Antibiofilm potential over time of a tricalcium silicate material and its association with sodium diclofenac

OBJECTIVES

The objectives of this study are to investigate, over time, the antimicrobial activity against polymicrobial biofilms and ability to inhibit biofilm formation, of Biodentine (BD) alone and with 5% and 10% sodium diclofenac (DC).

MATERIAL AND METHODS

The antimicrobial activity of BD alone and modified with 5% and 10% DC against polymicrobial biofilm growth in dentin was determined by a modified direct contact test. The study groups were (1) BD; (2) BD + 5% DC; and (3) BD + 10% DC. The viability of microorganisms after 1 and 4 weeks was quantified by means of an ATP assay and flow cytometry. The antibiofilm efficacy of the materials, preventing polymicrobial biofilm formation over time, was assessed by confocal laser scanning microscopy (CLSM).

RESULTS

The results obtained with both the ATP test and flow cytometry showed that BD alone and with 5% and 10% DC exerted antibiofilm activity with respect to the control, in the two evaluated times (p < 0.001). Comparison between groups showed a tendency of increased antimicrobial effect, both over time and depending on the DC concentration. These results coincide with those obtained in CLSM analysis, where efficacy increased with time and DC concentration.

CONCLUSIONS AND CLINICAL RELEVANCE

Biodentine, over time, showed antimicrobial and antibiofilm efficacy on polymicrobial biofilms. The addition of 5% and 10% DC to BD enhanced this effect, in a concentration- and time-dependent manner.

Doxycycline-functionalized polymeric nanoparticles inhibit Enterococcus faecalis biofilm formation on dentine

AIM

To evaluate in a laboratory setting the antimicrobial properties and the potential to inhibit biofilm formation of novel remineralizing polymeric nanoparticles (NPs) when applied to dentine surfaces and to ascertain the effect of the functionalization of these NPs with zinc, calcium or doxycycline.

METHODOLOGY

The antimicrobial activity and inhibition of biofilm formation of polymeric NPs were analysed on human dentine blocks that were infected with Enterococcus faecalis before or after application of NPs. LIVE/DEAD ® testing under Confocal Laser Scanning Microscopy and bacterial culturing were employed to analyse biofilm biovolume and bacterial viability. Field Emission Scanning Electron Microscopy was also employed to assess biofilm morphology. One-way anova with Welch's correction and post hoc comparison by the Games-Howell test were performed for comparisons between groups.

RESULTS

The un-functionalized NPs displayed the greatest antimicrobial activity against E. faecalis biofilms as they provided the lowest biovolume (3865.7 ± 2926.97 µm³ ; P < 0.001) and the highest dead/injured cells percentage (79.93 ± 18.40%; P < 0.001), followed by Dox-NPs (biovolume: 19,041.55 ± 17,638.23 µm³ , dead/injured cells: 45.53 ± 26.50%; P < 0.001). Doxycycline-loaded NPs had the largest values of inhibition of biofilm formation with the lowest biofilm biovolume (8517.65 ± 7055.81 µm³ ; P < 0.001) and a high dead/injured bacterial percentage (68.68 ± 12.50%; P < 0.001). Un-functionalized NPs did not reduce biomass growth (P > 0.05), but attained the largest percentage of compromised cells (93 ± 8.23%; P < 0.001), being able to disrupt biofilm formation. It also produced occlusion of dentinal tubules, potentially interfering with bacterial tubule penetration.

CONCLUSIONS

A new generation of bioactive nano-fillers (doxycycline-functionalized polymeric NPs) had antibacterial activity and occluded dentinal tubules. Incorporating these NPs into endodontic sealers may have the potential to enhance the outcome of root canal treatment.

A laboratory study of root canal and isthmus disinfection in extracted teeth using various activation methods with a mixture of sodium hypochlorite and etidronic acid

AIM

To evaluate in a laboratory setting the antibiofilm activity of several irrigating protocols including conventional irrigation, ultrasonic activation and XP-endo Finisher, with a mixture of sodium hypochlorite and etidronic acid in infected isthmuses and root canals of extracted human mandibular molar teeth.

