Radiographic assessment of photodynamic therapy as an adjunctive treatment on induced periodontitis in immunosuppressed rats

Objective

The aim of this study was to assess radiographically the effect of photodynamic therapy (PDT) as an adjunctive treatment to scaling and root planing (SRP) on induced periodontitis in dexamethasone-induced immunosuppressed rats.

Material and Methods

The animals were divided into 2 groups: ND group (n=60): saline treatment; D group (n=60): dexamethasone treatment. In both ND and D groups, periodontal disease was induced by the placement of a ligature in the left first mandibular molar. After 7 days, ligature was removed and all animals received SRP, being divided according to the following treatments: SRP: saline and PDT: phenothiazinium dye (TBO) plus laser irradiation. Ten animals per treatment were killed at 7, 15 and 30 days. The distance between the cementoenamel junction and the height of the alveolar bone crest in the mesial surface of the mandibular left first molars was determined in millimeters in each radiograph. The radiographic values were analyzed statistically by ANOVA and Tukey''s test at a p value <0.05.

Results

Intragroup radiographic assessment (ND and D groups) showed that there was statistically significant less bone loss in the animals treated with PDT in all experimental periods compared to those submitted to SRP. Intergroup radiographic analysis (ND and D groups) demonstrated that there was greater bone loss in the ND group treated with SRP compared to the D group treated with PDT at 7 and 30 days.

Conclusion

PDT was an effective adjunctive treatment to SRP on induced periodontitis in dexamethasone-induced immunosuppressed rats.     

Adjuvant Therapy With Sodium Alendronate for the Treatment of Experimental Periodontitis in Rats

Background: This study assesses the effects of topical sodium alendronate (SA) as an adjuvant to the mechanical treatment of ligature‐induced periodontitis in rats. Methods: Ninety animals were subjected to the induction of periodontitis via the installation of a ligature around the mandibular left first molar. After 7 days, the ligature was removed, and the animals were distributed into the following groups: 1) NT group (n = 30), no treatment; 2) SRP group (n = 30), scaling and root planing (SRP) and local irrigation with physiologic saline solution; and 3) SRP/SA group (n = 30), SRP and local irrigation with SA (10^?5 M). Ten animals from each group were euthanized at 7, 15, and 30 days after treatment. Histologic and histometric analyses were performed in the furcation region. The percentage of bone in the furcation (PBF) was measured. Immunohistochemical analyses for detecting the receptor activator of nuclear factor‐κB ligand (RANKL), osteoprotegerin (OPG), tartrate‐resistant acid phosphatase (TRAP), and activated caspase‐3 were performed at the furcation region. Results: Compared with the other groups, the SRP/SA group showed less local inflammation and better tissue reparation during the entire experiment. There was more PBF in the SRP/SA group than in the other groups at days 7 and 15. Stronger OPG immunolabeling and weaker RANKL immunolabeling were observed in the SRP/SA group at 15 and 30 days. There were fewer TRAP‐positive cells in the SRP/SA group than in the NT group at all of the time points. There was no difference in the number of activated caspase‐3‐positive osteocytes among groups and time points. Conclusion: It can be concluded that topical use of SA as an adjuvant to SRP is effective in the treatment of experimental periodontitis.     

Adjunctive Antimicrobial Photodynamic Treatment of Experimentally Induced Periodontitis in Rats With Ovariectomy

