Research progress on fluoride-releasing restorative materials for caries control / 口腔疾病防治

@#Restorative materials such as conventional glass ionomer cement (CGIC), resin-modified glass ionomer cement (RMGIC), polyacid-modified composite resin (compomer), and giomer have the properties of fluoride release and refill, which may prevent or slow down the progression of caries. The caries resistance of these materials was evaluated according to the following criteria: fluorine-releasing ability, antibacterial activity, mechanical properties and anti-aging properties. The anti-caries effect of these materials mainly depends on the effect of fluoride ions on mineralization. However, materials with strong fluorine release ability, such as CGIC, are mainly used in pediatric dentistry and temporary restoration due to their poor mechanical properties. It is difficult to achieve both fluoride ion release potential and mechanical strength, and there are few materials that can provide ideal mechanical strength while maintaining a high standard of fluoride release. The fluoride releasing and recharging capacity of CGIC, RMGIC, compomer and giomer decrease successively. The trend of material modification, to a certain extent, tends to sacrifice the fluoride release capacity of materials to maintain the ideal mechanical strength. In recent years, scholars have tried to add a variety of fillers to further enhance the anti-cracking ability of materials and add antibacterial agents to compensate for the anti-caries effect to reduce the loss of fluoride release.

Effect of fluoride varnish, glass ionomer and resin sealant on the prevention of pit and fissure caries in young children / 口腔疾病防治

Objective @# To study the effect of fluoride varnish, glass ionomer and resin sealant on the prevention of pit and fissure caries in young children, and to identify an a method to reduce the sensitivity of operation technique to prevent pit and fissure caries in young children with limited moisture isolation.@*Methods@# A self-control design was used to select 370 young children aged 3 to 5. Eight molars in the mouth were distributed in four quadrants, and each quadrant was randomly allocated to the blank group, fluoride varnish Duraphat group, glass ionomer GC FujiⅦ group, and resin ClinproTM Sealant group. The retention rate of pit and fissure sealant and the incidence of primary molar caries were observed in the 6th, 12th, 24th and 36th months respectively.@* Results @# In the 6th month, 12th month and 24th month, there were no significant differences in the material retention rate between the GC Fuji Ⅶ group and ClinproTM Sealant group. In the 36th month, the retention rate of the ClinproTM sealant group was better than that of the GC Fuji Ⅶ group (P < 0.05). In the 6th month, the caries incidence in the Duraphat group, GC Fuji Ⅶ group and ClinproTM sealant group was significantly lower than that in the blank group (P < 0.001). There was no significant difference between the Duraphat group, GC Fuji Ⅶ group and ClinproTM sealant group. In the 12th month, 24th month and 36th month, the incidence of caries in the GC Fuji Ⅶ group and ClinproTM sealant group was lower than that in the Duraphat group and blank group (P < 0.001), but there was no significant difference between the blank group and Duraphat group, and there was no significant difference in caries incidence between the GC Fuji Ⅶ group and ClinproTM sealant group.@*Conclusion @#The GC Fuji Ⅶ and ClinproTM sealant treatments continuously and effectively prevented pit and fissure caries compared with simple fluoride application. However, in cases of limited cooperation and poor moisture isolation in young children, the preventive measures of glass ionomer pits and fissure sealants (GC Fuji Ⅶ) are simpler and more feasible.

Research progress on nano-calcium phosphate modified dental materials for the prevention and treatment of dental pulp diseases / 口腔疾病防治

@#Nanomaterials usually refer to tiny particles with a diameter of 1-100 nm, which often have unique physicochemical properties and are one of the main areas of research interest for development of dental biomaterials. Nano-calcium phosphate modified dental materials have been widely used in pit and fissure sealing, dental resin restoration, tooth adhesion, and root canal sealing. The current research shows that the dental material modified by nano-calcium phosphate has stronger mechanical properties and shows long-term calcium and phosphorus ion release and excellent ion recharging ability, which can promote the remineralization of tooth hard tissue and has good prospects for application. However, it is difficult to accurately simulate the complex environment of the oral cavity. Therefore, the biocompatibility, cytotoxicity and effect of clinical application of nano-calcium phosphate modified dental materials still needs further study. This review summarizes and discusses the recent research progress regarding nano-calcium phosphate modified dental materials in the prevention and treatment of dental pulp diseases.

