Protect Bond Research Articles

Profile of MDP-chlorhexidine for universal dentin bonding systems: A calcium-competition interference?

10-methacryloyloxy-decyl-dihydrogen phosphate (10-MDP) mostly changed the bonding concept by chemically interacting with hydroxyapatite. Currently, multimode simplified universal dentin bonding systems (UDBSs) contains 10-MDP, and its use in etch-and rinse mode renewed the concern on the employment of antienzymatic agents as chlorhexidine (CHX). This study aimed to investigate the effect of MDP-CHX interaction on bonding properties. The following DBSs were tested: MP-Adper Scotchbond Multipurpose, SU-Adper Scothbond Universal, CSE-Clearfil SE Bond, and CPB–Clearfill Protect Bond. The degree of conversion (DC) was assessed by a drop of each DBS (≈3.0 μL, n = 3) combined with chlorhexidine diacetate (0, 0.2, and 2%) and hydroxyapatite (HAP) (0, 0.1%) using Fourier Transform Infrared Spectroscopy (FTIR). Bond strength (BS) was tested using 144 human third molars, randomized according to DBS/CHX groups (n = 12), and submitted to the microtensile test (μTBS) at 24-h, 6-month, and 12-month periods. Failure mode of interfaces, FTIR profile, and Scanning Electronic Microscopy (SEM) were assessed. DC and BS data were statistically analyzed by three-way and Repeated Measures ANOVA followed by Tukey tests (p < 0.05). Results: CHX decreased DC values of MDP-based systems, while HAP/CHX recovered DC values compared with control. CHX reduced BS values for CSE (MDP-based), while improved BS values for MP (MDP-free). MDP-based system associated particularly with 2% CHX should be avoided even for multimode simplified DBS, as both ingredients may compete for calcium, reducing their benefits.

Do Underwriters with Foreign Shareholders Help Protect Bond Investors? Evidence from Bond Covenants in China

Do Underwriters with Foreign Shareholders Help Protect Bond Investors? Evidence from Bond Covenants in China

Shear bond strength after using sealant before bonding: a systematic review and meta-analysis of in vitro studies.

Decalcification during orthodontic treatment is significantly increased. To prevent this negative impact, new treatments with sealants before bonding brackets are commonly been used. This systematic review discusses current knowledge on shear bond strength when using sealant before bonding. A systematic review and meta-analysis were performed to identify studies that address shear bond strength after using a sealant before bonding brackets. The search was carried out using common electronic databases in addition to individual searches. Both screening and study eligibility analysis were performed according to PRISMA and Cochrane Guidelines for systematic reviews. Several terms describing shear bond strength after using a sealant before bonding brackets were searched. Particular attention was paid to bond failure and bracket loss. For the statistical outcome, all results were shown in a forest plot based on standardized mean differences (SMD) with a random-effects model to respect heterogeneity of these studies. To assess the heterogeneity of the different trials, I2-value and the Q-Test were performed. The initial search identified 416 studies. After a thorough selection process, a total of 15 articles met the inclusion criteria. All 15 articles reported results of in vitro studies. Papers were divided into four subgroups according to their used product: ProSeal, Transbond bonding, the combination of Transbond bonding and ProSeal and Clearfil Protect Bond. The results of this review demonstrate a high heterogeneity of the studies. The SMD of the examined 15 articles show nearly no difference between the control and the intervention groups in shear bond strength (p < 0.0001; OR - 0.12; Cl - 0.47-0.23). Forest plots for comparison of the subgroups depict no difference in shear bond strength as well. This meta-analysis concludes that there is no additive benefit for shear bond strength when using sealant before bonding. However, additional randomized controlled studies should be performed to analyze impact of sealants on bonding strength and bracket loss in more detail. Using sealants before orthodontic bonding does not reduce shear bond strength.