Background: The aim of this study is to compare antimicrobial photodynamic therapy (aPDT) as an adjunctive therapy to scaling and root planing (SRP) for the treatment of experimentally induced periodontitis in rats with ovariectomy (OVX) that are or are not treated with estrogen replacement. Methods: A total of 270 female rats were divided into three groups: 1) normal rats; 2) rats with OVX; and 3) rats with OVX with estrogen replacement. Periodontal disease was induced through the introduction of a cotton thread around the mandibular left first molar. After 7 days, the ligature was removed, and the rats were randomly divided into the following treatment groups: 1) SRP plus saline solution; 2) SRP plus low‐level laser therapy (LLLT); and 3) SRP plus toluidine blue O irrigation followed by LLLT. Ten rats from each group were euthanized at days 7, 15, and 30 after dental treatment. Bone loss (BL) in the furcation region was evaluated using histometric and immunohistochemical analyses. Results: aPDT treatment resulted in reduced BL compared with SRP treatment at all time points. Additionally, rats treated with aPDT exhibited reduced numbers of tartrate‐resistant acid‐phosphatase–positive cells and more proliferating cell nuclear antigen–positive cells in all treatment groups regardless of estrogen status. Whereas rats treated with aPDT showed weak immunoreactivity to the receptor activator of nuclear factor‐κ B ligand at day 7 post‐treatment, strong osteoprotegerin immunoreactivity was observed at day 15 post‐treatment. Conclusion: aPDT is an effective adjunctive therapy for the treatment of periodontitis in rats with OVX that are or are not given estrogen replacement therapy.     

Periodontal response to orthodontic tooth movement in diabetes‐induced rats with or without periodontal disease

1 Background

Systemic conditions can influence orthodontic tooth movement. This study evaluates histologic periodontal responses to orthodontic tooth movement in diabetes‐induced rats with or without periodontal disease.

2 Methods

Forty Wistar rats were divided according their systemic condition (SC) into diabetic (D) and non‐diabetic (ND) groups. Each group was subdivided into control (C), orthodontic tooth movement (OM), ligature‐induced periodontitis (P) and ligature‐induced periodontitis with orthodontic movement (P+OM) groups. Diabetes mellitus (DM) was induced with alloxan monohydrate, and after 30 days, the P group received a cotton ligature around their first lower molar crown. An orthodontic device was placed in OM and P+OM groups for 7 days, and the animals were then euthanized.

3 Results

Differences in OM between D and ND groups were not significant (6.87± 3.55 mm and 6.81 ± 3.28 mm, respectively), but intragroup analysis revealed statistically significant differences between the P+OM groups for both SCs. Bone loss was greater in the D group (0.16 ± 0.07 mm²) than in the ND group (0.10 ± 0.03 mm²). In intragroup analysis of the D condition, the P+OM group differed statistically from the other groups, while in the ND condition, the P+OM group was different from the C and OM groups. There was a statistically significant difference in bone density between D and ND conditions (18.03 ± 8.09% and 22.53 ± 7.72%) in the C, P, and P+OM groups.

4 Conclusion

DM has deleterious effects on bone density and bone loss in the furcation region. These effects are maximized when associated with ligature‐induced periodontitis with orthodontic movement.     

Experimental periodontal disease treatment by subgingival irrigation with tetracycline hydrochloride in rats

Objective

The aim of this study was to compare subgingival irrigation with tetracycline hydrochloride (TTC-HCL) as adjunctive treatment to scaling and root planning (SRP) on induced periodontitis in rats.

Material and methods

In 60 rats, periodontal disease was ligature-induced at the mandibular left first molar. After 7 days, the ligature was removed and all animals were submitted to SRP, and divided into 2 groups according to the following treatment: C (n=30) - subgingival irrigation with 1 mL of saline; T (n=30) - subgingival irrigation with 1 mL of TTC-HCL (50 mg/mL). Ten animals in each group were euthanized at 7, 15 and 30 days posttreatment. The histometric values were statistically analyzed (p<0.05).

Results

In the histometric analysis, at 7, 15 and 30 days, Group T (0.72±0.05 mm², 0.57±0.14 mm², 0.62±0.07 mm²), showed less bone loss (p<0.05) than Group C (1.35±0.25 mm²; 1.40±0.31 mm²; 1.29±0.27 mm²), respectively.

Conclusions

Subgingival irrigation with TTC-HCL was an effective adjunctive treatment for periodontal disease induced in rats.     

