Antimicrobial action of new, proprietary lining cements

The antibacterial activity of innovative, commercial lining cements was investigated. A liner which contains calcium hydroxide and is polymerized by visible light (Prisma VLC Dycal) and a glass-ionomer lining cement (GC lining cement) were compared with two more established lining cements (Advanced Formula II Dycal and Life). Antibacterial activity and hemolysis-like agar change at 24, 48, and 72 hours were measured on blood agar plates inoculated with Streptococcus mutans KPSK 2 (serotype c), Lactobacillus casei ssp rhamnosus ATCC 11981, and chewing-stimulated saliva. Prisma VLC Dycal did not affect bacteria or agar. The glass-ionomer lining cement, with an acidic pH at setting, had the most pronounced effect on all test organisms and on the agar. Even after 48 hours' setting, it inhibited growth of S. mutans. The control lining cement (AFII Dycal) showed antibacterial activity toward both specific micro-organisms as well as some activity against the salivary organisms. The material Life showed only partial inhibition of microbial growth. For all lining cements, the hemolytic-like agar change correlated with antibacterial effects. The surface pH of the freshly-set cements containing calcium hydroxide was alkaline. It would seem that a simple correlation between high surface pH and antibacterial activity among these cements does not exist. Also, further biological characterization of new lining cements is required to direct their appropriate clinical use.     

Comparison of sealing efficacy of materials placed in lateral root perforations--an in vitro study

An endodontic perforation interferes with the principal goal of sealing the root canal system. An in vitro study was conducted on comparative efficacy of three materials-Dispersalloy, Cavit and Prisma VLC Dycal when placed in lateral root perforations in cervical third areas. Root canals were prepared and irrigated thoroughly. Perforations were made with No. 2 round bur and sealed with Dispersalloy, Cavit and Prisma VLC Dycal. Dispersalloy Group I showed best sealing ability. Prisma VLC Dycal Group I too was comparable to Dispersalloy Group I in its sealing ability, followed by Cavit Group II, Prisma VLC Dycal Group II, Dispersalloy Group II in that order. Cavit Group I was least effective in sealing perforations.     

Physical properties of calcium hydroxide and glass-ionomer base and lining materials

Compressive, diametral tensile and flexural strengths, moduli of elasticity, pH, and acid solubility values were compared for six calcium hydroxide cements, seven glass-ionomer cements, and one calcium aluminate cement. Results indicated that the glass-ionomer materials were generally stronger than the calcium hydroxide liners. Prisma VLC Dycal showed the lowest value for modulus of elasticity and the least acid solubility. The glass-ionomer materials were initially acidic, reaching a final pH between 5.4 and 7.3, whereas the calcium hydroxide and calcium aluminate cements were strongly alkaline at all time intervals.     

Immediate and delayed direct pulp capping with the use of a new visible light-cured calcium hydroxide preparation

The pulpal response to mechanical exposure and capping either immediately or after 24 hours was investigated in 64 teeth of four cynomolgus monkeys with the use of Dycal, VLC Dycal, or Prisma-Bond. All overlying amalgam restorations were surface-sealed with zinc oxide-eugenol cement. After 2 months the teeth were removed and prepared for histologic examination; dentine bridges were present in almost all teeth filled with Dycal or VLC Dycal, and pulpal inflammation was observed in only one tooth that showed evidence of infection. Dentine bridges were usually incomplete when Prisma-Bond was used, although pulpal inflammation was only observed in 2 of 22 teeth. The success rate of pulp capping delayed for 24 hours was as high as that for immediate capping.     

iBond粘结剂、Single Bond粘结剂用于比格犬直接盖髓术的组织学评价

[摘要] 目的 对第七代牙本质粘接剂iBond和第五代牙本质粘接剂Single Bond及VLC Dycal的体内细胞毒性进行研究。方法 选择4只比格犬共72颗健康牙齿,在颊面制备Ⅴ类洞并在洞底做人工穿髓孔,然后分为3组,第1组和第2组分别用Single Bond和iBond,第3组用VLC Dycal盖髓作为阳性对照组。选取比格犬口内剩余健康牙齿24颗,不做处理作为阴性对照组。所有实验牙齿分别在盖髓后的第7、30天拔出,并进行组织学评价。结果 7 d时,3组材料均出现不同程度的炎症反应和组织紊乱,但其差异无统计学意义;30 d时,iBond和VLC Dycal两组的炎症反应较Single Bond组弱,其差异有统计学意义(P<0.05);3组材料均有不同程度的组织紊乱,其差异无统计学意义;所有样本未见有牙本质桥形成。结论 iBond对牙髓的刺激性较小;Single Bond对牙髓的刺激性较大。     

