Inhibition of cultivable bacteria by chlorhexidine treatment of dentin lesions treated with the ART technique

Effect of Malachite green, Ocimum Sanctum, and Er, Cr: YSGG laser on antimicrobial activity against S.mutans and CAD disinfection bonded to resin restoration

AIMS

Evaluation of survival of S.mutans and shear bond strength (SBS) of adhesive restorative material bonded to carious affected dentin (CAD) after using cavity disinfectant i.e., Er, Cr: YSGG (ECYL), (Nd: YAG) (NYL), Malachite green (MG), Ocimum sanctum (OS) in comparison to the conventional control chlorhexidine gluconate (CHX).

MATERIALS AND METHODS

Seventy-five caries-affected mandibular third molars having ICDAS scores 4 and 5 were included. Carious infected dentin was eliminated and CAD surface was obtained. On twenty-five samples, an uncontaminated suspension of S. mutans strain ATCC 35668 in Brain-Heart Infusion broth (BHI) was obtained after 12 hours of incubation at 37°C. Based on the disinfection regime used to sterilize the CAD surface, all the specimens were allocated into five different groups. (n=15) Group 1: CAD disinfected with CHX, Group 2: CAD disinfected with ECYL, Group 3: CAD disinfected with NYL, Group 4: CAD disinfected with MG, and Group 5: CAD disinfected with OS. An assessment of the survival rate of S. mutans was performed. Fifty specimens were smeared with single-step adhesive bond followed by restoring the CAD surface using packable composite. SBS and failure mode were determined using a universal testing machine and stereomicroscope at 40x magnification. ANOVA and post-hoc Tukey-Kramer test was used for data analysis p=0.05 RESULTS: Group 1: CHX-treated specimens displayed the lowest bacterial viability (0.11±0.03 CFU/mL). However, group 4: MG exhibited the highest bacterial survival (0.15 ±0.09 CFU/mL). The highest and lowest SBS of resin adhesive bonded to disinfected CAD surface were exhibited by (group 5: OS) (21.48±1.39 MPa) and (group 3: NYL) (16.41±0.90 MPa) respectively (p>0.05).

CONCLUSION

Ocimum sanctum seems to be promising in terms of its antibacterial efficacy against S.mutans and positive impact on SBS of resin adhesive to CAD surface.

Adhesive bond of Bioactive and bulk fill resin to disinfected caries affected dentin (lactobacillus specie) with laser and photodynamic therapy

AIMS

To evaluate the antimicrobial effectiveness of cavity disinfectants chlorhexidine gluconate (CHX), Er, Cr, YSGG laser (ECL), and curcumin photosensitizer (CP) against Lactobacillus and shear bond strength (SBS) of Bioactive (BA) and bulk fill composite (BFC) restorative material bonded to carious affected dentin (CAD).

MATERIALS AND METHODS

Sixty human mandibular molars scored 4 and 5 on the International Caries Detection and Assessment System (ICDAS) were included. After inoculating the specimens with lactobacillus specie all the samples were arbitrarily divided into three groups based on the disinfection regime used (n=20). Groups 1 and 2: CAD disinfection using ECL, Groups 3 and 4: CAD disinfection using CP, and Groups 5 and 6: CAD disinfection using CHX. After cavity sterilization, the survival rate was estimated and each group was further divided into two sub-groups based on the restorative material used. Groups 1, 3, and 5 (n = 10) were restored using BFC restorative material, and groups 2, 4, and 6 (n = 10) were restored using a conventional bulk-fill resin material. A universal testing machine (UTM) was used to determine the SBS and debonded surfaces were examined under a stereomicroscope to determine the modes of failure. Kruskal-Walis, ANOVA, and Post Hoc Tukey were applied to investigate the survival rate and bond strength values.

RESULTS

ECL group displayed the highest survival rate (0.73±0.13) of Lactobacillus. The least survival rate (0.17±0.09) was demonstrated by CP activated by PDT. Group 1 (ECL+ BA) treated specimens exhibited the maximum value of SBS (18.31 ± 0.22 MPa). However, group 3 (CP + BA) revealed the minimum values of bond strength (14.05 ± 1.02 MPa). The intergroup comparison revealed that group 1, group 2 (ECL+BFC) (18.11 ± 0.14 MPa), group 5 (CHX+ BA) (18.14 ± 0.36 MPa), and group 6 (CHX+BFC) (18.18 ± 0.35 MPa) displayed comparable outcomes of bond integrity (p>0.05).

CONCLUSION

Caries-affected dentin disinfected with Er, Cr: YSGG, and chlorhexidine improve bond scores of bioactive and conventional bulk-fill restorative material.