Impact of cannabis sativa (marijuana) smoke on alveolar bone loss: a histometric study in rats

Background: Cannabis sativa (marijuana) can interfere with bone physiopathology because of its effect on osteoblast and osteoclast activity. However, its impact on periodontal tissues is still controversial. The present study evaluates whether marijuana smoke affects bone loss (BL) on ligature‐induced periodontitis in rats. Methods: Thirty male Wistar rats were used in the study. A ligature was placed around one of the mandible first molars (ligated teeth) of each animal, and they were then randomly assigned to one of two groups: control (n = 15) or marijuana smoke inhalation ([MSI] for 8 minutes per day; n = 15). Urine samples were obtained to detect the presence of tetrahydrocannabinol. After 30 days, the animals were sacrificed and decalcified sections of the furcation area were obtained and evaluated according to the following histometric parameters: bone area (BA), bone density (BD), and BL. Results: Tetrahydrocannabinol was positive in urine samples only for the rats of the MSI group. Non‐significant differences were observed for unligated teeth from both groups regarding BL, BA, and BD (P >0.05). However, intragroup analysis showed that all ligated teeth presented BL and a lower BA and BD compared to unligated teeth (P <0.05). The intergroup evaluation of the ligated teeth showed that the MSI group presented higher BL and lower BD (P <0.05) compared to ligated teeth from the control group. Conclusion: Considering the limitations of this animal study, cannabis smoke may impact alveolar bone by increasing BL resulting from ligature‐induced periodontitis.     

Effect of Hydrosoluble Chlorine–Mediated Antimicrobial Photodynamic Therapy on Clinical Parameters and Cytokine Profile in Ligature‐Induced Periodontitis in Dogs

Background: Recently, a hydrosoluble chlorine composed of sodium salts chlorine e6, chlorine p6, and purpurine‐5 has been shown to be a promising photosensitizer in antimicrobial photodynamic therapy (aPDT). The aim of this study is to evaluate the effects of adjunctive application of hydrosoluble chlorine–mediated aPDT compared with scaling and root planing (SRP) alone on clinical parameters and cytokine levels in gingival crevicular fluid of dogs with experimental periodontitis. Methods: Periodontal disease was induced by placing silk ligatures around both maxillary and mandibular teeth. After establishment of attachment loss, full‐mouth SRP was performed in all dogs. One day after SRP, each quadrant randomly received one of the following treatment modalities: hydrosoluble chlorine plus diode laser (wavelength 662 nm, power 100 mW, continuous mode, time of irradiation 20 seconds), hydrosoluble chlorine alone, laser alone, or no adjunctive treatment. The same adjunctive procedure was repeated 1 week later. Clinical parameters including periodontal probing depth, clinical attachment level, and bleeding on probing, as well as crevicular levels of interleukin‐1β and tumor necrosis factor‐α, were evaluated at baseline, at 3 weeks, and at 3 months after treatment. Results: After both 3 weeks and 3 months, all treatment groups showed significant improvement in all clinical and immunologic parameters (P <0.001). No significant differences were found between the four groups with regard to the measured parameters (P >0.05). Conclusion: Based on the results of this study, adjunctive use of hydrosoluble chlorine–mediated aPDT with the current setting has no additional effect on the clinical parameters or proinflammatory cytokine levels in ligature‐induced periodontitis.     

Clinical Effects of Potassium–Titanyl–Phosphate Laser and Photodynamic Therapy on Outcomes of Treatment of Chronic Periodontitis: A Randomized Controlled Clinical Trial

Background: The main objective of periodontal treatment is to control infection and thereby curb disease progression. Recent studies have demonstrated that adjunctive treatment procedures, such as laser irradiation or photodynamic therapy (PDT), may provide some additional benefit in the treatment of chronic periodontitis (CP). The aim of this randomized controlled trial is to clinically evaluate and compare the clinical effects of potassium–titanyl–phosphate (KTP) laser and PDT on outcomes of CP treatment. Methods: Twenty‐four patients with untreated CP were treated using a split‐mouth study design in which the teeth in each quadrant were randomly treated by scaling and root planing (SRP) alone (group A), PDT followed by SRP (group B), or KTP laser followed by SRP (group C). The periodontal pockets were exposed to a KTP laser with the following parameters: 0.8 W output power, 50 milliseconds time on/50 milliseconds time off, 30 seconds per irradiation at 532 nm and 11.7 J/cm² fluence, with a flexible fiberoptic tip with a diameter of 200 µm. The selected pockets were probed with a pressure‐controlled probe, guided by stents. Clinical periodontal parameters assessed included plaque index, gingival index, bleeding on probing (BOP), probing depth (PD), and clinical attachment level (CAL), which were recorded at baseline and at 6 months after therapy. Results: Statistical analysis demonstrated no differences between groups at baseline for all parameters (P >0.05). All treatments yielded significant improvements in terms of BOP and PD decrease and CAL gain compared to baseline values (P <0.05). Group C showed a greater reduction in PD compared to the other groups (P <0.05). In addition, group C showed a greater CAL gain compared to the other groups (P <0.05). Conclusion: In patients with CP, clinical outcomes from conventional periodontal treatment of deeper pockets can be improved by using adjunctive KTP laser.     