Review and suggestion on the evaluation of the effect and the benefit of a pit and fissure sealant project / 口腔疾病防治

@#As a professional method to prevent decayed teeth and an oral public health project, pit and fissure sealant is widely used domestically. How to evaluate the effect and benefit of the community pit and fissure closure project, especially the community full coverage pit and fissure closure project, requires investigation. The Guangzhou Children′s Pit and Fissure Sealing Project was carried out in an orderly manner and was administered normatively. A retrospective cohort study with use of a sample survey was used in this program. According to cavity occurrence and reservations of sealant in the first permanent molar, the samples were divided into the following two groups: the sealing group with indication and the sealing group without indication. Reservations of sealant, cavity incidence, reduced incidence, net profit, cost-effectiveness and cost-benefits of the program were evaluated. Some promotable experiences were summarized during this project. Various relevant theories and reports of the pit and fissure sealant project evaluation were reviewed and previous studies were discussed in this article. By analyzing the methods and results of the pit and fissure sealant project in Guangzhou, suggestions are made for project evaluation, especially sample grouping and evaluation indicators, which was refer to a further study for the pit and fissure sealing project.

Evaluation of High-power Light Emitting Diode Curing Light on Sealant Polymerization / 대한소아치과학회지

This study aimed to determine whether the curing times of Xtra Power and High Power modes of high-power light emitting diode (LED) curing light are sufficient for polymerization of resin sealants. The specimens were prepared and their microhardness values were measured and compared with those of specimens polymerized under conventional LED curing light.The filled sealant polymerized for 8 seconds in the High Power mode and for 3 seconds in the Xtra Power mode showed significantly lower microhardness than the control specimen (p = 0.000). The unfilled sealant polymerized for 8, 12 seconds in the High Power mode and for 6 seconds in the Xtra Power mode showed significantly lower microhardness than the control specimen (p = 0.000).The results of this study suggest that the short curing time with the Xtra Power and High Power modes of highpower LED curing light are not sufficient for adequate polymerization of sealants under specific conditions, taking into account the curing times and the type of sealant.

Clinical efficacy of the glass ionomer cement used as pit and fissure sealant with and without acid etching in primary teeth / 华西口腔医学杂志

OBJECTIVE@#This work aimed to compare the effect of retention and preventive caries of the pit and fissure sealant on primary teeth by using glass ionomer cements (GIC) with or without acid etching technique.@*METHODS@#In this clinical trail, 100 children aged 3-4 years old with a split-mouth design were equally divided into two groups (the left second upper and lower mandibular primary molars were present in group A, and the right second upper and lower mandibular primary molars were present in group B; each group had 200 molars). All participants were placed in pit and fissure sealant with Ketac® Molar Easymix and seated with atraumatic restorative treatmen press-finger technique in the two groups. Group A was subjected to acid etching (40 s, 35% H₃PO₄), while group B were not subjected to acid etching. GIC preservation rate, caries rate, and decayed teeth (dt) index were observed after 12 months.@*RESULTS@#After a 12-month follow-up period, the completely lost, partially losing, and losing rates of GIC in 86 children (172 second primary molars) were 83.14%, 9.88%, 6.98% in group A and 62.79%, 20.35%, and 16.86% in group B, respectively. The differences between the two groups were insignificant (P<0.05). The caries rates of groups A and B were 8.14% and 16.86%, and their dt indices were 0.08±0.31 and 1.17±0.46, respectively, thereby indicating significant difference between the two groups (P<0.05).@*CONCLUSIONS@#Using acid etching technology, the retention rate of the pit and fissure sealant increased, while its losing rate decreased. The retention effect of the GIC was improved, and the dental caries prevention effect was enhanced. Sealant processing was a self-curing procedure that sets without the external energy. Hence, this procedure is suitable for the preventive caries of primary teeth in children.