Antibacterial effect of a brominated self-etch adhesive on carious dentin - An in vivo study

ObjectivesThis in vivo study compared the antibacterial effect of a self-etch adhesive with and without the brominated monomer 12-methacryloyloxydodecyl-pyridinium bromide (MDPB) on carious dentin after selective caries removal. Methods10 patients showing deep primary carious lesions at two posterior teeth without pulpal symptoms were included. At visit I, carious tissue was selectively removed and carious dentin was sampled with a sterile roundbur (Komet No. 18). One cavity was restored with composite (SDR, Ceram X; DENTSPLY DeTrey) using an MDPB-containing self-etch adhesive (Clearfil Protect Bond, Kuraray Noritake; PB). The other restoration served as a control (Clearfil SE Bond II, Kuraray Noritake; SE). At visit II after 8 weeks, carious dentin was sampled again. Bacterial growth in carious dentin was differentiated using microbial cultivation. Bacterial DNA from intact cells and cell-free DNA were quantified using 16S rRNA gene-based real-time PCR and the microbial community composition was analyzed by amplicon deep-sequencing. Wilcoxon test was applied for statistical analysis. ResultsBoth treatments showed a decrease of intact bacterial cells in carious dentin at visit II compared to visit I (PB: visit I: 1.1*106, visit II: 1.7*105 (p = 0.03); SE: visit I: 1.1*107, visit II = 2.4*105 (p = 0.002)). No statistically significant reduction of cell-free bacterial DNA was detected (PB: visit I: 6.1*105, visit II: 1.6*105 (p = 0.08); SE: visit I: 5.3*105, visit II: 2.9*105 (p = 0.10)). The decrease of intact cell-derived (p = 0.371) and cell-free DNA (p = 0.455) did not differ significantly between PB and SE. Lactobacillus was most abundant within the microbial community at both visits. Alpha-diversity was not affected by treatment and samples showed high intra- and interindividual diversity. Conclusion and clinical significanceBoth self-etch adhesives have an antibacterial effect due to a decrease of bacterial DNA after selective caries removal. However, the results do not reveal any additional antibacterial effect by MDPB.The study is registered with the German Clinical Trials Register (DRKS00011532).

Transverse Micro Radiography Analysis of the Effect of Experimental Calcium-Containing Primer System on Demineralized Enamel

Background: Enamel mineral density is dependent on a balanced dynamic process of demineralization and remineralization. Objective: We evaluated the remineralization potential of experimental calcium- containing primer (CaP) application on enamel subsurface lesions. Methods: Demineralized enamel samples obtained from bovine incisor teeth were prepared and cut buccolingually. All samples were divided into 4 main groups according to the type of primer: CLEARFIL SE BOND 2 Primer (SEP), experimental calcium-containing primer (CaP) and bond: CLEARFIL SE BOND 2 Bond (SEB), CLEARFIL Protect Bond (PBB) treatment: (1) SEP-SEB (2) SEP-PBB (3) CaP-SEB (4) CaP-PBB. Each group was subdivided according to storage time in artificial saliva: immediately, 1 month and 6 months. Then, the samples were analyzed using transverse micro radiography (TMR). Additionally, the samples treated with each primer were prepared for scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDS) observation. Two-way ANOVA was used for the statistical analysis of mineral loss (ΔZ: vol%·µm). Results: CaP-PBB had the significantly lowest ΔZ at all storage times, while SEP-SEB had the highest ΔZ (p &lt; 0.05). SEM observations revealed that new crystals were formed on the surface after 6 months, and the ratio of calcium on the enamel increased in the EDS analysis. Conclusion: Experimental calcium-containing primer can provide additional mineral deposition, with even further deposition when combined with a fluoride-containing bond.

Evaluation of Caries-Free Restorations Bonded with Various Adhesive Systems: In Vitro Study.

Purpose Secondary caries originate from a leakage pathway where oral acids can penetrate faster and demineralize the tooth substrate deeper which can be visualized by dye penetration. The ability to prevent secondary caries by contemporary adhesive systems was evaluated in this study. Dye penetration distance through leakage and into the tooth substrate adjacent to Class V restorations after artificial caries exposure was compared. Materials and Methods Previously frozen extracted human molars were used to prepare the Class V cavities at the CEJ on axial surfaces. All cavities were restored with either the resin-composite or amalgam with or without resin adhesives: dry bonding: Super-Bond D-Liner II Plus; moist bonding: All-Bond 2; and self-etch bonding: AQ Bond and Clearfil Protect Bond. Two subgroups of Super-Bond D-Liner II Plus were immersed for 14 days at 37°C either in artificial saliva (negative control) or the artificial caries solution. The other groups were soaked in the artificial caries solution. The distance of dye penetration into the adjacent enamel, cementum/dentin, and tooth-resin interfaces was measured after immersion in 0.5% basic fuchsin dye for 24 h. The tooth-resin interfacial layer was investigated using SEM. Results No dye penetration into the tooth-resin interface was found in Super-Bond D-Liner II Plus and AQ Bond groups which demonstrated a constant hybrid layer after a chemical challenge. The leakage distance at the cementum/dentin-resin interface of All-Bond 2, Clearfil Protect Bond, and non-adhesive amalgam (positive control) groups was significantly higher than the distance of dye penetration into the adjacent demineralized root surface (p < 0.05). Conclusion Caries associated with either amalgam or resin-composite restorations can be prevented using resin adhesives which can penetrate into the intact tooth substrate to form a stable hybrid layer. With caries-free restorations, tooth vitality may be conserved lifelong.