The effects of Lactobacillus reuteri on the inflammation and periodontal tissue repair in rats: A pilot study

ObjectiveThe aim of this study was to evaluate the effects of probiotic (PRO) Lactobacillus reuteri (DSM17938) as an adjuvant to the treatment of experimental periodontitis (EP).Material and methodsFifty-four male adult Wistar rats were included. EP was induced and maintained for 7 days. Subsequently, the ligature was removed and the animals were allocated into three different experimental groups (n = 18/group): EP – no local treatment, the animals received four systemic saline solution (SS) administrations; SRP+SS, the animals underwent SRP treatment, followed by SS administration; and SRP+PRO, the animals received SRP treatment, followed by the systemic administration of PROs (Lactobacillus reuteri ; 0.16 ml/day). Six animals from each group were euthanised at 7, 15 and 30 days. Histological and histometric analyses of alveolar bone loss (BL) and immunohistochemical analyses for TRAP, RANKL, OPG, OCN, and PCNA were performed. Shapiro–Wilk, ANOVA, post-hoc Tukey, Kruskal–Wallis, Student–Newman Keuls were performed.ResultsThe SRP+PRO group presented a reduction in inflammation. At 15 days, a lower BL was observed in the SRP+SS and SRP+PRO groups. Greater immunolabeling was noticed for PCNA at 15 days in the SRP+PRO group than in the SRP+SS group. The SRP+PRO group demonstrated a higher OCN immunolabeling pattern than the EP group at 15 and 30 days.ConclusionThe use of Lactobacillus reuteri as an adjuvant to SRP for the treatment of EP showed promising results in the control of local inflammatory responses, and enhanced the periodontal tissue repair process according to the employed concentration.     

Clinical and microbiological benefits of systemic metronidazole and amoxicillin in the treatment of smokers with chronic periodontitis: a randomized placebo-controlled study

Aim: The aim of this study was to evaluate the clinical and microbiological effects of scaling and root planing (SRP) alone or combined with metronidazole (MTZ) or with MTZ and amoxicillin (AMX) in the treatment of smokers with chronic periodontitis. Methods: A double‐blind, placebo‐controlled, randomized clinical trial was conducted in 43 subjects who received SRP alone (n=15) or combined with MTZ (400 mg 3 × per day, n=14) or with MTZ+AMX (500 mg 3 × per day, n=14) for 14 days. Clinical and microbiological examinations were performed at baseline and 3 months post‐therapy. Subgingival samples were analysed by checkerboard DNA–DNA hybridization. Results: Subjects receiving MTZ+AMX showed the greatest improvements in mean probing depth and clinical attachment level. Both antibiotic therapies led to additional clinical benefits over SRP alone in initially shallow, intermediate, and deep sites. The SRP+MTZ+AMX therapy led to the most beneficial changes in the subgingival microbial profile. These subjects showed significant reductions in the mean counts and proportions of periodontal pathogens such as Tannerella forsythia, Porphyromonas gingivalis and Treponema denticola, and the greatest increase in proportions of host‐compatible species. Conclusion: Significant advantages are observed when systemic antibiotics are combined with SRP in the treatment of smokers with chronic periodontitis. The greatest benefits in clinical and microbiological parameters are achieved with the use of SRP+MTZ+AMX.     

