Comparative Evaluation of Antibacterial Effect of Dental Luting Cements on Streptococcus mutans and Lactobacillus acidophilus: An In vitro Study.

INTRODUCTION: This study aimed at evaluating and comparing the antibacterial activity of six types of dental luting cements on Streptococcus mutans and Lactobacillus acidophilus using the agar diffusion test (ADT) and the direct-contact test (DCT). The antibacterial activity in ADT was measured based on the diameter of the zone of inhibition formed, whereas in DCT the density of the bacterial suspension was measured. The lower the density of the suspension, the more antibacterial activity the cement possesses. MATERIALS AND METHODS: Agar diffusion test was carried out on the bacteria. After an incubation period of 24 hours, the plates were checked for the presence of zone of inhibition. In DCT the cement was mixed and applied. Once the cement was set, bacterial suspension and brain-heart infusion medium was poured and incubated for 24 hours. After 24 hours, the plate was placed in the enzyme-linked immunosorbent assay plate reader, which measured the optical density of the fluid. The first set of data was recorded approximately 1 hour after incubation. Overall, three sets of data were recorded. Additional experiments were performed on set test materials that were allowed to age for 24 hours, 1 week, 1, 3, and 6 months. RESULTS: When using ADT only two cements zinc oxide eugenol (ZOE) and zinc polycarboxylate (ZPC) cement showed antibacterial activity against the test organisms. When using DCT, all cements showed some amount of antibacterial activity. Zinc oxide eugenol and ZPC cement showed highest amount of antibacterial activity against S. mutans and L. acidophilus respectively. CONCLUSION: Within the limitations of study, ZOE cement and ZPC cement were most effective against the tested microorganisms followed by the newer resin cement. The glass ionomer cement was the weakest of all. CLINICAL SIGNIFICANCE: Patients with high caries index can be treated more effectively using the abovementioned cements.

The Interaction of Implant Luting Cements and Oral Bacteria Linked to Peri-Implant Disease: An In Vitro Analysis of Planktonic and Biofilm Growth--A Preliminary Study.

BACKGROUND: There is little consensus on the most appropriate cement to use when restoring a cement-retained, implant-supported restoration. One consideration should be the interaction of pathogenic oral bacteria with restorative cements. PURPOSE: To determine how oral bacteria associated with peri-implant disease grow in the presence of implant cements. MATERIALS AND METHODS: Five test cements with varying composition (zinc oxide-eugenol [TBO], eugenol-free zinc oxide [TBNE], zinc orthophosphate [FL], and two resin cements [PIC and ML]) were used to fabricate specimen disks. The disks were submerged in bacterial suspensions of either Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, or Porphyromonas gingivalis. Planktonic bacterial growth within the test media was measured by determining the optical density of the cultures (OD600 ). Positive controls (media and bacteria without cement disks) and negative controls (media alone) were similarly evaluated. The mean and standard deviations (SD) were calculated for planktonic growth from three separate experiments. ANOVA statistical analysis with post hoc Tukey tests was performed where differences existed (p < .05). Selected cement disks (TBO and ML) were further examined for bacterial biofilm growth. Surface bacteria were removed and grown on agar media, and colony-forming units (CFUs) were quantified. RESULTS: Planktonic growth for both A. actinomycetemcomitans and P. gingivalis was significantly inhibited (p < .05) when grown in the presence of cement disks consisting of TBNE, PIC, FL, and TBO. In contrast, neither of these bacteria displayed growth inhibition in the presence of ML cement disks. F. nucleatum growth was also significantly inhibited by PIC, FL. and TBO (p < .05), but not by ML and TBNE cement disks. CFU counts for the biofilm study for TBO gave minimal and, in some instances, no bacterial adherence and growth, in contrast to ML, which supported substantially greater bacterial biofilm growth. CONCLUSION: Cements display differing abilities to inhibit both planktonic and biofilm bacterial growth. Cements with the ability to reduce planktonic or biofilm growth of the test bacteria may be advantageous in reducing peri-implant disease. Understanding the microbial growth-inhibiting characteristics of different cement types should be considered important in the selection criteria.

Antibacterial potential of contemporary dental luting cements.