METHODOLOGY

Fifty-six mesial roots of mandibular molars, half of them with a continuous isthmus from the cervical to the apical third between the two root canals (type 1), and the other half with a continuous isthmus from the cervical to the middle third and one canal in the apical third (type 2), were included. The root canals were contaminated for 7 days with an Enterococcus faecalis suspension. There were three experimental groups plus a control group (n = 7 per type of root canal anatomy). All the root canals, except for the control group that was not treated, were chemomechanically prepared and then assigned to one of the experimental groups according to the final adjunctive procedure: conventional irrigation, ultrasonic activation or XP-endo Finisher activation. The irrigating solution used was a combination of 2.5% sodium hypochlorite and 9% etidronic acid, and the final protocols were applied for three cycles of 30 s with a 3 mL volume. The antibiofilm activity was evaluated at each location (root canal and isthmus) and third (cervical, middle and apical) using confocal laser scanning microscopy and the live/dead technique. Statistical analysis was performed using SPSS (descriptive statistics) and SUDAAN (P-value calculations).

RESULTS

Root canals had significantly lower biovolume values than the isthmuses (P < 0.05). The biovolume in the root canals was significantly reduced in all the experimental groups in all the thirds except for conventional irrigation in the apical third (P > 0.05). In the cervical and middle thirds, ultrasonic activation was associated with the lowest biovolumes (P < 0.05), followed by XP-endo Finisher. In the isthmus, disinfection was similar in all the thirds for all the protocols. Conventional irrigation was associated with intermediate values with no significant differences from the control group or from the activated protocols (P > 0.05), although the latter were significantly different from the control group (P < 0.05). No differences were found between ultrasonic activation and XP-endo Finisher in the middle and apical thirds (P > 0.05) in the isthmuses.

CONCLUSIONS

In this laboratory study on extracted teeth, the isthmus was more difficult to disinfect than root canals. In the root canals, ultrasonic activation and XP-endo Finisher had a greater effectiveness than conventional irrigation. In the isthmuses, no differences were observed between the two activation techniques and conventional irrigation.

Bibliometric analysis and evaluation of the journal Medicina Oral Patología Oral y Cirugía Bucal (2008-2018)

BACKGROUND

In 2008 the journal Medicina Oral Patología Oral y Cirugía Bucal was included in Journal Citation Reports. To appraise its evolution and current status, this study carried out a bibliometric analysis and evaluation of the journal for the period 2008-2018.

MATERIAL AND METHODS

From the Web of Science, Journal Citation Reports we obtained the indicators Journal Impact Factor (JIF), 5-year JIF, JIF without self-cites, Eigenfactor score and Article Influence score (2010-2017); and from the Core Collection database the following variables: number and article types, institutions and countries of origin of the authors (2008-2018), and the variable cited and citing journal data in 2017. Twelve articles/year (n=132) were randomly selected to gather: the time between submittal and acceptance of an article, number of authors/article, representation of each section, gender of first author, and funding.

RESULTS

The journal occupied the third quartile of the JCR from 2010 to 2017, when it moved up to the second quartile. From 2008 to 2018 it published a total of 1,518 documents, 90% articles and 9.5% reviews. Sixty countries were represented, 48.68% of the documents coming from Spain, and overall 1,293 institutions were involved. Between submittal and acceptance of articles, the average time was 134.42 days, without differences between years. The mean of authors/article was 5.15, increasing over time. The sections most represented were Oral Medicine and Pathology, and Oral Surgery. There were no differences regarding the gender of the first author, and in general the authors did not provide information about funding received.

CONCLUSIONS

The bibliometric results indicate a steadily improving position of this journal, along with a tendency to reduce self-citation. The time between reception of an article and its acceptance was very stable, the number of authors per article showed an increase, and there was a nearly equal representation of males and females as the first author.

Reduction in Enteroccocus faecalis counts - a comparison between rotary and reciprocating systems

AIM

To compare the chemomechanical reduction and regrowth of Enterococcus faecalis between rotary and reciprocating systems in root canal preparation.

METHODOLOGY

Seventy-six single-rooted human mandibular premolars were selected and standardized to 15 mm in length. Root canals were enlarged up to a size 25 K-file and irrigated with distilled water and then were infected with E. faecalis for 4 weeks. The specimens were divided into 3 groups (n = 24) for instrumentation with Mtwo, Twisted File and WaveOne. Each group was further divided into two subgroups (n = 12) according to the irrigant used: distilled water or 5.25% sodium hypochlorite (NaOCl). Before and after rotary preparation, microbiological samples were collected using three sterilized paper points, and efficacy was expressed as reduction in percentage. The proportion of grown samples for 60 days was evaluated using nonparametric Kaplan-Meier survival analysis. Differences amongst groups were tested using the log-rank test at a significance level of 0.05.

