The Clinical Effectiveness of Calcium Hydroxide in Root Canal Disinfection of Primary Teeth: A Meta-Analysis.

BACKGROUND The aim of this research was to systematically analyze the effectiveness of calcium hydroxide compared to formocresol (FC) and camphor phenol (CP) in root canal disinfection of primary teeth. MATERIAL AND METHODS The meta-analysis was based on the participants, interventions, control, outcome (PICO) study design principle and 16 randomized-controlled clinical trials published from January 2000 to August 2018. The data heterogeneity of each study was assessed by the Q-test. The odds ratio and 95% confidence interval (CI) were calculated based on the heterogeneity results by Revman software. RESULTS Sixteen randomized-controlled clinical trials of 3047 primary teeth were included in this meta-analysis. There were significant differences of clinical effectiveness between calcium hydroxide and FC in root canal disinfection of primary teeth (OR=3.37; 95% CI range: 2.54-4.48, P<0.01) and endodontic inter-appointment emergencies (EIAE) after disinfection for 7 days (OR=0.26; 95% CI range: 0.16-0.42, P<0.01). However, there was no statistical difference of EIAE, after disinfection of primary teeth for 48 hours, between calcium hydroxide and FC (OR=0.62; 95% CI range: 0.34-1.11, P=0.11). There were significant differences of clinical effectiveness between the calcium hydroxide and CP in root canal disinfection of primary teeth (OR=5.50; 95% CI range: 3.36-8.98, P<0.01). CONCLUSIONS This meta-analysis indicated that the effectiveness of calcium hydroxide as root canal disinfectant in primary teeth was more effective than that of FC and CP.

Effectiveness of the ozone application in two-visit indirect pulp therapy of permanent molars with deep carious lesion: a randomized clinical trial.

OBJECTIVES: The aim of this randomized, three-arm parallel, single-blinded clinical trial was to evaluate the clinical and microbiological effectiveness of the ozone application in two-visit indirect pulp therapy. MATERIALS AND METHODS: One hundred five lower first molar teeth with deep caries lesion were included and randomly assigned three groups to apply the two-visit indirect pulp therapy. Treatment procedure was applied without any disinfectant (control), with 60-s 2% chlorhexidine digluconate (CHX) or 60-s ozone application. In four different stages (after initial excavation, ozone/CHX application before the temporary restoration, 4 months later immediately after removing temporary restoration, and final excavation), dentin humidity, consistency, and color properties were recorded to evaluate the clinical characteristics of the tissue, and standard dentin samples were collected for the microbiological analysis of mutans streptococci, lactobacilli, and the total number of colony-forming units. The data were analyzed by using Mann-Whitney U test for multiple comparisons. RESULTS: The remaining dentin became harder, drier, and darker after 4 months in all groups. However, CHX and ozone application were statistically better than the control group (p < 0.05). There was a gradual decrease in the total number of microorganisms in all groups. While cavity disinfectant applications were improved the antibacterial efficacy (control, 79.11%; CHX, 98.39%; ozone, 93.33%), CHX application exhibited a greater significant reduction than both groups (p = 0.000). CONCLUSION: The two-visit indirect pulp therapy yielded successful results for all study groups. However, CHX would be conveniently preferable due to improving the treatment success. CLINICAL RELEVANCE: The two-visit indirect pulp therapy applied with cavity disinfectant is a proper alternative treatment procedure in deep carious lesions, instead of conventional technique.

Evaluation of the Efficacy of Different Mixing Techniques and Disinfection on Microbial Colonization of Polyether Impression Materials: A Comparative Study.

AIM: This study aims to determine the role of mixing techniques of polyether impression materials and efficacy of disinfection on microbial colonization of these impression materials. MATERIALS AND METHODS: Polyether impression material was mixed using two methods: First by hand mixing (group I) and second using an automixer (group II) with a total of 100 samples. Four microbial strains were studied, which included Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans. After incubation, the bacterial colonies were counted, and then, disinfectant solution was applied. The effect of disinfection solution was evaluated for each specimen. RESULTS: The surface of polyether impression materials mixed with an automixer has less number of voids and overall a smoother surface as compared with the hand-mixed ones. On comparing the disinfection procedures, i.e., specimens without any disinfection and specimens after disinfection, statistically highly significant difference was seen between all the groups. CONCLUSION: We can conclude that impression mixing procedures are important in determining the surface characteristics of the impression and ultimately the colonization of bacteria and also determine the importance of disinfection on microbial colonization. CLINICAL SIGNIFICANCE: This study emphasises the deleterious role of nosocomial infections and specific measures that should be taken regarding the prevention of such diseases. Dental impressions are proved to be a source of such infections and may lead to transmission of such diseases. Thus, proper measures should be taken right from the first step of impression taking to minimizing and preventing such kind of contaminations in clinical practice.

