Eugenol-free Zinc Oxide Research Articles

How can excess residual cement be reduced in implant-supported restorations?: An in vitro study.

The aim of this study was to investigate the effect of different cements and cementation techniques used in implant-supported restorations and the application of various vent modifications and extraoral replica techniques on the amount of overflowing cement in cemented systems. In this study, three different abutment designs were used as fully closed, occlusal vented, and occlusal + proximal vented. An extraoral replica was produced by milling the CAD/CAM ceramic block. The number of groups with and without replicas was determined as six (n = 10). For the cementation procedures, three different cements were tested: dual-cure resin, eugenol-free zinc oxide, and polycarboxylate cements. Cobalt-chromium superstructures to be cemented to the implant analog-abutment complex were produced by direct metal laser sintering method. Twenty-four hours after the cementation process, residual cement were measered with Micro-CT. In comparisons between groups, ANOVA test was used for normally distributed variables and Kruskall-Wallis H test was used for non-normally distributed variables at a significance level of p < 0.05. The difference in residual cement volumes between the groups in terms of both cementation techniques (whether or not to use an extraoral replica and different vent desings) and cement types was found to be statistically significant (p < 0.05). There was significantly less residual cement in all groups that used extraoral replicas than those that did not. As for the cement types, the most residual cement occurred in the resin cement. The use of extraoral replicas and vent designs on the abutment significantly reduces the amount of residual cement. Regardless of the cementation technique, the type of cement used affects the amount of excess cement. To reduce residual cement, both the type of cement and the cementation technique used must be considered.

Marginal Discrepancy of Cast Copings to Abutments with Three Different Luting Agents.

Aim The purpose of this study was to evaluate the MD (marginal discrepancy) on the calcinable copings in abutments for cemented prostheses with three luting agents. Methods Sixty-four analogs of CeraOne-type abutments (NACONIH code, Titanium Fix Implant Sytem SP, Brazil) were divided into four groups (n = 16). The copings were cast and placed on the CeraOne abutment analogs and cemented with eugenol-free zinc oxide (EfZO) (n = 16), with glass ionomer (GI) (n = 16), and with zinc phosphate (ZP) (n = 16), and as a control group, there were CeraOne plastic copings (NACOC code, Titanium Fix Implant Sytem SP, Brazil) (n = 16) which were not cemented with any material. After 24 hours, the MD of the four groups was measured. MD was evaluated using a stereoscopic microscope (Leica EZ4 W, Leica Microsystems, Germany) with an increase of ×100. MD was measured at four predetermined and equidistant sites with respect to the marginal line of the cast adaptation. The measurement was made from the distance between the free edge of the cast cylinder and the margin of preparation of the titanium abutment, with a level of statistical significance of p < 0.05. Results Of the three fixing agents, the ZP was found to have the highest MD (53.59 ± 14.21 μm); however, the lowest MD (41.72 ± 9.10 μm) was found in the GI group. These differences are statistically significant at p < 0.001. Conclusions In summary, according to our results, it was found that ZP cement showed the highest MD after cementation, followed by the glass ionomer, while EfZO showed the lowest MD.

Retrievability of implant-supported zirconia restorations cemented on zirconia abutments