Clinical Effectiveness of Diode Laser Therapy as an Adjunct to Non‐Surgical Periodontal Treatment: A Randomized Clinical Study

Background: The aim of this randomized clinical study is to evaluate the effect of a 980‐nm diode laser as an adjunct to scaling and root planing (SRP) treatment. Methods: Thirty‐five patients with chronic periodontitis were selected for the split‐mouth clinical study. SRP was performed using a sonic device and hand instruments. Quadrants were equally divided between the right and left sides. Teeth were treated with SRP in two control quadrants (control groups [CG]), and the diode laser was used adjunctively with SRP in contralateral quadrants (laser groups [LG]). Diode laser therapy was applied to periodontal pockets on days 1, 3, and 7 after SRP. Baseline data, including approximal plaque index (API), bleeding on probing (BOP), probing depth (PD), and clinical attachment level (CAL), were recorded before the treatment and 6 and 18 weeks after treatment. Changes in PD and CAL were analyzed separately for initially moderate (4 to 6 mm) and deep (7 to 10 mm) pockets. Results: The results were similar for both groups in terms of API, BOP, PD in deep pockets, and CAL. The laser group showed only significant PD gain in moderate pockets during the baseline to 18‐week (P <0.05) and 6‐ to 18‐ week (P <0.05) periods, whereas no difference was found between LG and CG in the remaining clinical parameters (P >0.05). Conclusion: The present study indicates that, compared to SRP alone, multiple adjunctive applications of a 980‐nm diode laser with SRP showed PD improvements only in moderate periodontal pockets (4 to 6 mm).     

Therapeutic Effects of Systemic Vitamin K2 and Vitamin D3 on Gingival Inflammation and Alveolar Bone in Rats With Experimentally Induced Periodontitis

Background: The synergistic effects of vitamin D3 and vitamin K2 on bone loss prevention have been reported. This study evaluates the effects of vitamin D3 and vitamin K2 supplementation in conjunction with conventional periodontal therapy (scaling and root planing [SRP]) on gingival interleukin (IL)‐1β and IL‐10, serum bone alkaline phosphatase (B‐ALP) and tartrate‐resistant acid phosphatase 5b (TRAP‐5b), and calcium and alveolar bone levels in rats with experimentally induced periodontitis. Methods: Seventy‐two rats were divided into the following groups: 1) healthy; 2) periodontitis; 3) SRP; 4) SRP + vitamin D3; 5) SRP + vitamin K2; and 6) SRP + vitamins K2 and D3. Periodontitis was induced by ligature placement for 7 days, and vitamin K2 (30 mg/kg) and/or vitamin D3 (2 μg/kg) were administered for 10 days in the SRP + vitamin D3, SRP + vitamin K2, and SRP + vitamins K2 and D3 groups by oral gavage. On day 18, the animals were sacrificed, serum B‐ALP, TRAP‐5b, and calcium levels were measured, gingiva specimens were extracted for IL‐1β and IL‐10 analysis, and distances between the cemento‐enamel junction and alveolar bone crest were evaluated. Results: Alveolar bone levels in the periodontitis group were significantly greater than those in the other five groups. No significant differences were found in gingival IL‐1β and IL‐10, serum B‐ALP and TRAP‐5b, and calcium and alveolar bone levels between the groups receiving SRP and vitamins and the group receiving SRP alone. Conclusion: Within the limitations of this study, vitamin D3 and K2 alone or in combination did not affect gingival IL‐1β and IL‐10, serum B‐ALP and TRAP‐5b levels, or alveolar bone compared with conventional periodontal therapy alone.     