[Clinical and laboratory grounding of using medication based on the antiseptic troklosene to treat patients with chronic generalized periodontitis of the ii and iii degrees of severity].

OBJECTIVE: Introduction: Periodontal diseases take second place in the world among dental diseases and tend to be ubiquitous regardless of age, sex and place of residence. According to the modern point of view inflammatory periodontal diseases refer to infectious chronic inflammatory diseases, therefore, the normalization of the microflora of the oral cavity is an essential condition for their rational therapy. The aim: To increase the effectiveness of conservative treatment of chronic generalized periodontitis of the II-nd and III-rd severity using the medication based on the antiseptic Troklosene. PATIENTS AND METHODS: Materials and methods: 34 patients of age 45 to 55 years who were diagnosed with chronic generalized periodontitis of the IIInd and IIIrd degree of severity were examined and treated. All patients reported signs of the disease for 3-15 years. Patients of the study group by simple randomization were divided into two subgroups, depending on the therapeutic treatment performed. The I-st subgroup -16 patients treated with the additional use of the medication based on the antiseptic Troklosene, the IInd subgroup - 18 patients who were treated without using this drug. RESULTS: Results: Analyzing the results after the treatment in the patients of the I -st and II -nd subgroup, they noted a decrease in PMA index, Green-Vermillion index, bleeding index. Pathological mobility of teeth decreased to the I degree. The hygienic condition of the oral cavity was characterized in patients of both subgroups after treatment as satisfactory. In patients of the Ist subgroup (with the additional use of the medication based on the antiseptic Troklosene), after the 5th visit there were signs of remission, and in the IInd subgroup (using standard base therapy), after 7 visits, there were signs of clinical remission. With the additional use of the drug based on the antiseptic Troklosene, in contrast to the traditional therapy, a change in the bacterial ratio of microorganisms occurred, which influenced a significant decrease in the total bacterial mass. CONCLUSION: Conclusion: The best results were obtained in the Ist subgroup, where along with the standard base therapy, the supplement of based on the antiseptic Troklosene was used additionally. Introduction to the treatment regimen for patients with chronic generalized periodontitis with II and III severity of the drug based on the antiseptic Troklosene contributed to a stable clinical effect, as evidenced by the dynamics of clinical indicators and the reduction in the number of visits. Also, a change in the bacterial ratio of microorganisms with a significant decrease due to Enterobacterium spp. is noted. To maintain this result, it is recommended to continue the use of the drug based on the antiseptic Troklosene with a frequency of 4 times per day within 7 days after the end of treatment.

Phosphate buffer-stabilized 0.1% chlorine dioxide oral rinse for managing medication-related osteonecrosis of the jaw.

PURPOSE: This is a review of the literature on nonsurgical treatment of non-healing medication related osteonecrosis of the jaw (MRONJ) utilizing a phosphate buffer-stabilized 0.1% chlorine dioxide mouthrinse. METHODS: A literature search in PubMed revealed only six case reports. MRONJ lesion site description, patient's medication history, the healing time, and the MRONJ treatment protocol followed by those authors were recorded. Additional literature review of the scientific mechanism, risks and benefits, safety and efficacy of the phosphate buffer-stabilized 0.1% chlorine dioxide mouthrinse was also performed and discussed. RESULTS: Many of the authors of the published case reports utilized 0.12% chlorhexidine as the initial mouthrinse, but the lesions did not decrease in size. After switching to a phosphate buffer-stabilized 0.1% chlorine dioxide mouthrinse for a duration ranging from 1-12 months, there was complete healing of the MRONJ lesions in all of the cases. The phosphate buffer-stabilized 0.1% chlorine dioxide mouthrinse can be helpful in the management of active MRONJ lesions as well as the prevention of recurrent MRONJ lesions in the susceptible patient population. CLINICAL SIGNIFICANCE: This literature review supports the use of phosphate buffer-stabilized 0.1% chlorine dioxide mouthrinse in the management of MRONJ lesions either as a first line of therapy or after 0.12% chlorhexidine had not been effective.