RESULTS

In the main root canal, the percentage reduction in the distilled water and 5.25% NaOCl groups ranged from 95.9% to 100%, with no significant differences amongst the three systems (P > 0.05). The bacterial regrowth in NaOCl groups revealed that Mtwo had the lowest number of samples regrown at 60 days, giving statistically significant differences with respect to Twisted File (P = 0.029) and WaveOne (P = 0.005).

CONCLUSIONS

Reciprocating and rotary systems resulted in similar percentage reduction in E. faecalis when using either distilled water or 5.25% NaOCl solution. Over time, the Mtwo system was more effective regarding disinfection.

Sealant and fluoride varnish in caries: a randomized trial

Little is known about the effect of discontinuation of sealant or fluoride varnish. The purpose of this study was to compare sealant with fluoride varnish in the prevention of occlusal caries in permanent first molars of children over a nine-year period: 4 yrs for program evaluation plus 5 yrs of discontinuation. A clinical trial was conducted on three groups of six- to eight-year-old schoolchildren: a control group (n = 45); a group (n = 37) in which sealant was applied and reapplied up to 36 mos; and a group (n = 38) in which fluoride varnish was applied and re-applied up to 42 mos. Percent caries reduction was studied in these initially healthy molars with complete occlusal eruption: 129 (control), 113 (sealant), and 129 (varnish) molars met inclusion criteria. Of these, 76.7%, 26.6%, and 55.8% had developed occlusal caries at 9 yrs, which implies caries reductions of 65.4% (SE = 8.5%) for sealants vs. control and 27.3% (SE = 10.2%) for varnish vs. control. Furthermore, the varnish program was not effective during the discontinuation period.

Mutans streptococci and lactobacilli in saliva after the application of fissure sealants

Because dental fissures may serve as reservoirs for mutans streptococci, preventive measures should be taken to control microbial concentrations at these sites. This study estimated the influence that sealing permanent first molars would have on the levels of mutans streptococci and lactobacilli in saliva of healthy seven-year-old schoolchildren. Permanent first molars were sealed in 31 children without caries (NC group) and in 32 children with caries (C group). None of the children had caries in their permanent first molars. Conventional methods were used to count mutans streptococci and lactobacilli in saliva before applying the sealant and again at 4 and 12 weeks after application. Baseline counts of lactobacilli and mutans streptococci were significantly higher in the C group. A significant reduction in mutans streptococci was observed in the NC group at 4 and 12 weeks. It was concluded that fissure sealants in permanent first molars can help reduce salivary levels of mutans streptococci in children without caries.

In vitro antibacterial activity of glass-ionomer cements

The in vitro antibacterial activity of the glass-ionomer restorative cements Ketac-Cem, Ketac-Bond, Ketac-Silver and Vitrebond was studied in conjunction with 32 strains of five bacteria involved in the development of caries: Streptococcus spp., Lactobacillus spp., Actinomyces spp., Porphyromonas spp. and Clostridium spp. The agar plate diffusion method was used for the cultures, which included a chlorhexidine positive control. All the glass-ionomer cements tested inhibited bacterial growth, but with considerable differences in the scope of their action. Of the four cements, Vitrebond, a resin-modified glass-ionomer cement, was determined to be the most effective bacterial inhibitor.

Antibacterial activity of glass-ionomer restorative cements exposed to cavity-producing microorganisms

The antibacterial activity of the glass-ionomer restorative cements Ketac-Fil, Ketac-Silver, Fuji II LC, and Vitremer was studied in vitro, in conjunction with a total of 32 strains of five bacterial genera that may be associated with dental caries: Streptococcus spp, Lactobacillus spp, Actinomyces spp, Porphyromonas spp, and Clostridium spp. Agar plate diffusion was the method used for the bacterial cultures, which included a chlorhexidine control. All four glass-ionomer cements were found to inhibit bacterial growth, though with noteworthy differences in their spheres of action. Vitremer was the cement determined to have the greatest antibacterial effects, whereas Ketac-Silver presented the least inhibitory action.