The aims of this investigation were to evaluate the antibacterial activities of different types of dental luting cements and to compare antibacterial action during and after setting. Agar diffusion testing was used to evaluate the antibacterial properties of seven types of dental luting cements (glass ionomer cements (GICs), resin modified GICs, resin composite, zinc oxide eugenol, zinc oxide non-eugenol, zinc phosphate, zinc polycarboxylate cements) on Streptococcus mutans bacteria. Instantly mixed zinc phosphate cements showed the strongest antibacterial activity in contrast to the non-eugenol, eugenol and resin cements that did not show any antibacterial effects. Non-hardened glass ionomer, resin modified and zinc polycarboxylate cements exhibited moderate antibacterial action. Hardened cements showed weaker antibacterial activities, than those ones applied right after mixing.

The effect of luting agents on the retention of dental implant-supported crowns.

BACKGROUND: This study was designed to evaluate the retentive strength of 7 different luting agents on cement-retained implant abutment/analog assemblies. METHODS: Fifty-six Steri-Oss implant abutment/analog assemblies and cast superstructures were randomly divided into 7 groups: definitive cements included zinc phosphate cement, Advance, All-Bond 2, Panavia F, and Durelon, while provisional cements included Temp Bond and ImProv. After the superstructures were cemented onto the implant abutments, the specimens were subjected to 100,000 cycles on a chewing machine (75 N) and 1000 cycles on a thermocycling machine (0-55 degrees C). A universal testing machine was used to test the cement failure load values for each specimen. One-way ANOVA and Duncan's multiple-range analysis were used to determine the effects of luting agents on cement failure load values. RESULTS: The following values for the mean and standard deviation of cement failure loads for each group were obtained: zinc phosphate, 1.225 +/- 0.229 MPa; Advance, 1.205 +/- 0.197 MPa; All Bond 2, 1.752 +/- 0.211 MPa; Panavia F, 1.679 +/- 0.176 MPa; Durelon, 0.535 +/- 0.161 MPa; Temp Bond, 0.274 +/- 0.079 MPa; and ImProv, 0.319 +/- 0.107 MPa. CONCLUSIONS: There were significant differences in cement failure loads among the various cements tested. Values significantly differed among 4 groups consisting of All-Bond 2 and Panavia F resin cements, zinc phosphate cement and Advance hybrid ionomer cement, Durelon carboxylate cement, and ImProv and Temp Bond provisional cements (p < 0.0001). All-Bond 2 and Panavia F resin cements had statistically significantly higher values for cement failure loads compared to the other 5 types of cement.

Fluid movement across the resin-dentin interface during and after bonding.

This study evaluated the extent of water penetration through resin-dentin interfaces before and after being sealed with adhesives. Four adhesive resin systems (2 total-etch adhesives and 2 self-etching primer adhesives) were used in this study. Dentin disks were placed in a split-chamber device, and in situ fluid movement across dentin was measured, with and without physiological pressure, during bonding procedures or 24 hrs after bonding. The fluid movement across dentin occurs via dentin tubules after acid-etching. Large outward or inward fluid shifts across dentin were observed during air-drying and light-curing for resin application. The amount of fluid movement across resin-bonded dentin when total-etch adhesives were used was significantly greater than that with self-etching adhesives. The milder acid-etching effects of self-etching primers may retain hybridized smear plugs within the tubules that reduce outward fluid flow, resulting in superior dentin sealing.

Ion release from copper phosphate cement and influence on Streptococcus mutans growth in vitro: a comparative study.

The aim of this study was to compare the effects of a black copper cement (BCC), an established restorative material (a conventional glass ionomer cement) and two temporary restorative materials (a zinc phosphate and a zinc polycarboxylate cement) on the growth of Streptococcus mutans in vitro, and to correlate bacterial growth with ion release from each material. Test specimens were eluted in either 0.1 M lactic acid, pH 4, or 0.1 M sodium chloride, pH 7. At 2 days, 7 days, 28 days and 6 months, eluates were inoculated with S. mutans and bacterial growth was recorded. Metal ion (Cu(2+), Zn(2+ )and Mg(2+)) and fluoride release were measured. At most immersion times, the different materials had a statistically significant inhibitory effect on bacterial growth compared to the respective control, at both pH levels. The inhibitory effect decreased with time and in most cases was associated with high levels of ion release at the beginning of the experimental period, followed by significantly lower levels. For BCC, there were statistically significant relationships between the median rates of growth of S. mutans in the presence of BCC eluates and the median values for release of copper and zinc, although not magnesium. Of the different materials, BCC demonstrated greatest antibacterial activity.