Assessment of Salivary Mutans Streptococci Counts to Atraumatic Restorative Treatment Among Children: A Randomised Controlled Trial

Introduction Besides the survival rate of restorations, the effect of atraumatic restorative treatment (ART) on bacterial count is also important. After ART restoration, the bacterial count drops due to the fluoride's antibacterial activity and hence it can decrease the chances of further decay. The present study assessed salivary mutans streptococci counts for six months of evaluations subsequent to ART among 12-15-year-old children attending schools in Piparia village, Vadodara district. Methods ART was performed on 32 children and followed up after six months to evaluate the success rate of ART. Saliva collection and microbial analysis were performed five times from every participant, before ART restoration placement, seven days, 30 days (one month), 90 days (three months) and 180 days (six months) post-restoration. Results At baseline, the mean colony forming units (CFU) was 48.30 ± 46.58, which reduced to 32.64 ± 30.40 at one week, which showed a 32% reduction in colony counts. This further reduced to 18.60 ± 20.81 at one month, marking a further 43% reduction in colony counts. This again reduced to 13.63 ± 18.04 at three months, which showed a 27% reduction in colony counts. CFU came to 16.23 ± 23.34 at six months, which showed a 19% increase in colony counts. Comparison of baseline mean CFU (48.30 ± 46.58) to six months mean CFU of streptococcus mutans (SM) (16.23 ± 23.34) showed a 66% reduction in colony counts. A statistically significant difference was found between numerous intervals of time of CFU of streptococcus mutans. Conclusion The findings reveal that ART is a clinical treatment that can be used to treat caries in young children, and it helped significantly reduce Streptococcus Mutans levels in saliva.

The Effect of Aloe vera and Chlorhexidine as Disinfectants on the Success of Selective Caries Removal Technique: A Randomized Controlled Trial

This study aimed to evaluate the effect of Aloe vera and chlorhexidine "CHX" as disinfectants on the success of selective caries removal technique in deep carious lesions. A total of 60 patients with: (I) deep class II carious lesion diagnosed with reversible pulpitis; (II) good oral hygiene; (III) no gingival recession or periodontal diseases; (IV) no antibiotic or antifungal treatment in the last three months; and (V) no systematic disease or pregnancy were included in the study. Sixty patients were distributed randomly to three experimental groups (n = 20): Group 1: no disinfectant solution was applied (control group); group 2: the cavity was filled with 2% CHX for 5 mins and then dried with a sterilized cotton pellet; group 3: the cavity was filled with Aloe vera extract for 5 mins and then dried with sterilized cotton pellet. One week later, only teeth with vital pulp characteristics were restored definitely with resin composite. After 18 months, clinical and radiographic examination was performed by using a blinded separated evaluator. The data were tabulated and analyzed using the chi-square test by SPSS 13.0 with a significance level (p ≤ 0.05). It was observed that 13 teeth of the control group, 14 teeth of the CHX group, and 16 teeth of the Aloe vera group were diagnosed with healthy vital pulp after 18 months. There was no significant difference between the CHX and the control group; however, there was a significant difference between the Aloe vera and control group (p ≤ 0.007). Aloe vera extract as a cavity disinfectant increases the success rate of selective caries removal technique of deep carious lesions.

Chlorhexidine gluconate enhances the remineralization effect of high viscosity glass ionomer cement on dentin carious lesions in vitro

Background

To compare the mean mineral density (MMD) and examine the remineralization of carious dentin after cavity disinfection with chlorhexidine gluconate (CHX) and restoration with high viscosity glass ionomer cement (H-GIC) in vitro.

Methods

Selective caries removal to leathery dentin was performed in 40 extracted primary molars. The samples were scanned using micro-computed tomography (micro-CT) to determine the MMD baseline and randomly divided into 4 groups (n = 10): Equia™ group, applied dentin conditioner and restored with H-GIC (Equia Forte™), CHX-Equia™ group, disinfected the cavity with 2% CHX before applying dentin conditioner and restored with H-GIC (Equia Forte™), Ketac™ group, restored with H-GIC (Ketac Universal™) and CHX-Ketac™ group, disinfected the cavity with 2% CHX before restored with H-GIC (Ketac Universal™). The samples underwent micro-CT scanning post-restoration and post-pH-cycling to determine their respective MMDs. One sample from each group was randomly selected to analyze by scanning electron microscopy (SEM).

Results

The MMD gain in the 4 groups post-restoration was significantly different between the Equia™ and CHX-Ketac™ groups (oneway ANOVA with Post hoc (Tukey) test, P = 0.045). There was a significant difference in MMD gain post-restoration between the Equia™ and CHX-Equia™ groups (Independent t-test, P = 0.046). However, the Ketac™ and CHX-Ketac™ group’s MMD were similar. The SEM images revealed that the CHX-Ketac™ group had the smallest dentinal tubule orifices and the thickest intertubular dentin among the groups. However, the CHX-Equia™ group had thicker intertubular dentin than the Equia™ group.

Conclusion

Applying 2% CHX on demineralized dentin enhances the remineralization of the dentin beneath the restoration.