Penetration and Microleakage Assessment of Flowable Resin Applied on Carious Fissure Following Various Fissurotomy Techniques / 대한소아치과학회지

The purpose of this study was to evaluate the effect of fissurotomy on the penetration and microleakage of flowable resins for carious fissures. A total of 250 extracted premolars with early fissure caries were selected and divided into five groups according to the fissurotomy; no fissurotomy (n = 50), fissurotomy with Fissurotomy® original bur (n = 50), fissurotomy with Fissurotomy® Miro NTF bur (n = 50), fissurotomy with SF104R tapered diamond bur (n = 50), fissurotomy with 1/2 round carbide bur (n = 50). Two types of flowable resins (UniFil®Flow, Filtek®Flow) were used as sealing materials. All samples were sectioned and observed using a stereoscopic microscope after thermocycling and immersing in methylene blue solution. The adaptation of flowable resin to the fissure wall was observed using scanning electron microscopy. The penetration of flowable resin into the carious fissure was significantly increased by fissurotomy, which also decreased microleakage. Fissure preparation using different burs showed a significantly different in penetration, but did not show any difference in microleakage. Unifil®Flow showed better penetration than Filtek®Flow, but there was no significant difference in microleakage. Fissurotomy can be used to increase the penetration of flowable resin into carious fissures and decrease microleakage.

In-vitro comparative study of marginal leakage and penetration ability of moisture-tolerant and conventional resin-based pit and fissure sealants with different surface preparations

This in-vitro study aimed to evaluate and compare the marginal leakage and penetration ability of a moisture-tolerant (Embrace WetBondTM) and a conventional (ClinproTM) resin-based sealants under three different enamel surface preparations (acid etched, acid etched and saliva contaminated and bur preparation and acid etched). One hundred and twenty extracted caries free human premolars teeth were cleaned and randomly divided into six groups of equal numbers, according to the type of sealants used and surface preparations. All the sealed teeth were subjected to thermocycling and immersed in a methylene blue dye. Each tooth was then embedded into acrylic resin before it was sectioned into four sections per tooth. Marginal leakage and unfilled surface area (indicating penetration depth of resin) were then measured using an optical 3D measurement device (Alicona Infinite Focus®). Both sealants exhibited comparable proportion of marginal leakage on acid etched only surfaces. Moisture-tolerant sealant showed the least proportion of marginal leakage on bur prepared and etched surfaces. Presence of saliva has detrimental effect on adhesion of both sealants. Nevertheless, depth of penetration of sealant into the fissures is comparable with both sealant types irrespective of the surface preparations.

Epidemiological investigation of dental health status of 6-8 years old children in Zhongkai Hi-Tech Zone of Huizhou / 口腔疾病防治

Objective@#To investigate the status of tooth caries of 6-8 years old school children in Zhongkai Hi-Tech Zone of Huizhou city, and to provide scientific data for prevention and treatment on caries. @*Methods @# Referring to the Guideline for the 3rd National Oral Health Survey, the dental caries status of 1-2 grade students in 32 primary schools were investigated, and the data were analyzed by SPSS 14.0 statistical software.@*Results @# The prevalence rate of deciduous teeth caries in 4 390 children was 67.4%, and the DMFT was 3.94; The eruption rate of the first molars was 81.5%, with the prevalence rate of caries was 24.3%, and the DMFT was 0.448. The rate of caries for 8 years old children is higher than in 6-7 years old children (P < 0.001). @*Conclusion@#There is a high caries rate in children in Zhongkai Hi-Tech Zone of Huizhou, so oral health education, primary teeth caries treatment, and fissure sealant of permanent teeth should be strengthened.