[Effect of physical and chemical factors on Macaca Mulatta's pulp and change of the collagen in pulp].

OBJECTIVE: To investigate the change of pulp and its collagen to outside stimuli. METHODS: 51 permanent teeth from 10 adult healthy Macaca Mulatta's monkeys were chosen as experimental teeth. 39 of them were prepared Class V cavities. The teeth were divided into two groups, one was filled with zinc phosphate cement and another group with zinc oxide eugenol. A blank control group of 12 teeth was set at the same time. Just after the operation, 3 d, 7 d, 1 month and 3 months later, the animals were executed. Histologic changes were evaluated by means of HE and collagen staining method. RESULTS: Local inflammation was the major representation in the pulps of the zinc phosphate cement group from 7 d to 3 months after operation. The percentage of collagen decrease dropped sharply, and there was no inflammation cells infiltration in the pulps of zinc oxide eugenol group from 1 to 3 months after operation. By means of collagen staining method, the morphological characters, distribution and the change of pulpal collagen during a certain pathologic process were clearly represented in histologic slices. The change of collagen appeared earlier than the inflammation cells infiltration. CONCLUSIONS: Zinc phosphate cement can lead to medium inflammation of the pulp. The change of collagen appears earlier than that of WBC, which can be used as a sensitive indicator.

Avaliaçäo do efeito de recimentaçöes sucessivas de coroas totais no desajuste marginal, retençäo friccional e retençäo final com três agentes cimentantes / Effect evaluation of consecutive recementations on marginal misfit, friccional retention and final retention of full crowns with three luting agents

Trinta dentes molares humanos recém-extraídos foram preparados para a confecçäo de infra-estruturas metalocerâmicas com o objetivo de avaliar o efeito de recimentaçöes sucessivas no desajuste marginal, retençäo friccional e retençäo final com três agentes cimentantes. Como parâmetro para as leituras de desajuste marginal, restauraçöes de amálgama de prata foram previamente realizadas nas raízes dos dentes em quatro pontos equidistantes nas faces vestibular, lingual, mesial e distal e posteriormente traçadas com uma lâmina de bisturi, duas linhas em cruz sobre as mesmas. Outras quatro cruzes foram demarcadas a ñ 1,5mm das margens das infra-estruturas. Após a confecçäo das peças fundidas, as amostras foram divididas em três grupos de dez, criando-se estes com médias equivalentes, tendo como base a retençäo friccional inicial. As amostras do Grupo 1 foram cimentadas com fosfato de zinco, as do Grupo 2 com ionômero de vidro modificado e as do Grupo 3 com resinoso. As medidas de desajustes das infra-estruturas foram realizadas com auxílio de microscópio óptico comparador e os valores médios foram: 177µm negativos para o Grupo 1, 100µm negativos para o Grupo 2 e 120µm para o Grupo 3. Estes valores de desajustes foram submetidos à análise de variância a dois critérios, demonstrando haver diferença significante entre os resultados. Baseado nisto, concluiu-se que houve melhor ajuste das infra-estruturas com as sucessivas recimentaçöes. Os testes de resistência à remoçäo por traçäo das infra-estruturas em relaçäo aos dentes preparados mostraram as seguintes variaçöes de valores de acordo com cada grupo de estudo: Grupo 1 de 774.0 a 137.6gf, Grupo 2: de 774.6 a 139.1gf e o Grupo 3: de 770.1 a 61.2gf. Os valores foram submetidos ao teste estatístico já citado e também houve uma diferença significante dos resultados...

Antibacterial properties of current orthodontic band cements.