Treatment of symptomatic, deep, almost cariously exposed lesions using ozone

The aim of this controlled randomized crossover study was to assess post-treatment pain and the need for root canal treatment after the use of a traditional caries removal method followed by restoration, or after an ozone method of more conservatively managing the deep caries and a restoration. 84 participants (42 males and 42 females, mean age ± SD = 23.9 ± 2.0 years) were randomly allocated to receive either a traditional (n = 42, 21 males and 21 females) or ozone (n = 42, 21 males and 21 females) method. The ozone method only differed from the traditional method by leaving the deep leathery caries on the pulpal floor and then treating this with 20 s of ozone from the healozone X4 (Curozone, Germany). All caries was removed in the traditional group. A conventional glass ionomer cement (Riva Self Cure High Viscosity, SDI, Australia) was placed followed by a bonded composite resin restoration (Filtek Z250 Universal Restorative, 3 M ESPE, USA) in each cavity. The visual analogue scale was used to assess pain scores before treatment and after 24 h. The participants were then followed up for 2 years to assess the need for root canal treatment. Statistical significance levels were set at α ≤ .05. Both groups were associated with significant reduction of pain scores 24 h after treatment (p < .0001). The ozone treatment was associated with less pain 24 h after treatment (p < .0001) and less need for root canal treatment (p = .014), after 2 years follow up, than the conventional treatment. In conclusion, treatment of symptomatic, deep carious lesions by ozone following partial removal of caries was accompanied with less pain and occurrence of RCT after treatment compared to traditional complete caries removal.

Microbiological and SEM assessment of atraumatic restorative treatment in adult dentition

OBJECTIVES

To investigate the practicability of atraumatic restorative treatment (ART) in adults in terms of marginal adaptation of restorations and microbiological changes in residual carious dentin.

MATERIALS AND METHODS

The occlusal dentin caries of 25 permanent molar teeth were removed with hand instruments. The total counts of bacteria (TCB) and the facultative anaerobic bacteria (FAB), mutans streptococci (MS), and Lactobacillus spp. (LB) counts in the affected dentin were evaluated quantitatively. The weights of the samples were measured with an electronic balance (Shimadzu, Type AX200, Japan). The cavities were restored with glass ionomer cement (Ketac^TM Molar Easymix, ESPE Dental AG, Seefeld, Germany). Twenty replicas of randomly selected ART restorations were prepared and marginal adaptation was evaluated by scanning electron microscopy (SEM). After 6 months, the same protocols were repeated. Data were analyzed with paired sample t-tests, Wilcoxon t-tests, Pearson and Spearman correlations, and chi-square tests (p<0.05).

RESULTS

In the sixth month, restoration loss and pulpitis were not observed. The mean weight of samples removed from the cavity floor was less than the baseline (0.014±0.009 and 0.023±0.013 g, respectively) (p<0.01), and the counts of total bacteria, FAB, MS, and LB significantly decreased compared to baseline (p<0.01). The frequency of marginal gaps was increased (p< 0.01).

CONCLUSIONS

ART showed that the counts of microorganisms decreased after 6 months although the marginal gap rates of restorations increased.

CLINICAL RELEVANCE

ART can be a reliable treatment approach in adults for 6 months due to the decrease in microorganism counts, although gaps exist.

The antibacterial efficacy of silver diamine fluoride (SDF) is not modulated by potassium iodide (KI) supplements: A study on in-situ plaque biofilms using viability real-time PCR with propidium monoazide

Silver diamine fluoride (SDF) is commonly used to arrest caries lesions, especially in early childhood caries. Recently, it was suggested that SDF can be combined with potassium iodide (KI) to minimize the discoloration of demineralized dentine associated with SDF application. However, the antibacterial efficacy of SDF alone or combined with KI on in-situ biofilm is unknown. Hence, we compared the anti-plaque biofilm efficacy of two different commercially available SDF solutions, with or without KI, using an in-situ biofilm, analysed using viability real-time PCR with propidium monoazide (PMA). Appliance-borne in-situ biofilm samples (n = 90) were grown for a period of 6 h in five healthy subjects who repeated the experiment on three separate occasions, using a validated, novel, intraoral device. The relative anti-biofilm efficacy of two SDF formulations; 38.0% Topamine (SDFT) and 31.3%, Riva Star (SDFR), KI alone, and KI in combination with SDFR (SDFR+KI) was compared. The experiments were performed by applying an optimized volume of the agents onto the biofilm for 1min, mimicking the standard clinical procedure. Afterwards the viability of the residual biofilm bacteria was quantified using viability real-time PCR with PMA, then the percentage of viable from total bacteria was calculated. Both SDF formulations (SDFT and SDFR) exhibited potent antibacterial activities against the in-situ biofilm; however, there was non-significant difference in their efficacy. KI alone did not demonstrate any antibacterial effect, and there was non-significant difference in the antibacterial efficacy of SDF alone compared to SDF with KI, (SDFT v SDFR/KI). Thus, we conclude that the antibacterial efficacy of SDF against plaque biofilms is not modulated by KI supplements. Viability real-time PCR with PMA was successfully used to analyze the viability of naturally grown oral biofilm; thus, the same method can be used to test the antimicrobial effect of other agents on oral biofilms in future research.

Chlorhexidine to improve the survival of ART restorations: A systematic review and meta-analysis

OBJECTIVES

Our aim was to systematically assess the efficacy of chlorhexidine (CHX) as a cavity pre-treatment or restoration mix-in on the survival of ART restorations.

DATA

We included randomized controlled trials that assessed the effect of cavity pretreatment with CHX or the restoration mix-in of CHX on the survival of ART restorations (test group) versus a similar restorative approach without CHX. Risk of bias was assessed using Cochrane's randomized trial quality assessment Tool (RoB 2.0). Random-effects meta-analysis was conducted, with mean Odds Ratios and 95 % confidence intervals (OR, 95 % CI) as effect estimates. The certainty of the evidence was assessed according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system.