Effectiveness of chemical disinfection on biofilms of relined dentures: A randomized clinical trial.

PURPOSE: To evaluate the effect of disinfection with sodium perborate or chlorhexidine (when combined with brushing) on the removal of biofilm in relined dentures. METHODS: Swabs were collected 48 hours after the relining procedure and at the follow-up time intervals of 7, 15, 30, 90, and 180 days. The dentures' surface roughness was measured at the same times. 45 subjects were randomly divided into three groups of 15 subjects each. The control group brushed with coconut soap and a soft toothbrush. The sodium perborate group followed the same procedure and also disinfected with sodium perborate solution for 5 minutes per day. The chlorhexidine group followed the control group procedure and disinfected with 2% chlorhexidine digluconate solution for 5 minutes per day. The number of colony forming units and the surface roughness were evaluated statistically by 2-way repeated-measure ANOVA (α = 0.05). RESULTS: The control group dentures exhibited similar levels of microbial cells throughout the experiment. However, after 15 days, no microbial growth was observed on the dentures for which either disinfection agent was used. There were no statistically significant differences in superficial roughness between the groups (P = 0.298). The disinfection agents used, combined with brushing, were able to remove the relined dentures' biofilm after 15 days of disinfection. Roughness was not a predominant factor in CFU reduction.

Should Surgical Burs Be Used as Single-Use Devices to Avoid Cross Infection? A Case-Control Study.

OBJECTIVE: The purpose of this study was to evaluate and compare the rate of bacterial contamination of reused and new unused burs after different sterilization sessions. MATERIALS AND METHODS: The test group consisted of 40 used fissure burs, and the control group of 40 unused new fissure burs (total n = 80). The burs from both groups were precleaned according to standard protocols and then subjected to two sterilization sessions (high- and low-steam pressure autoclaving). After each sterilization session, the burs were transferred into incubation tubes which contained thioglycollate culture medium and were monitored daily for a period of 48 h to detect any bacterial growth. Data were collected and statistical analysis was done using Fisher's exact test. RESULTS: Of the 40 burs of the test group, 2 burs (5%) showed positive bacterial growth, whereas no bur from the control group showed any sign of bacterial growth after high-pressure autoclaving. The colony structure and Gram staining were compatible with the growth of Staphylococcus epidermis. After a second sterilization session at low-pressure steam autoclaving, no bacterial growth was observed for the test group, but 1 bur (2.5%) from the control group showed bacterial growth and Gram-positive staining matched well with the growth of Brevibacterium species. CONCLUSIONS: The new and unused burs were 100% sterile after high-pressure steam autoclaving, whereas 5% of the reused burs appeared positive with bacterial contamination. After low-pressure steam autoclaving, reused burs were 100% sterile, but 1 new bur demonstrated bacterial contamination.

The effect of the local use of chlorhexidine in surgical treatment of experimental peri-implantitis in dogs.

AIM: To evaluate the effect of surgical treatment of experimental peri-implantitis at implants with different surface characteristics using different anti-infective procedures. MATERIAL AND METHODS: Four implants with different surface characteristics (A: TiOblast, B: OsseoSpeed, C: AT-I, D: TiUnite) were installed in a randomized order in each side of the mandible in 6 labrador dogs 3 months after tooth extraction. Experimental peri-implantitis was induced 3 months later. Surgical treatment of peri-implantitis was performed. The implants were cleaned with gauze soaked in either saline (control) or chlorhexidine (test). Clinical and radiographical examinations were performed and microbiological samples were taken during a 6-month period after surgery. Biopsies were obtained and prepared for histological analysis. RESULTS: Clinical signs of soft tissue inflammation were reduced after surgical therapy in most test and control sites. While the analysis of bone level alterations in radiographs together with histological and microbiological assessments of resolution of peri-implantitis lesions failed to demonstrate statistically significant differences between test and control procedures, the evaluations disclosed significant differences between implant D and implants A, B and C on treatment outcome. CONCLUSION: It is suggested that (i) the local use of chlorhexidine has minor influence on treatment outcome, (ii) resolution of peri-implantitis following surgical treatment without the adjunctive use of local and systemic antimicrobial agents is possible and (iii) the results are influenced by implant surface characteristics.