Statement of problemRetrievability of implant-supported restorations is important. Data are lacking for cemented zirconia crowns on zirconia abutments. PurposeThe purpose of this in vitro study was to investigate the influence of different cements and marginal discrepancy on the retrievability of implant-supported zirconia crowns. Furthermore, the influence of thermocycling on retrievability was evaluated. Material and methodsThirty tapered Camlog zirconia abutments (6-degree taper, 6×4.3 mm) were used. Thirty zirconia crowns with 3 different marginal cementation discrepancies (70, 130, 190 μm) were fabricated by using computer-aided design and computer-aided manufacturing (CAD-CAM) technology. Five cements for interim or semidefinitive cementation were used: eugenol-free zinc oxide (Freegenol) and acrylurethane (ImProv) and 3 different composite resin cements (X-Pand Implant, Dyna Implant, Telio CS Cem Implant). Specimens underwent either 3-day storage in sodium chloride or thermocycling (10 000 cycles). Crowns were removed by using a universal testing machine (UTM) and a clinical removal device. Data were analyzed using 1-way ANOVA and the Scheffé test (α=.05). ResultsThermocycling decreased the retention force significantly (P<.001). Marginal discrepancy (70 to 190 μm) was not significantly influential on retrievability (P>.05). Therefore, groups were pooled according to the factor of marginal discrepancy. The mean retention force using the UTM after 3-day storage and thermocycling was as follows: Freegenol, 235 ±42 N (thermocycling, 29 ±9 N); Improv, 110 ±50 N (thermocycling, 35 ±38 N); Telio CS, 104 ±17 N (thermocycling, 6 ±10 N); Dyna implant, 61 ±17 N (thermocycling, 1 ±1 N); and X-Pand, 50 ±16 N (thermocycling, 2 ±2 N). ConclusionsRetention forces of the tested cements were significantly different and decreased considerably after thermocycling. Marginal cementation discrepancy between 70 and 190 μm did not influence retrievability.

Antibacterial property of eugenol and eugenol-free zinc oxide cements incorporated with various concentrations of sodium fluoride

Background: Restoring tooth by fixed partial dentures involves tooth reduction to reproduce the dental anatomy in the prosthesis. This process brings about the exposure of millions of dentinal tubules which serves as potential passageways for the diffusion and colonisation of bacteria. Aim: To evaluate and compare the antibacterial property of eugenol and eugenol-free zinc oxide cements incorporated with various concentrations of sodium fluoride. Materials and Methods: Circular specimens of zinc oxide eugenol (ZOE) and eugenol-free zinc oxide cements were prepared with and without incorporation of sodium fluoride at various concentrations. The antibacterial property of the cement specimens was evaluated against Streptococcus mutans using disc diffusion method. Zone of inhibition which was formed under anaerobic conditions after a period of 48 h was recorded. Results: The difference in antibacterial property of ZOE cements and eugenol-free zinc oxide cements containing sodium fluoride was statistically highly significant at all the concentrations of sodium fluoride. Eugenol-free zinc oxide did not show any antibacterial property at all. The different percentages of fluoride concentrations, that is, 1% and 2%, did not show significant difference statistically. Conclusion: Eugenol-free zinc oxide cement did not have any antibacterial effect with or without fluoride. Eugenol-containing zinc oxide cement with sodium fluoride had maximum antibacterial properties. Eugenol-containing zinc oxide cement exhibited antibacterial properties of its own.

Sealing ability of materials used as protective cervical barrier in internal tooth bleaching

The use of a protective cervical barrier (PCB) is very well established to perform a safe internal bleaching; however, there is still no consensus on which material has the best sealing ability. Objective: This in vitro study aimed to evaluate the apical and linear sealing of different PCB materials placed during internalbleaching. Material and methods: This study had two study factors: PCB positioning, divided at two levels (cement-enamel junction [CEJ] and 1mm above the cement enamel junction [CEJ+1]); and PCB material, divided at eight levels (resin composite [RC], glass ionomer cement [GIC], resin-modified glass ionomer cement liner [LRGIC], restorative resin-modified glass ionomer cement [RRGIC], zinc phosphate cement [ZPC], eugenol-free zinc oxide cement [ZOC],provisional filling resin [PFR] and gutta-percha as control [GUT]). Response variables were apical and linear sealing obtained through dye penetration and analyzed with a digital microscope. Data were subjected to two-way analysis of variance followed by Tukey test (p&lt;0.05). Results: The main factor for both apical and linear sealing was the type of material (p&lt;0.01), regardless of their position. RC and ZPC presented the worst sealing values (p&lt;0.05). The Spearmanrank correlation coefficient revealed a positive correlation between the apical and linear leakage. Conclusion: The results suggest that RC and ZPC must be avoided as a PCB during internal bleaching procedures.