SOURCES

Medline, Web of Science, Cochrane Central were searched. Eligible studies were in- or excluded and data extracted for included studies by two reviewers independently.

STUDY SELECTION

Four studies with 261 patients (mean age 3.8-14.6 years) and 467 ART restorations were included. All studies showed some concerns about the risk of bias. Three studies involving a total of 167 restorations in the CHX group and 188 restorations in the control group, followed up for one year, were submitted to meta-analysis. There were no significant differences between CHX vs. control (OR = 0.79, 95 % CI [0.26, 2.40], P = 0.68, I² = 3%, P = 0.35). The strength of the evidence was estimated as low.

CONCLUSIONS

Based on very limited data, CHX pre-treatment or restoration mix-in did not have any significant benefit for survival of ART restorations.

CLINICAL SIGNIFICANCE

There is a lack of evidence regarding the influence of chlorhexidine on the survival of ART restorations. Our results revealed that there was no significant difference in the survival of ART restorations when CHX was used as a cavity pre-treatment or mix-in.

The effects of cavity disinfection on the nanoleakage of compomer restorations: an in vitro study

Purpose:

Cavity disinfection, in addition to routine caries removal methods, is recommended to eliminate the microorganisms. The aim of this study was to compare the effect of various systems Er,Cr:YSGG lasers, diode lasers and FotoSan and agents Corsodyl; Cervitec and Cervitec Plus and Fluor Protector—on the nanoleakage of compomer restorations when used for cavity disinfection.

Materials and methods:

A total of 40 intact human deciduous molar teeth containing Black V cavities (3×2×1.5 mm) on the buccal and lingual surfaces parallel to the cementoenamel junction were randomly divided into 8 groups according to the cavity disinfection methods. The antibacterial agents and systems were applied according to the manufacturer’s instructions. Restorations were completed using a compomer. The restored teeth were then subjected to thermocycling for 500 cycles in a water bath at 5°C and 55°C with a dwell time of 30 seconds. After the thermocycling procedures, 1-mm sticks were obtained from the center of each cavity to prepare for the nanoleakage test. After the teeth were sectioned, they were immersed in 50 wt % ammoniacal silver nitrate solution for 24 hours and dipped in photo-developing solutions for 8 hours with fluorescent light irradiation. The samples were examined under a scanning electron microscope (SEM). The non-parametric Kruskal-Wallis and Mann-Whitney U test (p<0.05) were applied.

Results:

The Er,Cr:YSGG laser group showed significantly less nanoleakage than all of the tested groups (p<0.01). The diode laser, Fluor protector and FotoSan groups showed similar nanoleakage to that of the control group (p>0.05). The Corsodyl (p<0.01) and Cervitec (p<0.001) groups showed significantly higher nanoleakage than the control group.

Conclusion:

Er,Cr:YSGG laser irradiation which showed lower nanoleakage scores from either control or tested groups can be recommended for cavity disinfection Additionally, a diode laser and FotoSan, which have antibacterial effects and no negative effect on leakage, can be used for cavity disinfection.

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.

In vivo antimicrobial activity of silver diammine fluoride on carious lesions in dentin

Minimally invasive treatment protocols may leave a residual layer of carious dentin, which requires treatment for the inhibition of bacterial growth beneath restorations. We aimed to examine the in vivo effect of silver diammine fluoride (SDF) and SDF + potassium iodide (KI) application on bacteria present in deep carious lesions. We studied the in vivo efficacy in five patients, each of which had five carious lesions. Dentin samples taken before and after treatment were subjected to microbial analyses. Following treatment with SDF, the median colony-forming unit (CFU) counts per mg of dentin reduced from 9 × 10⁵ to 1.6 × 10² (P < 0.05), and following that with SDF + KI, the counts decreased from 2.9 × 10⁵ to 9.2 × 10 (P < 0.05). The use of chlorhexidine gluconate (CHX) reduced CFU counts from 1.1 × 10⁵ to 4.8 × 10² (P < 0.05). In four of the five patients, no CFUs were found on mitis salivarius-bacitracin agar with respect to SDF or SDF + KI application. For CHX, the median CFU count before treatment was 1.6 × 10³ and that after treatment was 1.1 × 10². SDF completely inhibited mutans streptococci growth in four of the five patients, while the growth of anaerobes was not completely inhibited.

Role of Herbal Agents - Tea Tree Oil and Aloe vera as Cavity Disinfectant Adjuncts in Minimally Invasive Dentistry-An In vivo Comparative Study

INTRODUCTION

The prevention and control of caries necessitates the elimination of cariogenic bacteria and cavity disinfectants have proved to play a major role in achieving the goal. The use of phytotherapy is trending and many natural products have shown anti-microbial properties which can be used as cavity disinfectant in the field of dentistry.

AIM

The aim of this study was to compare the efficacy of herbal antibacterial agents (Tea Tree Oil (TTO) and Aloe vera) with commercially available 2% chlorhexidine (CHX) as cavity disinfectant for use in minimally invasive dentistry.