Effect of the tenure dentin bonding system on leakage of light-activated liners

This study investigated the effect of the Tenure dentin bonding system on the sealing properties of four light-activated liners. Dentinal slot preparations were made in extracted human molars and "restored" with Cavalite, TimeLine, VLC Dycal, and Zionomer liners. Samples were immersed in 0.05 percent crystal violet solution for 2 hours, then embedded in clear casting resin, sectioned, and examined with an optical microscope. Our results indicated that the Tenure dentin bonding system reduced dye penetration around each of the light-activated liners tested. The Tenure/VLC Dycal system provided a more effective seal than the other liners.     

Effect of the Tenure Dentin Bonding System on Leakage of Light-Activated Liners

This study investigated the effect of the Tenure dentin bonding system on the sealing properties of four light-activated liners. Dentinal slot preparations were made in extracted human molars and "restored" with Cavalite, TimeLine, VLC Dycal, and Zionomer liners. Samples were immersed in 0.05 percent crystal violet solution for 2 hours, then embedded in clear casting resin, sectioned, and examined with an optical microscope. Our results indicated that the Tenure dentin bonding system reduced dye penetration around each of the light-activated liners tested. The Tenure/VLC Dycal system provided a more effective seal than the other liners.     

In vitro evaluation of pH changes induced by calcium hydroxide liners.

OBJECTIVES: Since the highly alkaline pH of calcium hydroxide is considered by many to be responsible for its biologic activity, the possible variations of pH induced by the different calcium hydroxide liners are accepted as a major concern. The aim of the present study was to determine the pH changes of five different calcium hydroxide liners and variations of pH levels at different time intervals. METHOD AND MATERIALS: The materials tested were Dycal, Life, Calic, Dycal VLC, and Calcident 450. Samples were prepared according to manufacturer instructions and by using plastic molds; five standard samples from each material were prepared. The samples were then placed in separate vials, containing 10 mL deionized water (pH 7.0), and stored at room temperature (200C). The pH measurements were taken 1 hour, 24 hours, 3 days, and 7 days after mixing. The pH variations of each material at the given time intervals were recorded, and the means were calculated. RESULTS: Statistical analysis showed significantly high differences between the mean pH values induced by each material at all time intervals. The highest value for the first-hour measurement was for Dycal VLC, and the highest values for the other time intervals were for Calcident 450. The pH values of the materials exhibited statistically significant differences among all the time intervals. CONCLUSION: All materials changed the pH of deionized water toward alkaline.     

Microleakage between Composite Resin and Basing Materials

This study investigated the microleakage between a composite resin restorative material and six basing materials. Cavities were prepared in polymerized composite resin samples and "restored" with Cavitec, Life, Ketac-Bond, BaseLine, Cavalite, and VLC Dycal. The samples were thermocycled and immersed in 0.05 percent crystal violet solution for 2 hours, then embedded in clear casting resin, sectioned and examined with an optical microscope. Our results indicated that Cavalite and VLC Dycal allowed no dye penetration. Cavitec and Life had a moderate degree of dye penetration and Ketac-Bond and BaseLine had a relatively high degree of penetration.     

Microleakage between composite resin and basing materials.

This study investigated the microleakage between a composite resin restorative material and six basing materials. Cavities were prepared in polymerized composite resin samples and "restored" with Cavitec, Life, Ketac-Bond, BaseLine, Cavalite, and VLC Dycal. The samples were thermocycled and immersed in 0.05 percent crystal violet solution for 2 hours, then embedded in clear casting resin, sectioned and examined with an optical microscope. Our results indicated that Cavalite and VLC Dycal allowed no dye penetration. Cavitec and Life had a moderate degree of dye penetration and Ketac-Bond and BaseLine had a relatively high degree of penetration.     

Adaptation of two different calcium hydroxide bases under a composite restoration

A preliminary scanning electron microscope (SEM) study was carried out to investigate how the adaptation of two calcium hydroxide bases (one chemically cured, one light cured) was affected by the polymerization contraction of a supervening light-cured composite resin restoration. Occlusal cavities were prepared in 40 sound extracted human premolars, divided into two equal groups. In the first group a chemically cured calcium hydroxide (Dycal, De Trey Dentsply, Konstanz, FRG) was placed as a base. In the second group a new light-cured calcium hydroxide product (Prisma VLC Dycal, De Trey Dentsply) was used. The restorations were completed with an acid-etched, incrementally placed composite resin. The specimens were sectioned vertically and debrided. A replica was made of each half-tooth. The interfaces between composite resin/base and base/dentine were viewed and photographed in the SEM. The marginal adaptation at these two interfaces was classified into three categories according to the extent of the gaps that were observed. Prisma VLC Dycal base was found to be pulled away from the dentine floor of the cavity as a result of an apparent adhesion to the composite resin during polymerization contraction. Dycal was better adapted to the cavity floor than Prisma VLC Dycal. Disorganization of the resin-bonded Prisma VLC Dycal was minimal even after acid etching the enamel, sectioning and ultrasonic debridement. Dycal appeared to be more friable, and occasionally exhibited marked disorganization as a result of these procedures.     