Effectiveness of an antibacterial primer used with adhesive-coated brackets on enamel demineralization around brackets: an in vivo study

BackgroundThe aim of the study is to assess the clinical effect of an antibacterial monomer-containing primer on preventing white spot lesions (WSLs) during fixed orthodontic treatment.Subject and methodsThe study included 35 patients. A split-mouth design was used during bonding of the brackets. In Clearfil (CF) group, adhesive-coated brackets (APC Plus Victory series, 3M Unitek, Monrovia, CA, USA) were bonded with an antibacterial monomer-containing primer (Clearfil Protect Bond, Kuraray Medical, Okayama, Japan). In Transbond (TB) group, the same adhesive-coated brackets were bonded using a conventional primer (Transbond XT Primer; 3M Unitek, Monrovia, CA, USA). The mean duration of orthodontic treatment was 16 months. Digital images of each tooth were used to assess the WSLs. The areas of the WSLs were measured with a software. The bond failures during orthodontic treatment were also recorded.ResultsAfter fixed orthodontic treatment, 23 of the 35 patients showed one or more WSLs. Of the total of 666 teeth, 114 WSLs occurred over the orthodontic treatment time. Rates of WSL in the CF and TB groups were 8.03% and 9.24%, respectively. The difference in WSL rates between the two groups was not statistically significant. No significant difference was observed in the lesion areas between the groups. Moreover, the difference in bracket failure rates between the two groups was also not statistically significant.ConclusionThe results of this long-term clinical study indicated no significant difference between the antibacterial monomer-containing primer group and the control group in the efficacy of reducing demineralization throughout the orthodontic treatment.

Lingual Bracket Systems with Self Etching Primers—An In Vitro Study to Evaluate Shear Bond Strength

To evaluate the shear bond strength of orthodontic lingual bracket systems bonded to extracted premolar teeth (Reliance self-etching primer, Clearfil Protect Bond) and self-etching primer (Clearfil SE Bond) Materials and methods: A total of 160 extracted human first premolars were selected and divided into four groups of 10 for each bracket system to be used with four different primers. Each sample was then embedded in an acrylic block, till the coronal portion. Instron testing machine model LR LOYD 50 K was used for testing the shear bond strength. The results obtained, suggested that all the primers had clinically acceptable shear bond strength with all the bracket system considered in the study. However, there were statistically significant differences in the shear bond strength in intergroup comparisons. The Reliance Self-Etching primer showed the highest bond strength with Alias lingual bracket system by Ormco, followed by clearfil protect bond, clearfil SE bond, and transbond, with the Alias lingual bracket system in the same order. This study was initiated to understand the shear bond strength of self-etching primer and its efficacy over the conventional primer, which will be of use to the clinician while selecting the primer for bonding of the bracket systems and overcome debonding of brackets encountered during the treatment progress.

Antibacterial Effect of Surface Pretreatment Techniques against Streptococcus Mutans.

The aim of this study was to evaluate the antibacterial surface pretreatment methods against Streptococcus mutans within the infected dentin surface using a tooth cavity model. Seventy-two cavities were prepared on caries-free third molars (n = 8). After sterilization, teeth were inoculated with S. mutans for 48 h. One cavity of each tooth was used to evaluate the infection. Following inoculation, infected cavity surfaces were treated either with (1) Er:YAG Laser (1W; 5x5s, Smart 2940D Plus, Deka Laser), (2) Ozone (80s; HealOzone, Kavo), (3) ErYAG-Ozone combination, (4) Er:YAG-Ozone-CHX combination, (5) Chlorhexidine (CHX), (6) Clearfil Protect Bond (PB), (7) potassium-titanyl-phosphate (KTP) Laser (1W; 60 s, SMARTLITE D, Deka Laser), (8) KTP-Ozone combination, and (9) KTP-Ozone-CHX. Standardized amounts of dentin chips were obtained from the cavity walls, and the number of bacteria recovered was counted. Kruskal-Wallis test was used for statistical analyzes. Both sole antibacterial materials, CHX or Protect Bond application, exhibited the most effective antibacterial activity with 125 and 156 CFU is an acronym of "colony forming unit" usullay mentioned by acronym. (CFU/ml), respectively, among the groups evaluated (P < 0.05). Er:YAG laser irradiation and its combinations with other antibacterial surface pretreatment applications also inhibited the bacterial growth with, respectively, 1444, 406, and 294 CFU/ml bacterial recovery being more efficient than KTP laser irradiation and ozone combinations. As an alternative device with photodynamic effects, Er:YAG and KTP laser irradiations and their further combinations during the cavity pretreatment procedure with chlorhexidine and ozone treatments exerted antibacterial effect against S. mutans, whereas chlorhexidine and antibacterial dentin bonding application solely have the highest antibacterial effects.