光动力疗法辅助治疗Ⅲ期、Ⅳ期牙周炎的临床效果评价

目的: 探讨光动力疗法（photodynamic therapy,PDT）辅助龈下刮治术（subgingival scaling and root planning,SRP）在Ⅲ、Ⅳ期牙周炎治疗中的临床效果。方法: 根据2018年牙周病新分类,选择Ⅲ期和Ⅳ期牙周炎患者,经龈上洁治1周后,记录牙周探诊深度（probing depth, PD）、牙龈指数（gingival index, GI）和探诊出血（bleeding on probing,BOP）为基线。将患者分为3组,SRP组进行SRP治疗;PDT1组在SRP后即刻对口内所有PD≥5 mm的位点进行PDT;PDT2组在SRP+PDT后6周,对原位点再进行1次PDT。基线治疗后3、6个月复查,比较PD、GI和BOP阳性率的变化。采用SPSS 22.0软件包对数据进行统计学分析。结果: 共纳入30例患者、1 289个位点。SRP组、PDT1组和PDT2组各10例患者,位点数分别为476个（36.9%）、384个（29.8%）和429个（33.3%）。3组治疗后3个月、6个月复查时,PD、GI、BOP阳性率较基线均显著降低（P<0.05）; 6个月与3个月的复查结果无显著差异。PD≥5 mm的位点,PDT1组和PDT2组可以显著降低患牙的GI和BOP阳性率（P<0.05）;PD≥7 mm时,PDT2组PD显著降低（P<0.05）。结论: 对于Ⅲ、Ⅳ期牙周炎,PDT辅助SRP治疗可以获得比单纯SRP更好的临床效果。     

Preventive effects of thymoquinone in a rat periodontitis model: a morphometric and histopathological study

Ozdemir H, Kara MI, Erciyas K, Ozer H, Ay S. Preventive effects of thymoquinone in a rat periodontitis model: a morphometric and histopathological study. J Periodont Res 2012; 47: 74–80. © 2011 John Wiley & Sons A/S Background and Objective: Thymoquinone has a variety of pharmacologic properties, including antihistaminic, antibacterial, antihypertensive, hypoglycemic, anti‐inflammatory and anti‐oxidative activities. Through its anti‐inflammatory and antioxidant properties, thymoquinone may play an important role in preventing periodontal diseases. The aim of this study was to evaluate the effectiveness of thymoquinone in preventing the initiation and progression of periodontitis in a rat periodontitis model. Material and Methods: Twenty‐four rats were randomly divided into three experimental groups: a nonligated (NL) treatment group (n = 8), a ligature‐only (LO) treatment group (n = 8) and a ligature plus thymoquinone (10 mg/kg, daily for 11 d) (TQ) treatment group. In order to induce experimental periodontitis, a 4/0 silk suture was placed at the gingival margin of the right‐mandibular first molars of the rats. Thymoquinone was administered by gastric feeding until the animals were killed on day 11. Changes in the alveolar bone levels of rats in each group were measured clinically, and tissues of rats in each group were examined histopathologically to determine inflammatory cell infiltration (ICI), osteoblast and osteoclast activities, and osteoclast morphology. Results: Alveolar bone loss around the mandibular molar tooth was significantly higher in the LO group compared with NL and TQ groups (p < 0.05). The ratio of the presence of ICI and osteoclast numbers was significantly higher in the LO group than in the NL and TQ groups (p < 0.05). Osteoblastic activity was significantly lower in the LO group than in the NL and TQ groups (p < 0.05). Conclusion: The present study showed that the oral administration of thymoquinone diminishes alveolar bone resorption in a rat periodontitis model.     

光动力疗法对慢性牙周炎龈下牙周致病菌的影响

目的：应用PeriowaveTM光动力杀菌系统对慢性牙周炎患者进行治疗,通过龈下菌斑中牙周致病菌比例的变化,评价光动力疗法（photodynamic therapy,PDT）治疗慢性牙周炎的临床效果。方法：选取60名慢性牙周炎患者,分别给予SRP＋1次PDT（A组）、SRP＋2次PDT（B组）或单纯SRP（C组）治疗。利用real-time PCR技术检测A、B、C三组在治疗前、治疗后6周、治疗后12周龈下菌斑中牙周致病菌P.g、A.a、T.f所占比例的变化。结果：治疗后6周,A、B两组牙周致病菌P.g在总菌中的比例都有非常显著降低（p〈0.01）,C组有显著降低（p〈0.05）;治疗后12周,A、B组仍有非常显著的降低（p〈0.01）,与C组相比有非常显著差异（p〈0.01）,但A、B两组之间没有差异（p〉0.05）;而仅在治疗后12周,B组的A.a相对于总菌的比例与基线相比有显著降低（p〈0.05）,且这一变化显著大于A、C两组（p〈0.05）;在治疗后6周,A、B组T.f相对于总菌含量的下降与基线相比,明显大于C组（p〈0.05）,治疗后12周,A、B两组T.f相对于总菌的含量仍有非常显著的下降（p〈0.01）,但A组和B组之间都没有差异。结论：PDT对P.g、A.a和T.f3种牙周致病菌都有杀灭作用,但P.g、T.f对PDT更为敏感,PDT可以作为治疗慢性牙周炎的辅助方法。     