Incorporation of anti-inflammatory agent into calcium hydroxide pulp capping material: an in vitro study of physical and mechanical properties

The aims of this study were to investigate the release of fluocinolone acetonide from an experimental pulp capping material containing fluocinolone acetonide (PCFA) and compare some physical and mechanical properties with Dycal(?). The PCFA is a hard-setting calcium hydroxide cement composed of 50 mmol/L fluocinolone acetonide. Conditioned media from the setting material was collected for determination of fluocinolone acetonide release by high performance liquid chromatography and pH measurement by pH meter. The setting time, compressive strength, disintegration, and acid soluble arsenic content were measured according to ISO 3107:2004. Dycal(?) was used as control. Fluocinolone acetonide could release at a range of suitable concentrations from PCFA. The pH, setting time, and acid soluble arsenic content of PCFA were significantly higher than those of Dycal(?). The compressive strength and disintegration of PCFA were comparable to control. PCFA may be considered as an alternative in pulp capping of inflamed dental pulp tissue.     

Newly developed resinous direct pulp capping agent containing calcium hydroxide (MTYA1-Ca)

AIM: The aim of this study was to evaluate a newly developed resin (MTYA1-Ca) for direct pulp capping. METHODOLOGY: The powder of MTY1-Ca is composed of 89.0% microfiller, 10.0% calcium hydroxide and 1.0% benzoyl peroxide and was mixed with liquid (67.5% triethyleneglycol dimethacrylate, 30.0% glyceryl methacrylate, 1.0% o-methacryloyl tyrosine amide, 1.0% dimethylaminoethylmethacrylate, and 0.5% camphorquinone). The shear bond, diametral tensile, bending and compressive strengths were measured. The alkaline activity of the elute dissolved from MTYA1-Ca was calculated. Cell viability by MTT assay and alkaline phosphatase (ALPase) activity were evaluated from dental pulp fibroblast reaction to the eluate dissolved from MTYA1-Ca. Histopathological studies of the response to exposed dental pulp of beagle dogs were completed with Dycal as a control. RESULTS: The physical properties of MTYA1-Ca were significantly superior to those of Dycal. It was impossible to measure these properties with Dycal because of poor physical properties. Both MTYA1-Ca and Dycal maintained high levels of alkaline activity (pH 10.96-12.20) over the 168-h duration of the study. Cell viability by MTT assay in the intact eluate of MTYA1-Ca was significantly higher than that of Dycal, whilst ALPase showed no difference between MTYA1-Ca and Dycal. A dentine bridge formed more slowly under MTYA1-Ca than under Dycal, but similar amounts had formed at 90 days. CONCLUSIONS: MTYA1-Ca has the potential to be used as a direct pulp capping material.     

Evaluation of lining materials and a new concept for lining: alpha-TCP cement or visible light curing calcium hydroxide composition in composite resin restoration

Histological studies on the effect of lining methods using a alpha-TCP (TC) and a VLC Dycal (LD) were reported previously. In this report, SEM and electron-probe microanalyzer observations were utilized to determine the effects of lining methods. SEM observations were made on longitudinal sections prepared by a freeze fracture method, using 30 vital dog teeth and 5 vital human teeth. In the LD group, several kinds of crystal growth were seen on surfaces of the material and dentinal wall. In the TC group, the exfoliated space area filled up with rod-shaped crystals. An electron-probe microanalyzer was employed to examine the crystal elements observed in the interface or the exfoliated space area. Our findings indicated that lining appeared to fill the gaps with crystal growth, block stimuli which result from bacterial invasion into the dentinal tubules, and reinforce the superficial dentinal zone.     

An in vitro comparison of the sealing ability of materials placed in lateral root perforations

The in vitro sealing ability of Tytin amalgam, Ketac-Silver, and Prisma VLC Dycal was compared. Roots of extracted teeth were perforated laterally. After the defects were repaired, the teeth were immersed in dye for 10 days and then sectioned, and the linear extent of dye penetration was measured. Statistical analysis showed that the Prisma VLC Dycal group exhibited significantly less dye penetration than the other two groups (p less than 0.01). No difference was found between the Tytin and Ketac-Silver groups.     