Antibacterial Effect and Tensile Bond Strength of Self-etching Adhesive Resins with and without Methacryloyloxydodecylpyridinium Bromide: Anin vitroStudy

Aim: The aim of the present study was to compare the antibacterial activity of a self-etching primer containing antibacterial monomer methacryloyloxydodecylpyridinium bromide (MDPB) (Clearfil protect bond) with a conventional self-etching primer without MDPB (Clearfil SE bond) against Streptococcus mutans and the effect of incorporation of MDPB on the tensile bond strength of the experimental self-etching primer (Clearfil protect bond). Materials and methods: The antibacterial activity of the self-etching primers was assessed using agar disk diffusion method and the diameters of the zones of inhibition were measured and ranked. For tensile bond strength testing, 20 noncarious human molars were selected and randomly divided into two groups comprising 10 teeth in each group. Group I specimens were treated with Clearfil SE bond (without MDPB). Group II specimens were treated with Clearfil protect bond (with MDPB). Composite material was placed incrementally and cured for 40 seconds in all the specimens. Tensile bond strength was estimated using the Instron Universal testing machine at a crosshead speed of 1 mm/min. Results: The addition of MDPB into a self-etching primer exerts potential antibacterial effect against S. mutans. The tensile bond strength of MDPB containing self-etching primer was slightly lower than that of the conventional self-etching Clearfil protect bond primer, but the difference was not statistically significant. Conclusion: Thus, a self-etching primer containing MDPB will be a boon to adhesive dentistry as it has bactericidal property with adequate tensile bond strength. Clinical significance: The concept of prevention of extension in adhesive dentistry would result in micro/nanoleakage due to the presence of residual bacteria in the cavity. Self-etching primers with MDPB would improve the longevity of such restorations by providing adequate antibacterial activity without compromising the bond strength. Keywords: Antibacterial property, Methacryloyloxydodecy-lpyridinium bromide, Self-etching primers, Tensile bond strength.

Immediate and 6-month Bond Strengths of Different Adhesives in the Oral Environment.

To evaluate the microtensile bond strength (μTBS) of three adhesives to dentin after 1 week and 6 months in an oral environment. Class I cavities were prepared in the third molars of 30 patients and randomized into 3 groups according to the following adhesives: Scotchbond Multi-Purpose (SM), Clearfil Protect Bond (CF), and Scotchbond Universal (UN). These molars were then subdivided into two groups according to the exposure time in the oral environment: one week (1W) and 6 months (6M). After the exposure time, the teeth were extracted, cut into beams, and submitted to the μTBS test. The data were analyzed using the Shapiro-Wilk test and two-way ANOVA followed by Tukey's post-hoc test with a significance level of 5%, and fracture modes were analyzed. The bond strengths in MPa (mean ± SD) were SM-1W: 39.5 ± 7.9; SM-6M: 29.7 ± 1.8; CF-1W: 30.5 ± 1.4; CF-6M: 28.6 ± 4.1; UN-1W: 30.6 ± 3.2; and UN-6M: 26.7 ± 2.0. The SM-1W group exhibited significantly increased μTBS compared with the other groups. After 6 months in the oral environment, a significant reduction of μTBS was only observed for the SM group, whereas similar bond strengths were observed for the other groups. SM-1W exhibited a predominance of mixed fractures, whereas the other groups showed a predominance of adhesive fractures. The adhesives which were applied in the self-etching mode maintained bond strength after six months in the oral environment. A reduction of μTBS was only observed for the three-step etch-and-rinse adhesive.