Effects of Locally Administered Tiludronic Acid on Experimental Periodontitis in Rats

Background: It appears there are no studies evaluating the influence of the bisphosphonate tiludronic acid (TIL) on periodontitis. The purpose of this study is to evaluate via microtomographic, histopathologic, histometric, and immunohistochemical analyses the effects of local administration of TIL on ligature‐induced periodontitis in rats. Methods: Forty‐eight rats were divided into six groups: C (control), EP (experimental periodontitis), EP‐Saline, EP‐TIL0.1, EP‐TIL0.3, and EP‐TIL1. In EP, a ligature was placed around maxillary second molars. In EP‐TIL0.1, EP‐TIL0.3, and EP‐TIL1, TIL solutions of 0.1, 0.3, and 1 mg/kg body weight, respectively, were injected into the subperiosteal palatal area adjacent to maxillary second molars every other day. EP‐Saline received 0.9% NaCl solution instead. Animals were euthanized at day 11. Bone changes were evaluated by microtomographic and histometric analyses. Histopathologic analysis and immunohistochemical detection of tartrate‐resistant acid phosphatase (TRAP) were also performed. Data were statistically analyzed (analysis of variance or Kruskal–Wallis, P <0.05). Results: Histometric and microtomographic analyses (at buccal, interproximal, and furcation sites) demonstrated that EP‐TIL1 presented less alveolar bone loss (ABL) than EP (P <0.05), whereas EP‐TIL0.1 and EP‐TIL0.3 did not demonstrate significant differences in alveolar bone level compared to EP (P >0.05). Also, EP‐TIL1 showed significantly fewer TRAP‐positive multinucleated osteoclasts than EP and EP‐Saline (P <0.05). Conclusion: It can be concluded that locally administered TIL solution (1 mg/kg body weight) reduced alveolar bone loss in experimental periodontitis and the dosage of TIL may influence its anti‐inflammatory and antiresorptive properties.     

Effects of Probiotic Therapy on Metabolic and Inflammatory Parameters of Rats With Ligature‐Induced Periodontitis Associated With Restraint Stress

Background: This study evaluates the effects of probiotic therapy (PT) in rats with ligature‐induced periodontitis associated with restraint stress. Methods: Sixty‐four rats were divided into control, stress (STR), probiotic (PROB), periodontal disease (PD), STR‐PROB, STR‐PD, STR‐PROB‐PD, and PROB‐PD groups. The probiotic was added to the drinking water for 44 days. PD was induced by a ligature. In STR groups, the animals were subjected to restraint stress for 2.5 hours per day for 30 days. Results: Rats with PD exhibited increased alveolar bone loss (P <0.05), as well as increased levels of cyclooxygenase‐2, serum C‐terminal telopeptide (CTX), p38 mitogen‐activated protein kinase (p38), and receptor activator of nuclear factor‐κB ligand and decreased levels of osteoprotegerin (OPG). Stressed rats presented high levels of C‐peptide, corticosterone, and glucose (P <0.05). In general, the presence of stress reduced the expression of CTX and p38 (P <0.05). PT reduced alveolar bone loss in unstressed animals. It also decreased expression of CTX and induced increased expression of OPG in unstressed animals with PD. However, PT was not effective in preventing bone loss or altering the expression of inflammatory markers in stressed animals. PT decreased the number of inflammatory cells in the periodontal tissue (P <0.05). Groups with stress and PD showed decreased villous height and crypt depth. Stress seemed to prevent part of the probiotic beneficial effects on the small intestine. Conclusions: Based on the methodology used, PT may reduce tissue breakdown resulting from PD in unstressed rats. The protocol used for restraint stress influenced the immunomodulatory effects of PT in intestinal and periodontal tissues.     