MATERIALS AND METHODS

The study included three test groups, Group I (2% chlorhexidine), Group II (tea tree oil), Group III (Aloe vera gel) with a control group (distilled water). Ten patients with atleast one tooth with an occlusal or occluso-proximal lesion suitable for Atraumatic Restorative Treatment (ART) were selected for each group, dentinal samples were collected using sterile spoon excavators at three stages from each tooth viz., pre-excavation, post-excavation and post-disinfection of the cavities. These dentinal samples were subjected to microbiological analysis for Total Viable Count (TVC). The data collected were statistically analysed using ANOVA and Bonferroni post-hoc test.

RESULTS

The results of present study showed that there was a statistically significant reduction in TVC when compared between pre and post excavation in all the groups (p<0.05) and post- excavation and post-disinfection in all the test groups (p<0.05) (except control group). Post-disinfection, 2% chlorhexidine showed highest reduction in TVC followed by 1% tea tree oil and aloe vera gel.

CONCLUSION

Natural antibacterial agents like tea tree oil and aloe vera could be effectively used as cavity disinfectants which will help in minimizing secondary caries and rendering a long term restorative success.

Effect of the addition of chlorhexidine and miswak extract on the clinical performance and antibacterial properties of conventional glass ionomer: an in vivo study

BACKGROUND

Antibacterial restorations can increase the success rate of minimum invasive dentistry especially in young permanent molars with deep carious lesions as an attempt to preserve maximum dental structure and avoid pulp exposure. Further research is warranted to evaluate different antibacterial agents.

OBJECTIVES

This study aimed to evaluate the efficacy of adding chlorhexidine gluconate (CHX) or aqueous miswak (Salvadora persica) extract on the clinical performance and in vivo antibacterial activity of conventional anhydrous glass ionomer cement (GIC).

DESIGN

The study was a randomized clinical trial. Sixty young permanent molars, with deep carious lesions in 6- to 9-year-old children were included. After randomization, atraumatic restorative treatment (ART) or stepwise excavation was performed followed by bacterial sampling from the center of the remaining carious dentine in the floor of the pulp. GIC powder was mixed with 0.5% chlorhexidine gluconate liquid in group I; with 100% aqueous miswak in group II; and with deionized water in group III (control). Clinical performance for all groups was assessed at 3, 6, and 9 months. After 9 months, restorations were removed and a second bacterial sample was collected for Streptococcus mutans (S. mutans) quantification and analysis by real-time polymerase chain reaction (PCR) test.

RESULTS

Results showed no statistically significant difference in the success rate of the three groups at the 3-month interval. At 6 and 9 months, however, restoration success was 75% then 60% in group I, 100% then 90% in group II, and 95% then 85% in control group. Group II and the control group showed statistically significant higher survival rates than group I. All groups showed reduction in S. mutans counts in underlying dentine, but the percent reduction was significantly higher in group I. (P < 0.001).

CONCLUSIONS

The addition of CHX and miswak to GIC showed superior antibacterial properties than conventional GIC, without seriously affecting the clinical performance of the restoration until the 6-month follow-up, but failure significantly increased in terms of marginal defects at 9 months with CHX (group 1).

Antibacterial capacity of cavity disinfectants against Streptococcus mutans and their effects on shear bond strength of a self-etch adhesive

We evaluated the antibacterial properties of three disinfectants [2% chlorhexidine (CHX), 6% sodium hypochlorite (NaOCl), and 0.01% urushiol)] against Streptococcus mutans and their effects on bond strength of Scotchbond(TM) Universal. The reduction in bacterial growth was evaluated by the colony counting method. Total 105 specimens were assigned to seven groups, according to surface pretreatment: control group (C) without pretreatment; chlorhexidine gluconate with rinse (CR) or without rinse (CD); NaOCl with rinse (NR) or without rinse (ND); and urushiol with rinse (UR) or without rinse (UD). The shear bond test was performed at a cross-head speed of 0.5 mm/min. None of the disinfected specimens had viable microbes after a 30 min incubation. The control group exhibited the strongest bond; however, no significant difference was detected with the disinfectant-treated groups, except weak bonding with ND group. These findings suggest that all disinfectants tested had strong antibacterial capacity and may better be rinsed away.

Effect of disinfecting the cavity with chlorhexidine on the marginal gaps of Cl V giomer restorations

Background

Considering the effect of cavity disinfecting agents on the bonding and sealing ability of restorations bonded to dentin, the aim of this study was to evaluate the effect of chlorhexidine (CHX) disinfecting agent on the marginal gaps of Cl V giomer restorations.

Material and Methods

Cl V cavities were prepared on the buccal surfaces of 60 sound bovine permanent incisors in this in vitro study, with the occlusal and gingival margins in enamel and dentin, respectively. The teeth were randomly divided into two groups (n=30). The teeth in groups 1 and 2 were restored without and with the use of the disinfecting agent in the cavity, respectively, before applying the adhesive. BeautiBond one-step self-etch adhesive and Beautifil II giomer were used to restore the cavities in both groups. After thermocycling and sectioning of the samples, the sizes of marginal gaps at gingival margins were measured in µm under a stereomicroscope. Mann-Whitney U test was used to compare marginal gaps at P<0.05 level of significance.