The effects of self-etch bio-active dental adhesive systems on bacterial microleakage

The aim of this in vitro study was to evaluate the effects of bio-active and non-bio-active self-etch adhesive sytems on bacterial microleakage of class II box cavities with restoration margins in dentin. Two bio-active (Clearfil Protect Bond and F1 Bond II) and two nonbio-active (Clearfil SE Bond and Clearfil s3 Bond) adhesive systems were selected for the study. Eighty mesial and distal class II box cavities were prepared on fourty sound human third molar teeth. The teeth were then divided into four groups with 10 teeth in each group. Groups were restorated using different adhesive systems. The restored specimens were immersed into a culture medium containing streptococcus mutans for bacterial microleakage test. Serial sections of the specimens were used to evaluate the bacterial lekage by using light microscope. The data obtained from the test of bacterial microleakage was evaluated using 2-way mixed analysis of variance (p < 0.05). Statistical analysis showed significant differences between the groups (p < 0.05). Nevertheless it was observed that none of the tested adhesive systems including the bio-active ones were successfull in eliminating bacterial microleakage.

In vivo effect of antibacterial and fluoride-releasing adhesives on enamel demineralization around brackets: A micro-CT study

The aim of this in vivo study was to investigate the preventive effect of two different adhesives on enamel demineralization and compare these adhesives with a conventional one. Fifteen patients requiring the extraction of their first four premolars for orthodontic treatment were included in the study. One premolar was randomly selected, and an antibacterial monomer-containing and fluoride-releasing adhesive (Clearfil Protect Bond, Kuraray Medical, Okayama, Japan) was used for orthodontic bracket bonding. Another premolar was randomly selected, and a fluoride-releasing and recharging orthodontic adhesive (Opal Seal, Ultradent Products, South Jordan, Utah) was used. One premolar was assigned as a control, and a conventional adhesive (Transbond XT, 3M Unitek, Monrovia, Calif) was used. The teeth were extracted after 8 weeks, and the demineralization areas of the 45 extracted teeth were analyzed using microcomputed tomography with software. There was no significant difference between the white spot lesion (WSL) rates of the adhesives (P > .05). The volumes of the WSLs varied from 0 to 0.019349 mm3. Although Opal Seal showed the smallest lesion volumes, there was no significant difference in volumetric measurements of the lesions among the groups (P > .05). The findings indicated no significant differences between the preventive effects of the adhesives used in this in vivo study over 8 weeks.

Effect of antibacterial/adhesive approaches on bonding durability of fiber posts cemented with self-etch resin cement.

BackgroundLongevity of post-retained restoration is highly depended on bonding stability of fiber post (FP) to root dentin. This study evaluated the effect of different antibacterial/adhesive approaches on bonding durability of FPs luted into root canal with a self-etch cement.Material and MethodsSeventy-two human maxillary central incisor roots were divided into six groups after endodontic treatment, based on the antibacterial/adhesive treatments as follows: 1)ED primer II (ED, control); 2) Clearfil Protect Bond (PB); 3) 2% chlorhexidine (CH) pretreatment + ED primer II (CH+ED); 4) CH-incorporated into ED primer II (CH in ED); 5) CH pretreatment + Clearfil SE Bond (CH+SE); and 6)CH-incorporated into SE primer (CH in SE). The FPs were then cemented using PanaviaF2.0. After micro-slicing the bonded root dentin, a push-out bond strength (PBS) test was performed immediately or after two years of water storage. Data were analyzed using ANOVA and post hoc Tukey tests (α=0.05).ResultsThe effects of antibacterial/adhesive approach, time and interaction between the main factors were significant (p=0.01). There was no significant difference between the immediate groups, except between the CH+ED group (the lowest PBS) and PB and CH in SE groups (the highest PBS) (p≤0.03). After aging, the same difference was observed (p≤0.02); the control group exhibited a significantly lower PBS compared to the other groups (p≤0.01), except for CH+ED. Aging significantly decreased PBS of all the groups (p≤0.01); the control group exhibited the highest reduction.ConclusionsCH incorporated into self-etch primers or in pretreatment step prior to two-step self-etch adhesive and antibacterial adhesive could improve bond stability of self-etch cemented fiber post. However, none of these was capable of inhibiting bond degradation over time. Key words:Push-out bond strength, Fiber post, Chlorhexidine.