A 24-month study comparing sealant and fluoride varnish in caries reduction on different permanent first molar surfaces

OBJECTIVE

The aim of this study was to determine the separate effects of dental sealants and fluoride varnish on dental caries in fissured and nonfissured surfaces of permanent first molars.

METHODS

A clinical trial was conducted with three groups of 6- to 8-year-old schoolchildren: a sealant group (n = 100), in which Delton was applied to first molars; a varnish group (n = 98), in which Duraphat was applied to first molars; and a control group (n = 116), which had no intervention as part of the study. Absolute and percent caries reductions were compared at 24 months.

RESULTS

Compared to the controls, sealants resulted in a 68 percent and 87 percent reduction on fissured and nonfissured surfaces, respectively. The corresponding figures for varnish were 38 percent and 66 percent.

CONCLUSION

Sealant and fluoride varnish are effective in preventing caries in both fissured and nonfissured surface.

A 48-month survival analysis comparing sealant (Delton) with fluoride varnish (Duraphat) in 6- to 8-year-old children

The objective of this study was to compare Delton visible-light fissure sealant with Duraphat fluoride varnish in the prevention of occlusal caries in permanent first molars. A 48-month clinical trial was carried out in three groups of 6- to 8-year-old schoolchildren: a sealant group (104 children), in which Delton was used; a varnish group (112 children), in which Duraphat was used; and a control group (128 children). Sealant or varnish was applied to all sound permanent first molars, according to group. Replacement (sealant) and reapplication (varnish) was carried out every 6 months. A survival analysis was used to describe the molar failures over time in the three groups. A Cox proportional hazards regression model was built to test the influence of group on molar failure. The median survival times were 28.6 months for the control molars and more than 48 months for both sealed and varnished molars. The Cox model indicated a hazard ratio of 0.177 for the sealant vs control comparison, 0.463 for varnish vs control and 0.382 for sealant vs varnish.

Effectiveness of visible light fissure sealant (Delton) versus fluoride varnish (Duraphat): 24-month clinical trial

The present study compares visible-light Delton with Duraphat fluoride varnish for the prevention of occlusal caries in permanent first molars. A clinical trial was carried out in three groups of 6-8-yr-old schoolchildren: a sealant group (100 children), in which Delton light-polymerized fissure sealant was applied to permanent first molars; a varnish group (98 children), in which Duraphat was applied to permanent first molars; and a control group (116 children). Replacement (sealant) and reapplication (varnish) was carried out every 6 months. Percent effectiveness at 24 months (percentage of saving from caries taking molars as analysis unit) for those molars initially healthy and with complete occlusal eruption was analyzed. 272, 252 and 238 molars met the inclusion criteria in the control, varnish and sealant groups, respectively. Of these, 45.2%, 28.2% and 10.5% developed caries after 24 months. The effectiveness was greater in the sealed molars than in the varnished molars (62.7%).

The influence of dft index on sealant success: a 48-month survival analysis

Early loss of pit and fissure sealants is considered to be primarily dependent on inadequate isolation of the tooth from salivary contamination during application. Gradual additional loss is considered to be caused by occlusal wear, shearing forces, and marginal failure. Our hypothesis is that the caries risk of the child may be an additional factor in sealant loss. The objective of this study was to analyze the influence of caries history in primary teeth (dft index) on the success of sealants. Delton light-polymerized sealant was applied in 104 six- to eight-year-old children, followed for four years on a six-month-visit basis. All sound permanent first molars were sealed during the study. A survival analysis was used to describe sealant success over time. A Cox proportional hazards regression model was built to test the influence on sealant success of the dft index and site of sealant application (mandibular occlusal surface, maxillary fossae, and maxillary distolingual fissure), controlling for some potential confounders. Sealant half-life was 46 months. Site and dft index were related to sealant survival. The maxillary fossae showed the best retention, followed by the mandibular occlusal site and the maxillary disto-lingual fissure. The higher the dft, the higher the risk of sealant failure. This study has implications for sealant study designs and public sealant programs.