PURPOSE: Manufacturers commonly provide information on the physical properties of dental materials, but information on their antibacterial properties is often missing. This study determined the antibacterial properties of four currently used orthodontic band cements against three different strains of Streptococcus mutans. METHODS: The cements utilized were Durelon, Ketac, Mizzy Zinc Phosphate, and Band-Lok, a recently introduced, resin-based, dual-cure glass ionomer cement. Disk diffusion assay methodology was used to test for zones of bacterial inhibition around cement samples. Zones of inhibition were measured in millimeters using an electronic caliper. In addition to cured cement plugs and freshly mixed cement samples, a new variation, in the form of a cement plug surrounding a stainless-steel band, was tested. Twelve combinations resulted from the four cement types and three forms. RESULTS: Of the variables studied, the mix forms of Durelon, Ketac, and Mizzy Zinc Phosphate cement showed the greatest bacterial inhibition (Kruskal-Wallis, P < 0.05). Among the cements tested, Mizzy Zinc Phosphate showed the largest zones of inhibition, with Durelon and Ketac having comparable zones of inhibition (Kruskal-Wallis, P < 0.05). Band-Lok did not exhibit an inhibitory effect against any of the three strains of S. mutans tested. CONCLUSION: A "containment effect" of no bacterial inhibition was observed in the cement samples surrounded by the stainless-steel band material.

[The effect of bonded and nonbonded posts on the fracture resistance of dentin]. / Die effek van gebonde en ongebonde stiwwe op die fraktuurweerstand van dentien.

This in vitro study determined the effect of bonded and non-bonded cast, serrated, tin plated, parallel gold posts on the fracture resistance of surrounding dentine walls. Specimens were divided into two groups. One group's posts were luted with zinc phosphate cement and the other group's posts were tin-plated and adhesively bonded with an adhesive resin cement. Three different dentine wall thicknesses, namely 0.5 mm, 0.75 mm and 1.0 mm were prepared, subdividing the specimens of each main group into three subgroups. Specimens were subjected to a 50 degrees oblique force. The force required to fracture the dentinal walls was registered. There was no statistically significant differences in the fracture resistance of dentine with the two different cements or of the different dentine wall thicknesses.

Biocompatibility of various dental materials: pulp healing with a surface seal.

Class V cavities with mechanical exposures were prepared in 178 teeth of seven monkeys to observe the temporal healing of exposed pulps in direct contact with various dental materials, with or without a biologic seal of zinc-oxide eugenol cement against microleakage. Thirty pulps were direct capped as calcium hydroxide controls. The remaining 148 exposures were direct capped, 41 with silicate, 39 with zinc phosphate, 33 with amalgam, and 35 with an auto-cured composite. Sixty-four were restored to their cavosurface margin with their respective material and 84 were sealed to the covosurface margin with zinc-oxide eugenol cement. Tissues were obtained by perfusion fixation at intervals of 35, 21, 14, 10, 5, and 3 days, and then processed and evaluated. The results of this study demonstrated that exposed dental pulps possess an inherent healing capacity, allowing cell reorganization and dentin bridge formation when adequately sealed with zinc-oxide eugenol cement to prevent bacterial microleakage.

Microleakage through dentin after crown cementation.

This study investigated the relationship between type of luting cement for artificial crowns and microleakage through dentinal tubules. Standardized preparations were made on intact human premolars, and crowns were made in a base metal alloy using conventional techniques. The castings were randomly assigned to the following luting agent groups: zinc phosphate (ZP), polycarboxylate (PC), glass ionomer (GI), phosphate ester composite resin (GMA/PE), and a composite resin with a NPG-GMA dentin bonding agent (GMA/NPG). Then they were cemented in a standardized manner. The specimens were artificially aged, stained, sectioned, and microleakage occurred through dentinal tubules toward the pulp measured. The rank in order from least to most (best to worst) leakage was GMA/NPG, GI, GMA/PE, PC, and ZP. Material GMA/NPG recorded significantly less leakage than all other materials. Therefore, the results of this study suggest that material GMA/NPG may reduce pulpal sensitivity and pathosis.

Evaluation and control of post-cementation pulpal sensitivity: zinc phosphate and glass ionomer luting cements.

Many studies have documented pulpal sensitivity after crown cementation, but none have determined its cause. By controlling technique variables in a large-scale clinical trial, the authors evaluated the contribution of zinc phosphate and glass ionomer luting cements in causing pulpal sensitivity or necrosis.