Adhesive interface and microtensile bond strength evaluation of four adhesive systems to primary dentin

ObjectivesThe aim of this study was to evaluate the microtensile bond strength and the adhesive interface of four adhesive systems to primary dentin. MethodsSixteen sound human primary molars were ground flat to expose dentin and randomly divided into four experimental groups according to the different adhesive material evaluated: three self-etching systems (Clearfil™ Protect Bond, Clearfil™ S3 Bond Plus and Futurabond® U) and one etch-and-rinse system (Prime&Bond® NT). The adhesives were applied under manufacturer's instructions and the crowns “restored” with a composite resin (Synergy® D6). The “restored” teeth were then cross-sectioned to obtain sticks. Each stick was evaluated using a microtensile test in a universal testing machine. Additionally, eighteen dentin samples from four temporary molars were prepared for dentin conditioning and interface morphology evaluation using scanning electron microscopy. The bond strength results were analyzed using one-way ANOVA and a Tukey HSD test (confidence level of 95%). ResultsClearfilTMS3 Bond Plus (47,28MPa), Prime&Bond® NT (43.11MPa) and Clearfil™ Protect Bond (40.33MPa), presented the highest adhesion values without statistical differences. Futurabond® U bond strengths (35.16MPa) was statistically similar to Clearfil™ Protect Bond (p=0.271) but significantly lower from Prime&Bond® NT (p=0.022) and Clearfil™ S3 Bond Plus (p<0.001). An ultra-morphological evaluation showed marked differences in smear layer dissolution, depth of dentin demineralization and thickness of the hybrid layer promoted by the different adhesive strategies evaluated. ConclusionsConsidering the limitations of this in vitro study, some self-etch adhesives may be capable of producing high bond strengths to primary dentin, similar to the etch-and-rinse adhesive evaluated.

Comparison of the Antibacterial Efficacy of Several Dentin Bonding Agents: Two Different in Vitro Studies

Objective: In this study, we compared the antibacterial effects of several dentin bonding agents with different pH values and active monomers. Method and Materials: Infected dentin samples were obtained from depths of approximately 4-6 mm, from isolated and air-dried dental caries. Streptococcus mitis was isolated and incubated on sheep blood agar plates at 37°C for 18 h. Impregnated antimicrobial disks were used for the liquids, and the samples were grouped as follows: group 1 was a negative control group with nothing applied; group 2 was a positive control group with 2% chlorhexidine digluconate applied; group 3 had Adper Single Bond Universal applied; group 4 had Clearfil SE Bond 2 (including 10-methacryloyloxydodecyl dihydrogen phosphate[MDP]) applied; group 5 had Clearfil S3 Bond Plus (including [MDP])applied; and group 6 had Clearfil Protect Bond (including 12-methacryloyloxydodecylpyridinium bromide [MDPB])applied. The antimicrobial disks were inserted into the blood agar plates. Inhibition zones were measured on the plates by well-educated specialists. Results: The 2% chlorhexidine digluconate solution had a more extensive inhibition zone than the other groups. S. mitis was significantly inhibited on the MDPB-impregnated disks applied to the agar plates. Conclusions: The results demonstrated that dentin bonding agents including MDPB-containing primer had significant antibacterial effects.

Antimicrobial Potential of Papain Chemomechanical Agent on Streptococcus Mutans and Lactobacillus Casei Followed by the Use of Self-Etching Adhesive Systems.

This study evaluated the antimicrobial effect of papain-based gel (Papacárie/ P) followed by self-etching adhesive systems with MDPB monomer (Clearfil Protect Bond/ PB) and without (Clearfil SE Bond/ Cl) on Streptococcus mutans (Sm) and Lactobacillus casei (Lc). The dentin of twenty human teeth was exposed to prepare four cylindrical cavities in each tooth. The cavities were incubated with Sm or Lc. One cavity from each tooth served as contamination control (positive control group); the other three were treated with P, P+CL and P+PB. The cavities were sealed and after 72 h, dentin samples were collected and microbial cultivation was performed. Microbial count was undertaken (CFUs/mg) according to the morphological characteristics for Sm and Lc. Analysis of variance and Tukey's test were applied (α=5%). For Sm, groups P+Cl and P+PB had lower microbial count than group P (no statistical differences between P+Cl and P+PB). For Lc, group P+Cl had microbial count similar to group P. There was statistical difference between cavities treated with P and P+PB but none between groups P+Cl and P+PB. After using P, both self-etching adhesives showed antimicrobial potential, although Clearfil Protect Bond proved better against Lc. Both self-etching adhesives used after application of Papacárie showed antimicrobial potential, although Clearfil Protect Bond proved more effective against Lactobacillus casei.