Sealing ability of materials used as protective cervical barrier in internal tooth bleaching

The use of a protective cervical barrier (PCB) is very well established to perform a safe internal bleaching; however, there is still no consensus on which material has the best sealing ability. Objective: This in vitro study aimed to evaluate the apical and linear sealing of different PCB materials placed during internal bleaching. Material and methods: This study had two study factors: PCB positioning, divided at two levels (cement-enamel junction [CEJ] and 1mm above the cement enamel junction [CEJ+1]); and PCB material, divided at eight levels (resin composite [RC], glass ionomer cement [GIC], resin-modified glass ionomer cement liner [LRGIC], restorative resin-modified glass ionomer cement [RRGIC], zinc phosphate cement [ZPC], eugenol-free zinc oxide cement [ZOC], provisional filling resin [PFR] and gutta-percha as control [GUT]). Response variables were apical and linear sealing obtained through dye penetration and analyzed with a digital microscope. Data were subjected to two-way analysis of variance followed by Tukey test (p&lt;0.05). Results: The main factor for both apical and linear sealing was the type of material (p&lt;0.01) regardless of their position. RC and ZPC presented the worst sealing values (p&lt;0.05). The Spearman rank correlation coefficient revealed a positive correlation between the apical and linear leakage. Conclusion: The results suggest that RC and ZPC must be avoided as a PCB during internal bleaching procedures.

An In vitro Study to Evaluate the Effect of Eugenol-free and Eugenol-containing Temporary Cements on the Bond Strength of Resin Cement and Considering Time as a Factor.

Aims and Objectives:The aim of this study was to assess the outcome of eugenol-free and eugenol-containing cements on the bond strength of resin cement.Materials and Methods:Dentin was exposed in five groups of extracted teeth (20 specimens each). In Group 1, specimens were not given temporary cementation. In Groups 2 and 3, specimens were given temporary restoration fixed with eugenol-free temporary cement for 7 and 14 days, respectively. In Groups 4 and 5, specimens were given temporary restoration fixed with eugenol-containing temporary cement for 7 and 14 days, respectively. Permanent cementation was done for all groups after specified period of time. Shear bond strength testing of specimens was carried under universal testing machine. The data were analyzed by SPSS for Windows (version 14) statistical package (SPSS Inc., Chicago, IL, USA).Results:One-way analysis of variance test revealed that Group 1 specimens produced higher shear bond strength than Groups 2, 3, 4, 5 and the difference was statistically significant (P < 0.001). In Groups 2, 3, 4, and 5, no significant difference in shear bond strength was observed between provisional restoration with eugenol-containing zinc oxide cement and provisional restoration with eugenol-free zinc oxide cement (P = 0.095).Conclusion:The findings of this in vitro experiment lend no support to the common opinion that eugenol-containing cements should be avoided as temporary cement.

In Vitro Evaluation of Planktonic Growth on Experimental Cement-Retained Titanium Surfaces.

BackgroundThe purpose of this study was to compare the effects of selected cements, or their combination with titanium, on the growth of two periodontopathic bacteria: Prevotella intermedia (Pi) and Fusobacterium nucleatum (Fn).Material/MethodsThis study was comprised of several experimental groups: 1) Dental luting cements (glass ionomer cement, methacrylate-based resin cement, zinc-oxide eugenol cement, eugenol-free zinc oxide cement; 2) titanium discs; and 3) titanium combination cement discs. The disks were submerged in bacterial suspensions of either Fn or Pi. Planktonic bacterial growth within the test media was measured by determining the optical density of the cultures (OD600). Mean and standard deviations were calculated for planktonic growth from three separate experiments.ResultsIntergroup comparison of all experimental groups revealed increased growth of Pi associated with cement-titanium specimens in comparison with cement specimens. Regarding the comparison of all groups for Fn, there was an increased amount of bacterial growth in cement-titanium specimens although the increase was not statistically significant.ConclusionsThe combination of cement with titanium may exacerbate the bacterial growth capacity of Pi and Fn in contrast to their sole effect.