Effects of Photodynamic Therapy on Clinical and Gingival Crevicular Fluid Inflammatory Biomarkers in Chronic Periodontitis: A Split‐Mouth Randomized Clinical Trial

Background: There are limited clinical experiments addressing the effects of photodynamic therapy (PDT) as an adjunct to conventional scaling and root planing (SRP) on clinical and biologic features of periodontitis. This trial compares the clinical parameters and cytokine profiles in gingival crevicular fluid of patients with moderate‐to‐severe chronic periodontitis (CP) who have been treated using SRP alone or SRP + PDT. Methods: Twenty‐two patients with two contralateral teeth affected with moderate‐to‐severe CP were selected. After SRP, the participants’ teeth were randomized to receive either no further treatment or a single application of PDT using a 638‐nm laser and toluidine blue. Although the change in probing depth was the primary outcome, bleeding on probing, clinical attachment level, gingival recession, interleukin‐1β, tumor necrosis factor (TNF)‐α, and matrix metalloproteinase 8 and 9 were also evaluated at baseline and 3 months postintervention. An oral rinse assay was also performed to determine the total levels of oral polymorphonuclear cells (PMNs) before and 3 months after the treatments. Results: Within each group, significant improvements (P <0.001) were found for all variables in 3‐month follow‐up compared with baseline. Only TNF‐α was significantly improved in the PDT + SRP versus SRP group. Total levels of PMNs were reduced for all patients compared with baseline levels (P <0.001). Conclusion: In patients with CP, a single application of PDT (using a 638‐nm laser and toluidine blue) did not provide any additional benefit to SRP in terms of clinical parameters or inflammatory markers 3 months following the intervention.     

Photodynamic Therapy During Supportive Periodontal Care: Clinical,Microbiologic, Immunoinflammatory,and Patient‐Centered Performance in a Split‐Mouth Randomized Clinical Trial

Background: This study investigates the effect of photodynamic therapy (PDT) as monotherapy during supportive periodontal therapy. Methods: A split‐mouth, randomized controlled trial was conducted in patients with chronic periodontitis (N = 22) presenting at least three residual pockets (probing depth [PD] ≥5 mm with bleeding on probing [BOP]). The selected sites randomly received the following: 1) PDT; 2) photosensitizer (PS); or 3) scaling and root planing (SRP). At baseline and 3 and 6 months, clinical, microbiologic (real‐time polymerase chain reaction analyses), cytokine pattern (multiplexed bead immunoassay), and patient‐centered (regarding morbidity) evaluations were performed. Results: All therapies promoted similar improvements in clinical parameters throughout the study (P <0.05), except that BOP was not reduced in the PS protocol (P >0.05). Lower levels of Aggregatibacter actinomycetemcomitans were observed in the PDT and SRP protocols at 3 months when compared with the PS protocol (P <0.05). An inferior frequency detection of Porphyromonas gingivalis was observed in the PDT protocol at 3 and 6 months and in the SRP protocol at 6 months from baseline (P <0.05). In addition, PDT protocol presented inferior frequency of P. gingivalis at 3 months when compared with the other therapies (P <0.05). Only patients in the PDT protocol exhibited augmented levels of anti‐inflammatory interleukin (IL)‐4 and reduced proinflammatory IL‐1β and IL‐6 throughout the study (P <0.05). Intergroup analyses showed reduced IL‐10 and increased interferon‐γ and IL‐1β levels in the PS protocol when compared with the other therapies during follow‐ups (P <0.05). No differences in morbidity were observed between the therapies (P >0.05), although the need for anesthesia was higher in SRP‐treated sites (P <0.05). Conclusion: PDT as an exclusive therapy may be considered a non‐invasive alternative for treating residual pockets, offering advantages in the modulation of cytokines.