Response of exposed human pulp to application of a hemostatic agent and a self-etch adhesive

Objectives: The aim of this study was to investigate the human dental pulp response after use of a hemostatic agent (Ankaferd Blood Stopper [ABS]) and a self-etching adhesive system (Clearfil Protect Bond [CPB]) in direct pulp capping.Materials and methods: For the first aim, 21 non-carious human third molar teeth scheduled for extraction were selected. Class I cavities with pulp exposures were prepared. In group 1, bleeding was controlled with sterile cotton pellets and restored with calcium hydroxide (CH) + ZnOE cement + amalgam. In group 2, bleeding was controlled with sterile cotton pellets and restored with CPB and a composite resin. In group 3, bleeding was controlled with ABS and restored with CPB and a composite resin. The teeth were extracted after 90 days, formalin-fixed, and prepared for histological investigation. The pulp response was categorized using the following criteria: inflammatory response, soft tissue organization, reparative dentine formation, and bacterial staining. Data were submitted to statistical analysis, using nonparametric Kruskal–Wallis test.Results: In pulp response study, it showed no statistically significant differences between groups for all parameters (p > 0.05).Conclusions: The application of CPB and ABS in direct contact with the mechanically exposed pulp of healthy human teeth can lead to acceptable repair of the dentine–pulp complex, such as wound healing with tertiary dentine bridge formation.

The Effect of Decalcified Root Surfaces on Dentinal Bond Strength

Microtensile bond strengths of current dentin adhesives to intact and decalcified root surfaces were evaluated. Two hundred and twenty-four extracted human incisors were divided into two groups as intact (IRD) and decalcified (DRD). The roots of DRD teeth were placed in a demineralization solution to produce artificial carious-like lesions. Root surfaces were slightly ground and treated with either Scotchbond Multi-Purpose (SMP), Adper Single Bond Plus (SBP), Adper Easy Bond (AEB), Scotchbond SE (SSE), Clearfil SE Bond (CSE), Clearfil Protect Bond (CPB), Clearfil Tri-S Bond (CTS), FL-Bond II (FLB), XP Bond (XPB), iBond (IB), AdheSE Bond (ASE), Optibond Solo Plus (OSP), Prelude Dental Adhesive (PDA), and G-Bond (GB). Composite build-ups were formed on the bonded surfaces. After thermocycling, hour-glass shaped specimens with an area of 1 mm2 at the bonded interface were subjected to microtensile testing. Resin–dentin interfaces were observed with SEM. Kruskal Wallis and Mann Whitney-U tests were used for statistical analysis. There was not significant difference between bond strengths to intact and decalcified dentin, with the exception of ASE and CSE, which had higher values to IRD (p < 0.05). SSE and CTS were the adhesives that showed higher bond strengths to DRD than to IRD, however the difference was not significant (p > 0.05). The self-etch adhesives performed better on both IRD and DRD surfaces than etch-and-rinse systems.

Wall-lesion development in gaps: The role of the adhesive bonding material

ObjectivesThis study evaluated the caries wall lesion development in different composite–dentin interfaces to investigate if the presence and location of two bonding materials in the gaps influence wall caries lesion development. MethodsFourteen volunteers wore a modified occlusal splint containing samples with four different interfaces: perfect bonding/no gap, or with a fixed gap (234±30μm) with either no bonding material, bonding material (Clearfil Protect Bond–PB and Clearfil SE Bond–SE) on dentin or on composite. Eight times a day, the samples were dipped in 20% sucrose solution for 10min, during 3 weeks. The samples were imaged with microradiography (T-WIM), and lesion depth (LD) and mineral loss (ML) were measured. The data were analysed with paired t-test. ResultsThe perfect bonding group did not show any caries wall lesion development, whereas all other interfaces did. The interface with bonding on dentin did not show significantly different wall lesion development from the interface with no material. However, when bonding was present on composite, both LD and ML were significantly higher than both other gap conditions (p-values<0.05). A difference between the bonding material was only seen when applied on composite: PB showed less ML than SE (p=0.01). ConclusionsThe presence of bonding on the composite side of a composite–dentin gap increased wall lesion development in situ. Clinical significanceThe presence and location of an adhesive bonding material in the composite–dentin gaps plays a role on the wall caries lesion development.