Removal force of cast copings to abutments with three luting agents

Purpose: The purpose of this study was to evaluate the removal force of cast copings over abutments cemented with 3 dental cements. Methods: The experiment used 36 abutments divided into six groups (n = 6) Cast copings with CeraOne cemented with zinc oxide-free eugenol; with glass ionomer; with zinc phosphate and solid 5-mm-high abutments cemented with the same cements wax loops (3 mm in diameter) were made and added to the occlusal surface to allow for tensile testing, and the copings were cast in cobalt-chromium alloy using the lost wax method. The copings were sandblasted with 50-μm aluminum oxide particles to prevent irregularities and cleaned with acetone. The copings were cemented with a 49-N load for 10 min. Subsequently, they were separated with a universal testing machine (Tensometer; Monsanto) at a rate of 5 mm/min until the detachment. The effects of cement and abutment type were evaluated using the means and standard deviations of the loads and were analyzed with ANOVA and the Tukey test (α =0.05). Results: The abutments with a height of 5.5 mm had a statistically significant (P < 0.001) higher tensile strength with a mean of 84.60 N (±8.82) than that of the CeraOne abutments with an average of 36.09 N (±11.66) when cemented with zinc oxide. Conclusions: We conclude that the type of cement and abutment can significantly influence the retention of implant-supported crowns. The results do not suggest that any one type of cement is better than another, but they rank cements in order of retention capacity. Zinc phosphate provided the greatest retention while the eugenol-free zinc oxide provided the least (P < 0.001).

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.

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. To determine how oral bacteria associated with peri-implant disease grow in the presence of implant cements. 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. 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. 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.

Effect of modifying the screw access channels of zirconia implant abutment on the cement flow pattern and retention of zirconia restorations

The effect of managing the screw access channels of zirconia implant abutments in the esthetic zone has not been extensively evaluated. The purpose of this study was to determine the effect of an insert placed within the screw access channel of an anterior zirconia implant abutment on the amount of cement retained within the restoration-abutment system and on the dislodging force. Thirty-six paired zirconia abutments and restorations were fabricated by computer-aided design and computer-aided manufacturing and were divided into 3 groups: open abutment, with the screw access channel unfilled; closed abutment, with the screw access channel sealed; and insert abutment, with a thin, tubular metal insert projection continuous with the screw head and placed into the abutment screw access channel. The restorations were cemented to the abutments with preweighed eugenol-free zinc oxide cement (TempBond NE). Excess cement was removed, and the weight of the cement that remained in the restoration-abutment system was measured. Vertical tensile dislodging forces were recorded at a crosshead speed of 5 mm/min after incubation in a 37°C water bath for 24 hours. The specimens were examined for the cement flow pattern into the screw access channel after dislodgement. Data were analyzed with ANOVA, followed by multiple comparisons by using the Tukey honestly significant difference test (α = .05). The mean (standard deviation) of retentive force values ranged from 108.1 ± 29.9 N to 148.3 ± 21.0 N. The retentive force values differed significantly between the insert abutment and both the open abutment (P < .05) and closed abutment groups (P < .01). Distinct patterns of cement failure were noted. The weight of the cement that remained in the system differed significantly, with both open abutment and insert abutment being greater than closed abutment (P < .05). Modifying the internal configuration of the screw access channel of an esthetic zirconia implant abutment with a metal insert significantly affected both the cement retained within the abutment itself and the retention capabilities of the zirconia restoration cemented with TempBond NE cement.

Comparison of 3 Luting Agents on Retention of Implant-Supported Crowns on 2 Different Abutments

For fixed prostheses, retention is one of the most important factors for clinical success. It is unknown whether grooves that increase surface area of implant abutment while retaining the diameter and wall height provide greater uniaxial retention force. The purpose of this study was to determine the retention of 3 different cements on 2 implant abutments with different surface configurations. Thirty samples on 2 different abutments (a total of 60 crowns) with different margin and axial walls configuration and surface area were used. Metal crowns were fabricated on the abutment and cemented with 3 different (zinc-phosphate [ZP], glass ionomer [GI], or eugenol-free zinc oxide [ZO]) cements. After cementation, implant-abutment-casting assemblies were thermal cycled 1000 times with 1-minute dwell-time between 5°C and 55°C then subjected to tensile test with universal testing machine until decementation occurred. The mean force required to dislodge castings from abutment was determined. The luting agents influenced retention of castings on implant abutments, whereas different surface configurations and total surface area of the abutments did not influence the uniaxial retention forces. Among the cements tested, ZP exhibited higher values of retention, followed by GI and eugenol-free ZO. The increase in surface area of abutment did not result in improved retention. The present results suggest using ZP rather than GI and eugenol-free ZO in implant-supported crowns to provide higher retention.