Anti-inflammatory and Mineralization Effects of ProRoot MTA and Endocem MTA in Studies of Human and Rat Dental Pulps In Vitro and In Vivo

Introduction

Few studies have reported direct pulp capping in inflamed pulp conditions. The purpose of this study was to investigate the in vitro and in vivo responses of dental pulp during direct pulp capping using various pulp capping materials in inflamed conditions.

TheraCal LC和Dycal两种盖髓剂用于乳牙和恒牙直接盖髓的疗效比较

目的 比较TheraCal LC和Dycal两种盖髓剂用于乳、恒牙直接盖髓术的临床疗效。方法 选择深龋意外露髓的乳牙180颗和恒牙243颗做直接盖髓术,乳、恒牙均按单双数就诊顺序采用半随机方法分为两组,乳牙TheraCal LC组81例患者（90颗牙）;乳牙Dycal组76例患者（90颗牙）。恒牙TheraCal LC组102例患者（122颗牙）;恒牙Dycal组109例患者（121颗牙）。术后12个月,比较两种材料的治疗成功率。结果 治疗12个月后,恒牙TheraCal LC组成功率为95.1%,恒牙Dycal组成功率为93.3%,两组之间差异无统计学意义（P>0.05）。乳牙TheraCal LC组成功率为87.7%,乳牙Dycal组成功率为46.9%,两组之间有显著差异（P<0.05）。结论 TheraCal LC盖髓剂更适合乳、恒牙的盖髓剂,乳牙的优势可能更为明显。     

A comparative histological analysis of human pulp following direct pulp capping with Propolis, mineral trioxide aggregate and Dycal

Background:  Permanent teeth pulp exposures have traditionally been treated with calcium hydroxide pulp capping. The aim of this study was to investigate the response of human pulp tissue which were mechanically exposed to a new material, Propolis and compare it with two existing and commonly used pulp capping agents (mineral trioxide aggregate and Dycal).
Methods:  Thirty-six intact human premolars were mechanically exposed. Teeth were divided into six groups of 6 teeth each and were capped with Propolis, mineral trioxide aggregate and Dycal. Final restoration was done with posterior composite resin using light cured glass ionomer cement as a liner. The teeth were then extracted on the 15th or the 45th day and processed for histological evaluation.
Results:  Differences in inflammatory response and dentine bridge formation of the exposed pulp to the three different materials were statistically calculated using chi-square test and were found to be non-significant. There was more pulp inflammation in teeth treated with Dycal than with Propolis and MTA on the 15th as well as on the 45th day. Propolis and MTA showed bridge formation in more teeth, and the bridges were in closer proximity to pulp capping material than teeth treated with Dycal on the 45th day.
Conclusions:  The response of pulps to Propolis as a pulp capping agent was comparable to MTA and Dycal.     

Leakage of chemical and light-cured basing materials

This study investigated the sealing properties of chemical and light-cured basing materials in dentin. Fifty extracted molars were selected and cleaned. Slot preparations with standard dimensions were made. The prepared cavities were filled with Cavitec, Life, Ketac-Bond, VLC Dycal, and Cavalite materials. Samples were immersed in 0.05% crystal violet solution for 2 hours. The samples were then embedded in clear casting resin, sectioned, and examined with a microscope. Results indicated that Cavalite and Ketac-Bond materials allow a greater degree of dye penetration that the three other materials. Cavitec, VLC Dycal, and Life materials were similar to each other in degree of dye penetration.     

Clinical results of potassium nitrate use in polycarboxylate cement for biological treatment of reversible pulpitis

To determine effectiveness of indirect pulp capping with 5% potassium nitrate in polycarboxylate cement for biological treatment of reversible pulpitis, a clinical study of 232 teeth with active caries lesions from 205 healthy patients aged from 16 to 40 years was performed. They were divided into 2 groups: the study group--140 teeth of 127 persons with 5% potassium nitrate in polycarboxylate cement (Carboxy Adhesor); control group--92 teeth of 78 persons with calcium-hydroxide cement (Dycal). Short-term clinical results showed better desensitizing effect and faster recovery to normal values of electric vitality in teeth treated by potassium nitrate in comparison with Dycal lining (p<0.001). Long-term follow-up (up to 2 years) showed good functional conditions, preserved vitality and x-ray status of the treated teeth.