Treatment of periimplant mucositis: a systematic review of randomized controlled trials.

OBJECTIVE: To determine the most effective treatment for periimplant mucositis in patients with dental implants compared with a control group. MATERIALS AND METHODS: A PubMed (MEDLINE) literature search was made of articles published up until October 2013. Randomized controlled trials (RCTs) were stratified according to their level of quality using the Jadad scale and levels of evidence (University of Oxford). RESULTS: The combinations of search terms resulted in a list of 371 titles. Of these, 114 references were finally reviewed. Finally, 7 RCTs fulfilled the inclusion criteria and were thus selected for inclusion in the systematic review. Chlorhexidine, the administration of azithromycin, and glycine powder air polishing are not effective for the treatment of periimplant mucositis. The only effective treatment seems to be the use of toothpaste with 0.3% triclosan. CONCLUSION: Definitions of periimplant mucositis vary in the literature, and no clear criteria have been established regarding the diagnosis and treatment of this disorder. It highlights our lack of uniform treatment and need to establish additional research to fully provide effective treatments for this common condition. More, larger, and longer-term RCTs are needed in this periimplant disease.

Significance of biofilms in dentistry.

In the past decades significant scientific progress has taken place in the knowledge about biofilms. They constitute multilayer conglomerates of bacteria and fungi, surrounded by carbohydrates which they produce, as well as substances derived from saliva and gingival fluid. Modern techniques showed significant diversity of the biofilm environment and a system of microbial communication (quorum sensing), enhancing their survival. At present it is believed that the majority of infections, particularly chronic with exacerbations, are a result of biofilm formation, particularly in the presence of biomaterials. It should be emphasised that penetration of antibiotics and other antimicrobial agents into deeper layers of a biofilm is poor, causing therapeutic problems and necessitating sometimes removal of the implant or prosthesis. Biofilms play an increasing role in dentistry as a result of more and more broad use in dental practice of plastic and implantable materials. Biofilms are produced on the surfaces of teeth as dental plaque, in the para-nasal sinuses, on prostheses, dental implants, as well as in waterlines of a dental unit, constituting a particular risk for severely immunocompromised patients. New methods of therapy and prevention of infections linked to biofilms are under development.

The disinfection of impression materials by using microwave irradiation and hydrogen peroxide.

STATEMENT OF PROBLEM: Microwave irradiation and immersion in solutions have been recommended for denture disinfection. However, the effect of dry conditions and impression materials has not been completely evaluated. PURPOSE: The purpose of this study was to evaluate the effectiveness of microwave irradiation and hydrogen peroxide for the disinfection of dental impression materials. MATERIAL AND METHODS: Specimens (diameter 10 mm, thickness 2 mm) were made with polyvinyl siloxane. Experimental groups were treated with hydrogen peroxide (group H), microwave irradiation (group M), and a combination of both hydrogen peroxide and microwave irradiation (group MH) for 1 minute, 2 minutes, and 3 minutes. The control group was untreated. The total sample size was 120. The specimens were divided into 2 groups, those exposed to Streptococcus mutans and those exposed to Escherichia coli. The disinfection effect and physical properties (contact angle, compatibility with gypsum, strain in compression, tear strength) were evaluated. RESULTS: All 3 groups (H, M, MH) were effective in reducing the number of colony forming units (CFU) per unit volume (mL) for both S mutans and E coli compared with the control. The most significant reduction in the CFU/mL of both bacteria was noted in the MH group and was used to compare either treatment alone (P<.05). No statistically significant difference was noted between the control and treatment groups in terms of all of the physical properties tested (P>.05). CONCLUSIONS: Microwave irradiation was identified as a useful disinfection method against S mutans and E coli, especially when combined with H2O2, without adversely affecting the physical properties of dental impression materials.

Effectiveness of three antimicrobial mouthrinses on the disinfection of toothbrushes stored in closed containers: a randomized clinical investigation by DNA Checkerboard and Culture.