Epidemiological analysis of dental caries among pupils in Shenzhen city / 口腔疾病防治

Objective@#To understand the distribution and treatment of dental caries among primary school students in Shenzhen City, and to provide a basis for prevention and treatment of dental caries of primary school students in Shenzhen City.@*Methods @#Using cluster sampling method, in the 10 districts of Shenzhen city, a total of 74 308 students in 63 primary school, were randomly selected and received examination of dental caries.@*Results@# Prevalence of caries was 15.7%. Decayed, missing and filled teeth (DMFT) was 0.37 ± 0.18. Significant differences in age and gender distribution were found (P < 0.05). There is a correlation between prevalence of permanent teeth caries and age (P < 0.05). Rate of pit and fissure sealant, filling in permanent teeth were 31.17%, 19.05%. Controlling age and gender factors, significant differences between genders were found in rate of pit and fissure sealant, filling in permanent teeth (P < 0.05).@*Conclusion@# Prevention of dental caries for pupils in Shenzhen city needs to be strengthened.

The relationship between pit and fissure sealant (PFS) experience and the socio-economic factors of adolescents before and after coverage by National Health Insurance (NHI) / 대한구강보건학회지

OBJECTIVES: The purpose of this study was to review the relationship between pit and fissure sealant (PFS) experience and the socio-economic factors of adolescents before and after coverage by National Health Insurance (NHI). METHODS: Our sources were the Korea Youth Risk Behavior Web-based Surveys from 2008 and 2014. The variables used were PFS experience, demographic factors, socio-economic factors, and oral health-related behaviors. RESULTS: PFS experience was higher in 2014 than in 2008. The relationship between PFS experience and socio-economic factors was significant in both 2008 and 2014. Although the inequity of PFS experience among adolescents was reduced as PFS was included in NHI coverage, a disparity still exists. CONCLUSIONS: Even after NHI coverage included PFS, the policies to reduce the inequity of PFS experiences among adolescents should be further devised. In addition, a longitudinal study is recommended to determine the relationship between PFS experience and various socio-economic or behavioral factors.

Estudio comparativo in vitro de diferentes métodos de profilaxis y acondicionamiento del esmalte en la capacidad de adhesión de un sellador de fosas y fisuras / In vitro comparative study of different methods of prophylaxis and conditioning of enamel in the adhesiveness of a pit and fissure sealant

El objetivo de este estudio comparativo in vitro fue evaluar y comparar el efecto de diferentes métodos de profilaxis y acondicionamiento del esmalte, en la capacidad de adhesión de un sellador de fosas y fisuras fotopolimerizable. La porción coronaria de 50 premolares extraídos se seccionaron en dos mitades (vestibular y lingual) y se incluyeron en bloques de acrílico. Las muestras se dividieron en cinco grupos de acuerdo con los métodos de profilaxis: sin profilaxis, piedra pómez, gluconato de clorhexidina, pasta fluorada y limpiador por bicarbonato (air prophy); y técnicas de acondicionamiento del esmalte: grabado ácido con ácido fosfórico al 37% y adhesivo de autograbado. La fuerza de adhesión del sellador se midió en una máquina Instron® mediante una prueba de tracción. Los resultados no demostraron diferencias significativas en la resistencia a la tracción de acuerdo a las técnicas de acondicionamiento del esmalte utilizadas. En relación con los métodos de profilaxis estudiados, se observó que existieron diferencias significativas en los grupos tratados con pasta fluorada y limpiador por bicarbonato.

The aim of this in vitro comparative study was to evaluate and compare the effect of different methods of prophylaxis and conditioning of enamel, in the adhesiveness of a light-curing pit and fissure sealant. The coronal portion of 50 extracted premolars were sectioned into two halves (buccal and lingual) and embedded in acrylic blocks. The samples were divided into five groups according to the methods of prophylaxis: no prophylaxis, pumice powder, chlorhexidine gluconate, fluoridated paste and air prophy; and enamel conditioning techniques: etching acid with 37% phosphoric acid and self-etching adhesive. The sealant adhesion strength was measured using an Instron® machine for a tensile test. The results showed no significant differences in tensile strength according to the enamel conditioning techniques used. Regarding the methods of prophylaxis under study, a significant difference in groups treated with fluoridated paste and air prophy was observed.