Results

The means of marginal gaps were significantly different between the two study groups (U=180, P<0.001), with higher means of marginal gaps in group 2 (with CHX disinfection) compared to group 1 (without CHX disinfection) (P<0.0005).

Conclusions

Application of CHX for the disinfection of cavities in giomer restorations resulted in an increase in gingival margin gaps.

Key words:Chlorhexidine, dental marginal adaptation, dental restorations.

In vivo comparison of cavity disinfection efficacy with APF gel, Propolis, Diode Laser, and 2% chlorhexidine in primary teeth

Background:

The survival of atraumatic restorative treatment (ART) restorations would be enhanced if near total elimination of cariogenic microorganisms could be done in the process of cavity cleaning before placing a restoration. Thus, use of disinfecting agents for achieving this goal could herald a new beginning in the field of contemporary dentistry.

Aim:

To assess and compare the cavity disinfection efficacy of APF gel, Brazilian Propolis, Diode Laser, and 2% chlorhexidine (CHX).

Materials and Methods:

The study was a randomized, single blinded, parallel grouped, active controlled trial. Eighty primary molars in 68 children with cavitated dentinal occlusal caries were randomly assigned into four groups (20 teeth each) Group I: APF gel; Group II: Propolis; Group III: Diode Laser, and Group IV: 2% CHX (control). After cavity preparation using ART procedure, dentinal samples collected before and after disinfection with respective agent of the group. These samples were subjected to microbiological evaluation, for total viable count (TVC) on blood agar, Streptococcus mutans on mutans-sanguis (MS) agar, and Lactobacilli (LB) on Rogosa agar.

Results:

Intragroup comparison (Wilcoxon signed rank test) showed significant reductions in TVC, MS, and LB counts in all the groups. Pairwise Mann–Whitney test showed APF gel had least bacterial reductions among the agents tested.

Conclusion:

This study illustrated the need for cavity disinfection. Diode Laser and Brazilian Propolis are equally effective as 2% CHX in cavity disinfection.

Cavity disinfection in minimally invasive dentistry - comparative evaluation of Aloe vera and propolis: A randomized clinical trial

CONTEXT

The survival of atraumatic restorative treatment (ART) restorations would probably increase if near total elimination of cariogenic microorganisms could be done in the process of cavity cleaning before going ahead with the restoration. Thus, use of naturally occurring disinfecting agents for achieving this goal could herald a new beginning in the field of contemporary minimum intervention dentistry.

AIMS

To evaluate the efficacy of hand instruments in excavating dental caries and comparatively evaluate the roles of Aloe vera and propolis as potential cavity disinfecting agents after minimally invasive hand excavation of dental caries.

SETTINGS AND DESIGNS

Experimental, in vivo intergroup split mouth, randomized clinical trial.

SUBJECTS AND METHODS

The study included Group I (Control), Group II (A. vera) and Group III (propolis). Ten patients with three teeth each have occlusal/occlusoproximal lesions suitable for ART were selected. Dentinal samples were collected three times from each tooth viz., preexcavation, postexcavation and postdisinfection of the cavities. These dentinal samples were subjected to microbiological analyses for total viable count.

STATISTICAL ANALYSIS USED

Repeated measures of analysis of variance (ANOVA) with Bonferroni post-hoc test and one-way ANOVA with Tukey post-hoc test.

RESULTS

In all the three groups, significant amount of bacteria were left behind after hand excavation. Group II and Group III, in which cavities were treated with A. vera and propolis extracts respectively, showed a significant reduction in the bacterial counts when compared to control the group.

CONCLUSIONS

Hand excavation alone does not completely eliminate bacteria, which may predispose treated teeth to secondary caries. Both propolis and A. vera extracts can be used as potential natural disinfecting agents, thereby embracing the concept of phytotherapy in minimum intervention dentistry.

Antimicrobial activity of alexidine, chlorhexidine and cetrimide against Streptococcus mutans biofilm

Background

The use of antimicrobial solutions has been recommended to disinfect demineralized dentin prior to placing the filling material. The aim of this study was to evaluate the ability of several antimicrobials in controlling Streptococcus mutans (SM) biofilm formed in dentin.

Methods

Antimicrobial activity of 0.2% and 2% chlorhexidine (CHX), 0.2% cetrimide (CTR) and 0.2%, 0.5%, 1% and 2% alexidine (ALX) was assayed on 1-week SM biofilm formed on standardized coronal dentin blocks. Results of SM biofilm antimicrobial activity by different protocols were expressed as the kill percentage of biofilm and the term “eradication” was used to denote the kill of 100% of the bacterial population. To compare the efficacies of the different protocols the Student t test was used, previously subjecting data to the Anscombe transformation.

Results

All ALX concentrations tested and 0.2% CTR achieved a kill percentage higher than 99%, followed by 2% CHX with percentages above 96% (no statistically significant difference among them). Whereas 2% ALX and 0.2% CTR respectively showed eradication in 10 and 9 of the twelve specimens, 0.2% CHX did not produce eradication in any case.

Conclusions

The present study shows that, when used for one minute, 2% and 1% alexidine, and 0.2% cetrimide, achieve eradication of Streptococcus mutans biofilm in most specimens when applied to a dentin-volumetric model.