Antibacterial properties of eight dental cements.

The antibacterial action of a light-cured glass polyalkenoate Vitrebond and an adhesive resin luting agent Panavia Ex was investigated and compared with six previously tested dental cements. The bacterial cultures used were six strains of Streptococcus mutans, six of Streptococcus sanguis and six cultures of carious debris from carious lesions. A modification of the agar diffusion method was used to test the antibacterial action of freshly mixed cements. In addition the cements were allowed to set and their antimicrobial action was tested by incubation for 5 days in sucrose broth inoculated with the test cultures. All the freshly mixed materials had an antibacterial action. A two-way analysis of variance and Tukey-Student range analysis showed that Vitrebond had a significantly greater zone of inhibition than Aquacem, IRM, Dycal, Dycal VLC, Ceramco and GC Elite (P = 0.001). Freshly mixed Panavia Ex exhibited minimal antibacterial action. After 5 days the antibacterial properties of all the cements were reduced.

Pulpal healing and dentinal bridge formation in an acidic environment.

This study was designed to observe the healing and bridging capacity of mechanically exposed pulps that were capped with silicate or zinc phosphate cements and biologically sealed with zinc oxide-eugenol cement to exclude bacteria. In six monkeys, Class V facial cavities with pulpal exposures were randomly distributed throughout 105 teeth, of which 80 were directly capped, 40 with silicate cement and 40 with zinc phosphate cement. Twenty of each group were filled to the cavosurface margin with the respective cement and 20 were surface sealed to the cavosurface margin with zinc oxide-eugenol cement. The remaining 25 exposures were capped with calcium hydroxide and amalgam as controls. Tissues were obtained by perfusion fixation after intervals of 21, 14, 10, 5 and 3 days. The 25 pulps capped with calcium hydroxide showed cell migration and organization at 5 days and dentinal matrix deposition at 10 days. At 3 and 5 days, all exposures in the experimental groups showed clot resolution. At 10 days, fibroblasts had stratified against the cement interface. At 14 days, pulps in both experimental groups showed new dentinal bridge formation directly adjacent to the acidic cements. The 21-day experimentally capped and sealed pulps presented healing similar to the controls. This study indicates that acidic components of silicate and Zinc phosphate cements are not directly responsible for pulpal inflammation or necrosis. The exposed dental pulp possesses an inherent healing capacity for cell reorganization and dentinal bridge formation when a bacterial seal is provided.

[Antimicrobial activity of orthodontic band cements]. / Actividad antimicrobiana de materiales para cementación de bandas en ortodoncia.

The prevalence of enamel decalcification and caries beneath orthodontic bands, has indicated the need for a new enamel binding adhesive orthodontic cement. The purpose of this study was to evaluate the antimicrobial activity, in vitro, on Streptococcus mutans and Lactobacillus, acidophillus, of three materials used to cements the orthodontic bands. The cements studied were: Zinc phosphate cement, Glass-ionomer cement, and Policarboxylate cement. Thirty petri plates were seeded with S. mutans, and thirty with L. acidophillus; on each plate three pellet were placed, one of each cement studied. Petri plates were incubated under microaerophilic conditions at 37 C, and checked at 72 hrs. for Streptococcus, mutans, and four days for Lactobacillus acidophillus to evaluate the inhibition zone. The results were tabulated for each material. It was demonstrated that exists important variations in the antimicrobial properties of the materials studied, as in the microbial sensitivity to these cements.

[Materials properties of zinc phosphate cements after delayed setting on refrigerated slabs]. / Werkstoffeigenschaften von Zinkphosphatzementen nach verzögertem Abbinden auf gekühlten Platten.

Two of the zinc phosphate cements commonly used in orthodontics were mixed, with special attention being paid to the longest possible working time, and examined by scientific methods. The results showed that mixing should generally be carried out on frozen slabs (-18 degrees C to -24 degrees C) and for not longer than 5 min. If a maximum compressive strength is required, mixing should be done at refrigerator temperature (+4 degrees C to +8 degrees C) for no more than 1.5 min by accepting a shorter working time. Neither cement shows any notable physicochemical differences, as regards the material.