Comparison of supplied amount of pit and fissure sealing on the first permanent molars by age and disparity of dental accessibility using National Health Insurance data / 대한구강보건학회지

OBJECTIVES: The purpose of this study was to review the supplied amount of pit and fissure sealing (PFS) by age and dental accessibility of children after PFS was included in the list of treatments covered by National Health Insurance (NHI). METHODS: The comparison period was selected by considering the availability of data and the initiated time of PFS inclusion into NHI. The selected data period after inclusion was 2010-2012. Data were collected from the NHI database. To categorize the areas by high and low dental accessibility, the number of dental institutions was standardized by population per width of area. RESULTS: Supplied amount of PFS to the first permanent molars in children aged 6 to 8 years constituted to about 70% of the total supplied amount during 2010-2012. However, this supplied amount was less than 8% of the total number of the first permanent molars in that age group. Number of supplied PFS for ages 6 to 8 years was 8.4% and 6.3% of the total number of first permanent molars for high and low dental accessibility areas, respectively. CONCLUSIONS: Although PFS supply was increased after inclusion in NHI coverage, it is still insufficient to reduce the decayed-missing-filled teeth (DMFT) index effectively. To increase the supplied amount of PFS and to reduce inequality of supply between areas of high and low dental accessibility, strengthening of and focus on education related to PFS, reduced out-of-pocket expenditure, and advocacy are needed for appropriate target age groups and areas.

The influence of different etching adhesive systems on flowable resin used as pit and fissure sealant / 实用口腔医学杂志

Objective:To evaluate the effects of the flowable resin used as pit and fissure sealant using different etching adhesive systems.Methods:60 caries-free extracted human premolars were randomly divided into 4 groups(n =1 5)and treated by Gluma, NT and 3M-Z350 flowable resin(group A);Clearifil SE Bond adhesive and 3M-Z350 flowable resin(group B),phosphoric acid etching,3M-Z350 flowable resin and phosphoric acid etching(group C)and 3Mconcise sealant(group D)respectively.After pro-cessing the tooth surface the pit and fissue of 1 0 sample in each group were sealed.The microleakage was measured by 1 % methyl-ene blue staining(n =8).The material-enamel interface was observed by SEM(n =2).The shear bond strength of the column-shaped samples with the diameter and the height of 3 mm(n =5)on the mesial or dental surface was examined by a test machine. The sealant cartridges and flowable resin cartridges with the diameter and height of 4 mm were used for the crushing strength exami-nation(n =1 0).Results:There was no significant difference in the microleakage among the 4 groups.SEMobservation showed that the resin tags of group A were long and dense and the resin tags of group B were short and sparse,bubbles and cracks were found on the local site in group A and B.The resin tags of group C were long and thin,but combined with tooth tightly;the resin tags of group D were short and dense;the penetration was poor at the bottom of the fissures in the 4 groups.The shear bond strength of Group A was the highest(P 0.05).The compressive strength of flowable resin groups was higher than that of fissure seal-ant group(P <0.05).Conclusion:The shear bond strength and compressive strength of all-etching bonding system combined with flowable resin is superior to that of self-etching bonding system combined with flowable resin and the traditional sealant.Using Prime&Bond NT bond after acid etching may improve the shear bonding strength.

Changes in the amount of pit and fissure sealants supplied in Korea after inclusion in the National Health Insurance coverage / 대한구강보건학회지

OBJECTIVES: The purposes of this study were to review changes in the amount of pit and fissure sealant (PFS) provided after the inclusion of PFS in treatments covered by the National Health Insurance (NHI) and to assess differences in the supplied amount between geographical areas where accessibility to dental care differs. METHODS: The years for comparison were selected based on data availability and the time of inclusion of PFS into NHI coverage. The selected pre-inclusion year was 2008, and the post-inclusion year was 2012. Data regarding the amount of PFS supplied were collected from the oral health program, NHI, and Medical care. To dichotomize areas by high and low dental care accessibility, we standardized the population size, number of dental institutions, and number of dentists in each group. RESULTS: We considered metropolitan areas and Gyeonggi Province as high dental care accessibility areas, while other provinces were considered as low dental care accessibility areas. Regardless of the transforming constant, the amount of PFS supplied increased in high dental care accessibility areas and decreased in low dental care accessibility areas after inclusion of PFS in NHI. CONCLUSIONS: To increase the amount of PFS provided in low dental care accessibility areas, promotion of PFS should be strengthened and support from oral health programs should be increased. Additionally, waiving out-of-pocket money for PFS in NHI should be considered to remove barriers of supply.