Comparing the antibacterial activity of gaseous ozone and chlorhexidine solution on a tooth cavity model

OBJECTIVE

To evaluate the antibacterial activity of gaseous ozone and chlorhexidine solution on a tooth cavity model.

STUDY DESIGN

Twenty-one human molars were divided into 3 groups. Cavities were then cut into the teeth (4 per tooth, 28 cavities per group). After sterilization, the teeth were left in broth cultures of 106 colony-forming units (CFU) ml-1 of Streptococcus mutans (S. mutans) at 36°C for 48 h. The appropriate treatment followed (group A, control; group B, 2% chlorhexidine solution; and group C, 80s of treatment with ozone, and the cavities were then filled with composite resin. After 72h, the restorations were removed, dentin chips were collected with an excavator, and the total number of microorganisms was determined.

RESULTS

Both of the treatments significantly reduced the number of S. mutans present compared with the control group and there was a significant difference between the all groups in terms of the amount of the microorganisms grown (p < 0.05). Group B was beter than group C; and group C was better than group A. Moreover, it was found that the amount of the growth in the group of chlorhexidine was significantly less than that of the ozone group (p < 0.05).

CONCLUSION

Chlorhexidine solution was the antibacterial treatment most efficacious on S. mutans; however, ozone application could be an anlternative cavity disinfection method because of ozone's cavity disinfection activity. Key words:Antibacterial activity, chlorhexidine, ozone, streptococcus mutans, tooth cavity.

Bond strength of self-adhesive resin cements to dentin after antibacterial and chelating solution treatment

OBJECTIVE

The aim of this study was to evaluate the effect of tetracycline HCl, 1-hydroxyethylidene-1, 1-bisphosphonate (HEBP) and chlorhexidine digluconate (CHX) on micro push-out (µ-PO) bond strengths of two self-adhesive resin cements on dentin.

MATERIALS AND METHODS

Sixty discs of 1.25 mm thickness (middle dentin) were prepared from human molars perpendicular to the tooth axis. Two standardized occlusal cavities of 2.20 mm occlusal diameter and 1.25 mm cervical diameter were prepared in each disc. The cavities were divided into three groups in accordance with the surface treatment (50 mg/ml tetracycline HCl, 18% HEBP and 2% CHX solutions). Following the treatment of the discs for 5 min, cavities were filled with two different self-adhesive resin cements (Clearfil(™) SA Cement and RelyX(™) Unicem). After light polymerization of cements, µ-PO bond strength tests were performed. Failure modes were examined and dentin morphologic assessments were done. Statistical significance was determined by a multivariate analysis of variance (MANOVA) followed by Tukey's post-hoc test (p < 0.05). Additionally, a paired-samples T-test was used to compare the µ-PO bond strengths of self-adhesive resin cements (p < 0.05).

RESULTS

Paired-samples T-test revealed that there was no significant difference between tested self-adhesive resin cements (p = 0.612). No significant two-factor interaction was observed between Clearfil(™) SA Cement and chemical agents (p = 0.457). Similarly, tetracycline HCl and CHX did not have a significant effect on the bond strength of RelyX(™) Unicem (p > 0.05). However, HEBP significantly decreased the bond strength of RelyX(™) Unicem when compared to the control (p < 0.05). Conclusion. The tetracycline HCl and CHX solutions do not have beneficial effects on µ-PO bond strengths of self-adhesive resin cements. Additionally, the results of this study do not justify the use of self-adhesive resin cements, following HEBP treatment of dentin.

CLINICAL SIGNIFICANCE

The application of topical HEBP solution treatment to dentin could have adverse effects on the µ-PO bond strengths of RelyX(™) Unicem.

Minimal intervention dentistry for managing dental caries - a review: report of a FDI task group

This publication describes the history of minimal intervention dentistry (MID) for managing dental caries and presents evidence for various carious lesion detection devices, for preventive measures, for restorative and non-restorative therapies as well as for repairing rather than replacing defective restorations. It is a follow-up to the FDI World Dental Federation publication on MID, of 2000. The dental profession currently is faced with an enormous task of how to manage the high burden of consequences of the caries process amongst the world population. If it is to manage carious lesion development and its progression, it should move away from the 'surgical' care approach and fully embrace the MID approach. The chance for MID to be successful is thought to be increased tremendously if dental caries is not considered an infectious but instead a behavioural disease with a bacterial component. Controlling the two main carious lesion development related behaviours, i.e. intake and frequency of fermentable sugars, to not more than five times daily and removing/disturbing dental plaque from all tooth surfaces using an effective fluoridated toothpaste twice daily, are the ingredients for reducing the burden of dental caries in many communities in the world. FDI's policy of reducing the need for restorative therapy by placing an even greater emphasis on caries prevention than is currently done, is therefore, worth pursuing.

Antimicrobial effect of chlorhexidine digluconate in dentin: In vitro and in situ study

Aim:

The aim of this study was to evaluate a very short-term in vitro and in situ effect of 2% chlorhexidine-digluconate-based (CHX) cavity cleanser on the disinfection of dentin demineralized by cariogenic bacteria.