Factors influencing the effectiveness of sealants--a meta-analysis

Meta-analysis of published studies was applied to analyze the effectiveness of fissure sealants in preventing dental caries. Studies were identified by a MEDLINE search, supplemented by a hand search of the references in the articles recovered. All articles were assessed on the basis of quality, and were combined with the Mantel-Haenszel method. The prevented fraction in the exposed population (PF) was estimated using pooled relative risk. Heterogeneity of the effect and publication bias were also analyzed. Twenty-four studies were included in the meta-analysis. The overall effectiveness of autopolymerized fissure sealants was 71.36% (95% confidence interval 69.69-72.94%). Effectiveness in preventing caries decreased with time, and increased when drinking water was fluoridated (82.69% vs 72.28%). Heterogeneity was significant in most cases, and was further studied with multiple linear regression analysis. It is concluded that autopolymerizing sealants should be used. More research is needed to compare the effectiveness of dental hygienists and dentists in applying sealants.

Phagocytosis and adhesiveness of peripheral blood polymorphonuclear leukocytes in patients with rapidly progressive periodontitis

Phagocytosis and adhesiveness of peripheral blood polymorphonuclear leukocytes were studied in patients diagnosed with generalized rapidly progressive (form A) periodontitis. All patients belonged to a single family and were first degree relatives. In the patients' leukocytes there was a statistically significant reduction in phagocytic index and adhesiveness, in comparison with leukocytes from controls. However, adhesiveness approached control values in the presence of autologous serum, thus implying that serologic factors may enhance this function in patients with this type of periodontitis.

Antimicrobial susceptibility of 1042 strains of Streptococcus mutans and Streptococcus sobrinus: comparison from 1985 to 1989

A total of 1042 strains of Streptococcus mutans and Streptococcus sobrinus isolated between 1985 and 1989 were tested to study the evolution of their sensitivity to penicillin, amoxycillin, amoxycillin/clavulanic acid, cefuroxime, tetracycline, erythromycin, spiramycin, acetyl spiramycin, lincomycin and clindamycin. The strains were taken from stock cultures and isolated from human saliva and dental plaque. The minimal inhibitory concentration (MIC) was determined by an agar dilution method. Except for spiramycin and acetyl spiramycin, all the antibiotics inhibited 100% of the strains with concentrations less than or equal to 2 micrograms/ml. Microorganisms from both species underwent a slow progressive loss of sensitivity to all the antibiotics over a 5-year period of study, showing statistically significant results in most cases.

Epidemiological application of a new bacteriocin typing scheme for Streptococcus mutans

We propose a new bacteriocin typing scheme for Streptococcus mutans (Biotype I) using nine producer strains and a numerical code with three figures. Its application in 75 unrelated S. mutans strains allowed us to type all microorganisms and to obtain a total of 15 bacteriocin types. Its epidemiological use in two family groups allowed us to obtain two bacteriocin types in each one and to show the type relations between the different family components.

[Evaluation of in vitro adhesion of cariogenic microorganisms to enamel and dental filling materials]

The adhesive ability of Lactobacillus, Streptococcus mutans and Actinomyces viscosus-naeslundii on enamel, amalgam and composite of microparticle and small-particle are studied "in vitro". The selective mediums used for the three micro-organisms are, respectively, Rogosa agar, M.S.B. and C.F.A.T. The lower adherence is showed by bacterias of Lactobacillus genus. S. mutans and A. viscosus-naeslundii show similar adherence properties between them. The greatest adherence was obtained in composites, being S. mutans the bacteria with a greatest level of adherence to the composites of small-particle, and A. viscosus-naeslundii the bacteria with more adherence to the ones of micro-particle. The adherence on amalgam was slightly lower than the adherence on enamel.

Familial pericentric inversion of chromosome 8

Eight children from seven presumably unrelated families were identified independently as having an unbalanced recombinant chromosome resulting in the presence of extra material on the short arm of a chromosome 8. Parental chromosomes were analyzed, and one member of each couple (four fathers and three mothers) was found to carry a pericentric inversion of a chromosome 8 [inv(8)(p23q22)]. The propositi had an unbalanced recombinant chromosome [rec(8),dup q,inv(8)(p23q22)]. The affected infants all had developmental delay, congenital heart disease, and unusual appearance. A common origin of the pericentric inversion was suggested because of geographic location and Mexican--American ancestry of the seven families.