Enamel pretreatment with Er:YAG laser: effects on the microleakage of fissure sealant in fluorosed teeth

OBJECTIVES: The purpose of this in vitro study was to evaluate the microleakage and penetration of fissure sealant in permanent molar teeth with fluorosis after pretreatment of the occlusal surface. MATERIALS AND METHODS: A total of 120 third molars with mild dental fluorosis were randomly divided into 6 groups (n = 20). The tooth surfaces were sealed with an unfilled resin fissure sealant (FS) material. The experimental groups included: 1) phosphoric acid etching (AE) + FS (control); 2) AE + One-Step Plus (OS, Bisco) + FS; 3) bur + AE + FS; 4) bur + AE + OS + FS; 5) Er:YAG laser + AE + FS; and 6) Er:YAG laser + AE + OS + FS. After thermocycling, the teeth were immersed in 0.5% fuchsin and sectioned. Proportions of mircoleakage (PM) and unfilled area (PUA) were measured by digital microscope. RESULTS: Overall, there were significant differences among all groups in the PM (p = 0.00). Group 3 showed the greatest PM, and was significantly different from groups 2 to 6 (p < 0.05). Group 6 showed the lowest PM. Pretreatment with Er:YAG with or without adhesive led to less PM than bur pretreatment. There were no significant differences among groups in PUA. CONCLUSIONS: Conventional acid etching provided a similar degree of occlusal seal in teeth with fluorosis compared to those pretreated with a bur or Er:YAG laser. Pretreatment of pits and fissures with Er:YAG in teeth with fluorosis may be an alternative method before fissure sealant application.

The effects of surface glazing materials on dental sealant surface hardness and roughness / 대한구강보건학회지

OBJECTIVES: To assess the effect of glazing materials with different sealants on sealant surface roughness and surface hardness. METHODS: Ultraseal XT(TM) sealant (group 1) and 3M Concise(TM) sealant (group 2) were applied on the buccal surfaces of 26 bicuspid teeth per group. The buccal surface of each tooth was then divided into two half surfaces for 52 halves per group. BisCover LV(TM) glaze was applied to one of the two buccal half surfaces of randomly selected 13 teeth per group. For the other remaining 13 teeth per group, we applied Fortify(TM) glaze to one of the two half surfaces. The remaining 26 buccal half surfaces per group covered with sealant only, did not receive any glaze. The surface roughness and hardness of each sample was measured, and the average value of the three measurements from the individual sample was calculated. The sample surfaces were also observed by scanning an electron microscopy. RESULTS: Two-way ANOVA with surface roughness and hardness as the individual dependent variables identified a statistically significant interaction between the sealants and glazing materials. BisCover LV lowered Ultraseal XT surface roughness and application of surface glazing materials on 3M Concise promoted the hardness. Micro-cracks were identified on the surface in no glaze compared to being less in any glaze. CONCLUSIONS: Surface glaze material could improve the surface roughness and hardness of the selected pit and fissure sealant material. Such a sealant-reinforcing procedure, involving surface glazing, may be clinically useful.