Materials and Methods:

Human dentin slabs were randomly allocated and used in 2 distinct phases, in vitro and in situ, for obtaining demineralized dentin. In vitro, the slabs (n=15) were immersed for 5 days in BHI broth inoculated with Streptococcus mutans CTT 3440. In situ, a double-blind design was conducted in one phase of 14 days, during which 20 volunteers wore palatal devices containing two human dental dentin slabs. On 5^th day in vitro and 14^th day in situ, the slabs were allocated to the two groups: Control group (5 μl of 0.9% NaCl solution) and CHX group (5 μl of 2% chlorhexidine digluconate solution, Cavity Cleanser™ BISCO, Schaumburg, IL, EUA), for 5 minutes. The microbiological analyses were performed immediately before and after the treatments.

Results:

The log reductions means found for CHX treatment on tested micro organisms were higher when compared to Control group either in vitro or in situ conditions.

Conclusions:

Our results showed that CHX was effective in reducing the cultivable microbiota in contaminated dentin. Furthermore, although the use of chlorhexidine-digluconate-based cavity disinfectant did not completely eliminate the viable microorganisms, it served as a suitable agent to disinfect tooth preparations.

Class III atraumatic restorative treatment (ART) in adults living in West Africa--outcomes after 48 months

OBJECTIVES

This observational study assessed the effectiveness of class III restorations using the atraumatic restorative treatment (ART) approach in permanent anterior teeth over a 48-month period.

METHODS

Dental auxiliaries placed a total of 117 class III ART restorations in 2004, using a cosmetically improved glass-ionomer (Ionofil® Plus; VOCO, Cuxhafen, Germany), in 67 patients with a mean age of 27.3 years in the rural Jahali Health Center, The Gambia. Independent examiners evaluated the restorations after 24 and 48 months using the clinical ART evaluation criteria.

RESULTS

Seventy-six of the restorations could be observed over 48 months in 51 patients. After 48 months, 53 of 76 restorations were classified as clinically acceptable (without or with minor intervention (repair) needed), and 23 restorations were classified as insufficient. There was no statistical difference in a clustered performance rating between restorations placed in central and lateral incisors (P=1.0).

CONCLUSIONS

The adoption of the ART approach to class III caries cavities made restorative dental care in anterior teeth available in a West African region. The long-term performance was comparable to other studies. Longitudinal clinical studies with greater populations are required to substantiate these results.

Clinical and microbiological performance of resin-modified glass-ionomer liners after incomplete dentine caries removal

The aims of this study were to evaluate clinically and microbiologically the effects of two resin-modified glass-ionomer cements (RMGICs) used as liners after incomplete dentine caries removal and to identify Streptococcus mutans and Streptococcus sobrinus strains isolated from dentine samples, before and after indirect pulp treatment. Twenty-seven primary molars with deep carious lesions, but without signs and symptoms of irreversible pulpitis, were submitted to indirect pulp treatment. Treatment consisted of incomplete excavation of the carious dentine, application of one of the RMGICs (Vitrebond or Fuji Lining LC) or calcium hydroxide cement (Dycal), and sealing for 3 months. Clinical evaluation (consistency, color, and wetness of dentine) and carious dentine collects were performed before temporary sealing and after the experimental period. Microbiological samples were cultivated in specific media for subsequent counting of mutans streptococci (MS) and lactobacilli (LB). MS colonies were selected for identification of S. mutans and S. sobrinus by polymerase chain reaction. After 3 months, the remaining dentine was hard and dry, and there was a significant decrease in the number of MS and LB, in all groups, although complete elimination was not achieved in 33% and 26% of the teeth for MS and LB, respectively. From 243 MS colonies selected, 216 (88.9%) were identified as S. mutans and only 2 (0.8%) as S. sobrinus. The use of resin-modified glass-ionomer liners after incomplete caries removal, as well as a calcium hydroxide cement, promoted significant reduction of the viable residual cariogenic bacteria in addition to favorable clinical changes in the remaining carious dentine.

Surface antibacterial properties of glass ionomer cements used in atraumatic restorative treatment

BACKGROUND

Atraumatic restorative treatment (ART) is recommended for use worldwide, not only in developing countries where resources are not readily available, but also in more industrialized countries. The antibacterial properties of restorative dental materials may improve the restorative treatment outcome. Glass ionomer cement (GIC) has been advocated as the preferred restoration material for ART. The authors evaluated the antibacterial properties of restorative materials-three GICs and a zinc oxide eugenol (ZOE)-in vitro.

METHODS

Streptococcus mutans, Actinomyces viscosus and Enterococcus faecalis were the test microorganisms. The authors used a quantitative microtiter spectrophotometric assay to evaluate the antibacterial effect of the restorative materials using the direct contact test (DCT) of freshly prepared and one-week-aged materials.

RESULTS

The freshly prepared GICs and ZOE showed no bacterial growth in all tested bacteria compared with a control. This effect lasted for at least one week for S. mutans and A. viscosus but not for E. faecalis.

CONCLUSIONS

Conventional GICs used in ART showed antibacterial surface properties against cariogenic bacteria for at least one week. Further study on the long-term antimicrobial effects of GICs is needed.

CLINICAL IMPLICATIONS

The antimicrobial properties of freshly prepared restorative materials and aged restorative materials used in ART have a potent effect against cariogenic bacteria. These properties have crucial importance in preventing secondary caries.