OBJECTIVES: The aim of this in vivo study was to evaluate the efficacy of three antimicrobial solutions on the disinfection of toothbrushes after storage in closed containers. MATERIALS AND METHODS: Sixteen healthy subjects were enrolled in this randomized cross-over clinical investigation. The study was conducted in four phases, in which mouthrinses (chlorhexidine gluconate-based or cetilpiridinium-based) and sterile tap water (control group) were used to individually store used toothbrushes in closed containers during 7 days of toothbrushing. Five toothbrushes were used as negative control for bacterial colonisation before contact with oral cavity. Conventional culture and DNA Checkerboard hybridization were used to detect bacterial contamination on the toothbrushes. Subsequently, the number of bacterial species on the bristles was estimated by the DNA Checkerboard method. RESULTS: One toothbrush presented bacterial contamination in the negative control test. Both culture and DNA Checkerboard showed positive signals of bacterial contamination in the toothbrushes with no differences in the frequency of detection. The control group showed higher total bacterial counts when compared with the mouthrinse groups. Porphyromonas gingivalis had the highest bacterial count followed by Parvimonas micra. CONCLUSION: Culture and DNA Checkerboard showed positive signals of bacterial contamination. Mouthrinses that contains 0.12% of chlorhexidine gluconate were more effective in reducing bacterial colonisation on the toothbrushes.

Survival of microorganisms on complete dentures following ultrasonic cleaning combined with immersion in peroxide-based cleanser solution.

OBJECTIVES: To compare ultrasonic cleaning combined with immersion in a commercially available peroxide-based cleanser solution (Polident(®) ) with other denture cleaning methods, we examined the quantity of micro-organisms that survived on dentures before and after various cleaning methods. SUBJECTS AND METHODS: One hundred complete dentures belonging to 50 nursing home residents (mean age, 84.6 years) were randomly assigned to five groups according to the cleaning method employed: (A) immersion in Polident(®) solution alone, (B) brushing with water, (C) ultrasonic cleaning with water, (D) method (A) followed by method (B) and (E) ultrasonic cleaning combined with immersion in Polident(®) solution. Before and after the dentures had been cleaned, denture biofilm was collected from the mucosal surface of each lateral half of the examined dentures. The collected micro-organisms were cultured, presumptively identified by standard methods and quantified. Comparisons between the five cleaning methods were carried out using the Kruskal-Wallis test and Dunn's multiple comparisons test. RESULTS: The denture cleaning methods involving the use of Polident(®) solution (methods A, D and E) were significantly more effective at denture disinfection than the other methods (p < 0.05); in particular, the quantity of Candida spp. was lowest after method E (median, 0.00; significantly lower than those observed after methods A, B and C; p < 0.05). CONCLUSION: It was concluded that ultrasonic cleaning combined with immersion in a peroxide-based cleanser solution effectively reduces the quantity of micro-organisms surviving on dentures and is a suitable method for elderly individuals who find brushing their dentures difficult.

A microbiological assessment of the oral hygiene of 24-72-month-old kindergarten children and disinfection of their toothbrushes.

BACKGROUND: The objective of this study is to assess the index of decayed, missing and filled teeth (DMF-T), habit of brushing teeth, and the microbiological agents accumulating on the children's toothbrushes for 4 weeks and response of these agents to disinfection via a chlorhexidine solution, then compare those results with the education and income levels of the children's parents. METHOD: Included in the study were 187 children (96 in the control group and 91 in the experiment group - chlorhexidine) chosen randomly from 600 kindergarten children whose ages ranged from 24 months to 72 months. The children selected had not taken any antibiotics, antimicotics for three months and dental treatments during this trial. The distribution of these children to the groups was also done randomly. After performing a survey for the education, occupation, and income status of the parents, the children were examined and the number of decayed teeth was recorded. The children were given toothbrushes, toothpaste (with fluroide), and the solutions (including distilled water and chlorhexidine) for four weeks under the condition that toothbrushes were returned at the end of each week. The 14 different microbiological agents observed as a result of the assessment of the samples taken in the first week were also included in the assessments of the samples taken over the four-week period. RESULTS: The decrease in the DMF-T index was found to be meaningful according to the differences in education, income, and occupation status of the parents. Of all the samples taken from the toothbrushes, the bacteria with the greatest rate of reproduction included Streptococcus mutans, Escherichia Coli, Pseudomonas aeuroginosa, Enterococcus spp, Staphylococcus epidermidis and Candida albicans. Except for Candida albicans, the other microorganisms taken as samples from the toothbrushes reproduced less overall. In the group using the solution with chlorhexidine, a meaningful decrease in bacterial reproduction was discovered compared to the control group. CONCLUSION: The findings of this study show that the education, occupation, and socioeconomic situations of the parents should be considered when discussing children's oral and dental health. Moreover, the study shows that disinfection of toothbrushes in order to prevent reinfection and contamination oral flora with the bacteria again is important in terms of preventive medicine and family-children health.