The relationship of pit and fissure sealant in children and mother's socioeconomic status, mother's oral-health screening / 대한구강보건학회지

OBJECTIVES: This study examines the relationship between the implementation of pit and fissure sealant in children, and the prevention level of teeth based on household income by a cross-sectional study. METHODS: The study population consisted of a representative community sample of 1,701 subjects, ranging from 6-18 years in children and over 27 years in mothers, from the 4th Korea National Health and Nutrition Examination Surveys in 2009. Mother's indicators included age, occupation, education, household income, smoking, brushing frequency, oral health screening, self-related oral health, and mother's concern. We used a multiple logistic regression to identify and quantify the risk factors for the pit and fissure sealant. RESULTS: In multiple analyses, age of children, household income level, and oral health screening were significant factors for the implementation of pit and fissure sealant for the children. The multiple-adjusted odds ratio (95% confidence interval) for the implementation of pit and fissure sealant, comparing the lowest to 101-200, 201-300, 301-400, 401-500 and 501 ten thousand Korean Won or more were 2.2 (1.15-4.10), 2.5 (1.38-4.61), 2.0 (1.04-3.90), 2.8 (1.46-5.53), and 3.6 (1.82-6.94), respectively. CONCLUSIONS: It was concluded that the implementations of the pit and fissure sealant were positively related with the household income level and mother's oral health screening.

Bonding agent underneath sealant: shear bond strength to oil-contaminated

This study evaluated in vitro the shear bond strength of a resin-based pit-and-fissure sealant (Fluroshield - F) associated with either an ethanol-based (Adper Single Bond 2 - SB) or an acetone-based (Prime & Bond - PB) adhesive system under conditions of oil contamination. Mesial and distal enamel surfaces from 30 sound third molars were randomly assigned to 2 groups (n=30): I - no oil contamination; II - oil contamination. Contamination (0.25 mL during 10 s) was performed after 37 percent phosphoric acid etching with an air/oil spray. The specimens were randomly assigned to subgroups, according to the bonding protocol adopted: subgroup A - F was applied to enamel without an intermediate bonding agent layer; In subgroups B and C, SB and PB, respectively, were applied, light-cured, and then F was applied and light-cured. Shear bond strength was tested at a crosshead speed of 0.5 mm/min in a universal testing machine. Means (± SD) in MPa were: IA-11.28 (±1.84); IIA-12.02 (±1.15); IB-9.73 (±2.38); IIB-9.62 (±2.29); IC-28.30 (±1.63); and IIC-25.50 (±1.91). It may be concluded that the oil contamination affected negatively the sealant bonding to enamel and the acetone-based adhesive system (PB) layer applied underneath the sealant was able to prevent its deleterious effects to adhesion.

Este estudo avaliou in vitro a resistência ao cisalhamento (RC) de um selante resinoso [Fluroshield (F); Dentsply/Caulk] em associação com um sistema adesivo com solvente a base de etanol [Adper Single Bond 2 (SB); 3M/ESPE] ou a base de acetona [Prime & Bond (PB); 3M/ESPE] após contaminação com óleo do esmalte. Superfícies mesiais e distais de esmalte de 30 terceiros molares hígidos foram aleatoriamente alocadas em 2 grupos (n=30): I - contaminação com óleo; II - sem contaminação. A contaminação foi realizada (0,25 mL;10 s) com um jato de ar/óleo após o condicionamento do esmalte com ácido fosfórico a 37 por cento. Os espécimes foram aleatoriamente alocados em subgrupos, de acordo com a técnica adesiva empregada: A - F foi aplicado sobre o esmalte condicionado sem sistema adesivo; B - SB + F; C - PB + F. RC foi testada em uma máquina universal de ensaios (0,5 mm/min; 50 kgf) e os dados analisados por ANOVA e t-teste (α=0,01). As médias de RC em MPa foram: IA-11,28 (±1,84); IIA-12,02(±1,15); IB-9,73 (±2,38); IIB-9,62 (±2,29); IC-28,30 (±1.63); e IIC-25,50 (±1,91). Conclui-se que a contaminação com o óleo afetou a adesão do selante resinoso ao esmalte e o sistema adesivo com solvente a base de acetona (Prime & Bond) aplicado sob o selante foi capaz de impedir os efeitos deletérios da contaminação com óleo.