Retrievability of implant‐retained crowns following cementation

The purpose of this study was to assess the retrievability of cemented implant crowns using two different removal devices. The influence of five cement types and two cement application techniques was evaluated. Forty copings were cast from a CoCr alloy for 40 tapered titanium abutments (5 degrees taper, 4.3 mm diameter, 6 mm height, Camlog, Germany). Twenty copings were modeled as single crowns, whereas 20 copings were modeled with an extension to simulate fixed partial dentures (FPDs). Before cementation, the inner surfaces of the copings were air-abraded (50 mum Al(2)O(3) particles at 2.5 bars), while the abutments were used as delivered with machined surfaces. Copings were cemented with eugenol-free zinc oxide (Freegenol), zinc phosphate (Harvard), glass ionomer (Ketac Cem), polycarboxylate (Durelon) and so-called self-adhesive resin (RelyX Unicem) cement. Cement was applied in a thin film band of 1 or 3 mm to the cervical margin of the inner surface of the copings, respectively. After cementation, specimens were stored in saline solution for 24 h. The Coronaflex and a standardized custom-made removal device were used to remove the copings from the abutments. Using the same cement, no statistically significant influence with regard to the type of restoration (crown/FDP), cement application mode and device was detected (P>0.05). Therefore, data of specimens cemented with the same cement were pooled. Median attempts to remove the copings were: zinc oxide: 3, self-adhesive resin: 3, zinc phosphate: 5, glass ionomer: 16 and polycarboxylate: 58. Four levels of significance (P<0.0001) were found: (1) zinc oxide/self-adhesive resin; (2) zinc phosphate; (3) glass ionomer; and (4) polycarboxylate. Zinc phosphate and glass ionomer cement might be suitable for a so-called 'semipermanent' (=retrievable) cementation, while polycarboxylate seems to provide the most durable cementation.

The Comparative Radiopacity of Fuji IX-GP, an Intermediate Restorative Material

The radiopacity of intermediate restorative materials should be sufficient to enable the clinician to distinguish the material from normal and decalcified tooth structure. The purpose of this study was to determine the relative radiopacities of intermediate restorative materials, including a newly introduced high-viscosity, self-cured, condensable glass ionomer material. Radiographs were made of six intermediate restorative materials: two reinforced zinc oxide-eugenol materials (IRM and Zinroc), a conventional glass ionomer material (Ketac-fil), a synthetic resin material (Cavit), a eugenol-free zinc oxide material (Tempit), and a new, general-purpose, condensable glass ionomer material (Fuji IX-GP). Optical density was measured using a densitometer. The optical density of dentin and enamel were used for radiographic comparison. Statistical analysis revealed significant differences among materials: Cavit = IRM = Tempit > Zinroc = Fuji IX-GP > Ketac-fil = enamel > dentin (where > indicates a statistical difference at p < or = 0.05). Although not as radiopaque as some other intermediate materials tested, the radiopacity of Fuji IX-GP appears sufficient to aid diagnosis.

Accuracy and dimensional stability of four interocclusal recording materials

Four materials, zinc oxide-eugenol paste, eugenol-free-zinc oxide paste, a silicone, and polyether jaw relations registration material were studied in a controlled laboratory environment to determine their accuracy and stability in intervals over a 1-week period. The results are as follows: 1. The eugenol-free zinc-oxide paste was the only material which exhibited no statistically significant difference between the die scribes and those of the sample. 2. The setting reaction of the eugenol-free-zinc oxide paste was a saponification reaction, resulting in the production of an insoluble soap. 3. With polyether, silicone, and zinc oxide-eugenol paste, there was a statistical difference between the die and the respective samples at the immediate reading and throughout the experiment. Polyether showed the least difference, and zinc oxide-eugenol paste the greatest.