Frequently asked questions in direct pulp capping of permanent teeth.

UNLABELLED: Direct pulp capping is a proven method of preserving tooth vitality of a mature permanent tooth in cases of pulp exposures. The indications for this treatment, treatment modalities and materials are discussed in this paper. CLINICAL RELEVANCE: This paper answers many of the frequently asked questions by general practitioners, dental students and specialists about direct pulp capping.

Tips for maintaining sterilization in your orthodontic work station.

Sterilization and disinfection have been a matter of concern amongst dental health care workers since long. Delicate materials, electrical parts, orthodontic pliers, orthodontic wire cutters, are to be treated according to the manufacturer's instructions to safe guard the life of the instrument as well as to claim warranty for any damage incurred. Sterilization procedures used in Orthodontics should be simple but effective and of relatively short duration so that there is a readily available supply of sterile instruments and materials. The procedure should not cause any appreciable damage to dental instruments and other materials. An attempt has been made through this article, to provide information concerning methods and means of disinfection and sterilization of orthodontic clinics, instruments, materials and also waste disposal which can be adopted in private clinics as well as in hospital set ups.

Photoactivated disinfection using light-emitting diode as an adjunct in the management of chronic periodontitis: a pilot double-blind split-mouth randomized clinical trial.

AIM: This split-mouth double-masked randomized controlled clinical study evaluated the effectiveness of photoactivated disinfection (PAD) using light-emitting diode (LED) as an adjunct in the management of patients affected by moderate to severe chronic periodontitis. MATERIALS AND METHODS: Sixteen patients affected by moderate to severe chronic periodontitis were enrolled. After scaling and root planing (SRP), each quadrant was assigned to one of the following groups: LED group (625-635 nm, maximum power density: 2000 mW/cm(2) ), photosensitizer group (tolouidine blue O, 0.1 mg/ml), PAD group (photosensitizer and LED) and control group (no adjunctive treatment). The adjunctive treatments were repeated after 7 and 14 days. The clinical parameters of bleeding on probing, probing pocket depth and clinical attachment level were measured at baseline and 1 and 3 months after SRP. RESULTS: At 1 and 3 months, all groups showed significant improvements with regard to all clinical parameters compared to baseline (all p: <0.001). There were no significant differences among groups in terms of changes of clinical parameters in any time interval (all p > 0.05). CONCLUSION: The application of PAD using LED with the current setting did not have additional effects on clinical parameters in patients diagnosed with moderate to severe chronic periodontitis compared with SRP alone.

Establishment of an optimized ex vivo system for artificial root canal infection evaluated by use of sodium hypochlorite and the photodynamic therapy.

AIM: To establish a refined model of artificially infected root canals and confirm its suitability as a sensitive ex vivo method to assess the efficacy of disinfecting agents. Disinfection was evaluated using sodium hypochlorite (NaOCl), either blocked or unblocked by sodium thiosulphate, and a recently promoted method of disinfection, the antibacterial photodynamic therapy (PDT). METHODOLOGY: The roots of bovine incisors were sectioned into three parts, the canals of coronal and middle regions were filled with a suspension of Enterococcus faecalis and the apical region with culture medium. After 7 days, coronal sections were disinfected using NaOCl (0.5%, 1.0% and 3.0% for 30, 60 and 600 s) or a system for photoactivated chemotherapy (PACT; Cumdente, Tübingen, Germany) for antibacterial PDT. Apical sections served as sterile controls and middle sections as bacterial growth controls. In half of the NaOCl-treated specimens, disinfection was arrested. Dentine chips from biopsies at different depths from the central canal towards the periphery were plated and assessed for colony-forming units (CFU). Disinfection was considered biologically relevant if the reduction of CFU was at least three log10 orders of magnitude. RESULTS: Colony-forming units of 10³ - 104 in growth controls indicated effective artificial infection. A biologically relevant reduction of CFU was accomplished with unblocked NaOCl, but not after blocking with NaOCl nor with PDT. CONCLUSIONS: The system reliably detected disinfection of the root canal and dentinal tubules and proved suitable for ex vivo testing of root canal disinfection. The effect of NaOCl depended on the duration of impact. Under the present experimental conditions, the antibacterial PDT system did not achieve sufficient disinfection.