Bond strength of a pit-and-fissure sealant associated to etch-and-rinse and self-etching adhesive systems to saliva-contaminated enamel: individual vs. simultaneous light curing

This study evaluated in vitro the shear bond strength (SBS) of a resin-based pit-and-fissure sealant [Fluroshield (F), Dentsply/Caulk] associated with either an etch-and-rinse [Adper Single Bond 2 (SB), 3M/ESPE] or a self-etching adhesive system [Clearfil S3 Bond (S3), Kuraray Co., Ltd.] to saliva-contaminated enamel, comparing two curing protocols: individual light curing of the adhesive system and the sealant or simultaneous curing of both materials. Mesial and distal enamel surfaces from 45 sound third molars were randomly assigned to 6 groups (n=15), according to the bonding technique: I - F was applied to 37 percent phosphoric acid etched enamel. The other groups were contaminated with fresh human saliva (0.01 mL; 10 s) after acid etching: II - SB and F were light cured separately; III - SB and F were light cured together; IV - S3 and F were light cured separately; V - S3 and F were light cured simultaneously; VI - F was applied to saliva-contaminated, acid-etched enamel without an intermediate bonding agent layer. SBS was tested to failure in a universal testing machine at 0.5 mm/min. Data were analyzed by one-way ANOVA and Fisher's test (α=0.05).The debonded specimens were examined with a stereomicroscope to assess the failure modes. Three representative specimens from each group were observed under scanning electron microscopy for a qualitative analysis. Mean SBS in MPa were: I-12.28 (±4.29); II-8.57 (±3.19); III-7.97 (±2.16); IV-12.56 (±3.11); V-11.45 (±3.77); and VI-7.47 (±1.99). In conclusion, individual or simultaneous curing of the intermediate bonding agent layer and the resin sealant did not seem to affect bond strength to saliva-contaminated enamel. S3/F presented significantly higher SBS than the that of the groups treated with SB etch-and-rinse adhesive system and similar SBS to that of the control group, in which the sealant was applied under ideal dry, noncontaminated conditions.

Este estudo avaliou in vitro a resistência ao cisalhamento (RC) de um selante resinoso [Fluroshield (F), Dentsply/Caulk] em associação com um sistema adesivo de condicionamento total [Adper Single Bond 2 (SB), 3M/ESPE] ou auto-condicionante [Clearfil S3 Bond (S3), Kuraray Co., Ltd.] após contaminação salivar do esmalte, comparando dois protocolos: fotopolimerização individual do sistema adesivo e do selante ou simultânea de ambos os materiais. Superfícies mesiais e distais de esmalte de 45 terceiros molares hígidos foram aleatoriamente alocadas em 6 grupos (n=15), de acordo com a técnica adesiva empregada: I - F foi aplicado sobre o esmalte condicionado com ácido fosfórico a 37 por cento. Os demais grupos foram contaminados com saliva (0,01 mL por 10 s) após o condicionamento ácido. II - SB e F foram fotopolimerizados separadamente; III - SB e F foram fotopolimerizados simultaneamente; IV - S3 e F foram fotopolimerizados separadamente; V - S3 e F foram fotopolimerizados simultaneamente; VI - F foi aplicado sobre o esmalte condicionado e contaminado sem sistema adesivo. RC foi testada em uma máquina universal de ensaios (0,5 mm/min; 50 kgf) e os dados analisados por ANOVA a 1 fator e teste exato de Fisher (α=0,05). As interfaces adesivas foram analisadas quanto ao padrão de fraturas em estereomicroscópio. Três espécimes de cada grupo foram analisados qualitativamente em microscópio eletrônico de varredura. As médias de RC em MPa foram: I-12,28 (±4,29); II-8,57 (±3,19); III-7,97 (±2,16); IV-12,56 (±3,11); V-11,45 (±3,77); e VI-7,47 (±1,99). Conclui-se que a fotopolimerização individual ou simultânea do sistema adesivo e do selante não afetou os valores de RC ao esmalte contaminado. S3/F apresentou RC estatisticamente maior do que os grupos tratados com o sistema adesivo etch-and-rinse SB e estatisticamente semelhante ao grupo controle, no qual o selante foi aplicado em condições ideais, na ausência de contaminação salivar.