.

OBJECTIVE: The purpose of this study was to evaluate the efficacy of two types of bone substitutes, Bio-Oss and NuOss, for repair of bone defects. MATERIALS AND METHODS: This study was performed on the calvaria of 14 New Zealand rabbits. The 6mm critical size defect (CSD) models of bone regeneration were used. Three CSDs were created in each surgical site. The first defect was filled with NuOss, the second one with Bio-Oss and the third one remained unfilled as the control. After healing periods of one and two months (seven animal for each time point), histological and histomorphometric analyses were carried out to assess the amount of new bone formation, presence of inflammation, foreign body reaction and type of new bone. Qualitative variables were analyzed by multiple comparisons, Wilcoxon, Friedman and Mann Whitney tests. Quantitative variables were analyzed using the Mann-Whitney and Wilcoxon tests. Level of statistical significance was set at 0.05. RESULTS: The level of inflammation was not significantly different at four and eight weeks in the Bio-Oss (P=0.944), NuOss (P=1.000) and control groups (P=0.71). At four weeks, foreign body reaction was not observed in Bio-Oss, NuOss and control groups. There was no significant difference in the type of the newly formed bone at four and eight weeks in any group (P=0.141 for Bio-Oss, P=0.06 for NuOss and P=0.389 for the control group). CONCLUSION: Deproteinized bovine bone mineral can be used as a scaffold in bone defects to induce bone regeneration.