Ex vivo killing of Enterococcus faecalis and mixed plaque bacteria in planktonic and biofilm culture by modified photoactivated disinfection.

AIM: To compare the efficacy of conventional and modified photoactivated disinfection (PAD) against Enterococcus faecalis and mixed plaque bacteria in suspension and biofilms. METHODOLOGY: Enterococcus faecalis (four strains) and mixed plaque bacteria from three adult volunteers were suspended in water, added to methylene blue (MB, 15 µmol L⁻¹), MB mixed with 0.5% hydrogen peroxide and 0.05% chlorhexidine (CHX), MB mixed with 0.5% hydrogen peroxide and 0.05% EDTA or MB mixed with 0.05% EDTA and 0.05% CHX and exposed to laser irradiation from 10 s to 5 min. After exposure, samples were taken, serially diluted and grown aerobically and anaerobically on Tryptic Soy Agar plates or on blood agar plates for 24 and 72 h, respectively. For biofilm experiments, E. faecalis and mixed plaque biofilms were grown on sterile hydroxyapatite (HA) discs coated overnight with bovine dermal collagen type I for 3 weeks. After exposure to MB or MB and low concentration of EDTA with either hydrogen peroxide or CHX, the percentage of killed bacteria by PAD was evaluated using viability staining and confocal laser scanning microscope. For statistical analysis, one-way analysis of variance was performed. RESULTS: Conventional PAD killed from 90.76% to 100% E. faecalis for 3 min, but failed to kill all plaque bacteria even after 5 min of laser irradiation. In modified PAD, up to 100% of suspended E. faecalis and mixed plaque bacteria were killed after 1 min and 30 s of irradiation. Up to twenty times more biofilm bacteria were killed by modified PAD than by conventional PAD with 15 µmol L⁻¹ MB (P < 0.001) and up to eight times more than 2% CHX (P < 0.001) and 1% sodium hypochlorite (P < 0.001). CONCLUSION: Modified PAD was superior to conventional PAD against planktonic and biofilm bacteria.

Wound healing of dehiscence defects following different root conditioning modalities: an experimental study in dogs.

OBJECTIVE: The purpose of this study was to investigate the periodontal healing pattern of dehiscence-type defects following different chemical root conditioning modalities. MATERIALS AND METHODS: Buccal osseous dehiscence defects were created on six teeth of seven dogs. After dental plaque accumulation, defects were treated with sterile saline solution (control group) or one chemical conditioning modality: citric acid (CA group), ethylenediaminetetraacetic acid (EDTA group), tetracycline (TTC group), citric acid + tetracycline (CA + TTC group), or tetracycline + citric acid (TTC + CA group). After 3 months of healing, clinical parameters were evaluated, and the animals were killed. Histological sections were processed, and a computer-assisted histometric analysis was used to evaluate the formation of new cementum, new bone, and epithelial apical migration. RESULTS: All treatments yielded significant improvements in terms of probing depth decrease and clinical attachment level gain compared to baseline values; however, without significant differences among the groups (p > 0.05; one-way ANOVA). The highest amount of new cementum was noted in the EDTA group (3.72 ± 0.83 mm, 77.6 %), while the lowest amount of new bone was observed in the TTC group (0.7 ± 0.94 mm, 14.3 %). However, no statistically significant differences could be observed among the groups regarding epithelial apical migration, new cementum, and alveolar bone formation (p > 0.05). CONCLUSION: Chemical root surface conditioning did not promote any significant improvement in periodontal healing pattern of dehiscence-type defects in dogs. CLINICAL RELEVANCE: Chemical root surface conditioning after surgical debridement did not promote positive or negative effects on periodontal healing pattern of dehiscence-type defects.