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PubMedDate not supplied

Retention forces and seating discrepancies of implant-retained castings after cementation.

PURPOSE: The purpose of this in vitro study was to evaluate the influence of cement type and application technique on seating discrepancies and retention forces of noble alloy castings cemented on titanium abutments. MATERIALS AND METHODS: Eugenol-free zinc oxide (Freegenol), zinc phosphate (Harvard), glass ionomer (KetacCem), polycarboxylate (Durelon), and self-adhesive resin (RelyX Unicem) cements were used. The inner surfaces of the castings were either completely coated or half-coated with cement. Abutments were used as delivered with a machined surface for the first part of the study. Groups of 8 castings were cemented in both ways. For the second part of the study, the abutments were air-abraded (aluminum oxide, 50 microm particle size), and groups of 8 completely coated castings were cemented with all cements. Marginal discrepancies were measured before and immediately after cementation. Tensile tests were conducted to measure the retention forces. Statistical analysis was performed with pair-wise comparison using the Wilcoxon rank sum test modified by Bonferroni-Holm. RESULTS: Change in seating discrepancies did not differ significantly among the different application techniques. The median retention forces for completely-coated castings were 177 N for eugenol-free zinc oxide, 346 N for zinc phosphate, 469 N for glass ionomer, 813 N for polycarboxylate, and 653 N for self-adhesive resin. With respect to retention force, 3 significantly different groups (P < .05) were identified: (1) zinc oxide, (2) zinc phosphate/glass ionomer, and (3) polycarboxylate/self-adhesive resin. No differences in retention between the 2 coating techniques were found for any cement. However, air abrading the abutments resulted in increased retention of the castings for some of the cements. CONCLUSIONS: Half-coating of the restorations with cements did not result in reduced retention values compared to the complete coating technique, but air abrasion resulted in increased retention with some cements.

Air Abrasion, Dental↗
PubMed1995

Reinforcement of bone cement around prostheses by pre-coated wire coil: a finite element model study.

The longevity of cemented total joint replacements, namely total hip arthroplasty (THA), depends on the integrity of the cement per se and interfaces of the metallic stem-cement and bone-cement, and stress/stress transmission and its distribution. A simple coil made of stainless steel wire was placed around a tapered stem in a simulated cement mantle to counteract the radial- and hoop-stresses created by the stem loading. Two-dimensional axisymmetric finite element analysis was performed to elucidate the level of the stress and its distribution with and without the wire coil. The results suggest that the peak stresses distributed throughout the cement may be reduced by more than one half, via the incorporation of a wire coil, confirming the mechanical test results, which showed an average fracture load of 3.70 +/- 1.13 kN for pure bone cement control and 9.02 +/- 1.54 kN for the wire coil reinforced specimens. These results indicate that the reinforcement of the cement mantle with a wire coil in the distal end of the hip stem prosthesis could reduce the hoop-stresses, which may results in reduced stresses in the bone and cement interface. Consequently, loosening of the interfaces of the bone-cement and cement-stem could be reduced due to the enhanced fatigue life of the bone cement mantle with favorable stress distribution at the distal tip of the stem.

Biomechanical Phenomena↗
PubMedDate not supplied

Comparative study of heat release of various cement base materials during their setting.

An ideal cement base material in order to protect the pulpal tissue from several external irritations (microbial, mechanical, thermal, galvanic and osmotic irritations) must present the following requirements: to attach or bond to the residual dentin, to be biocompatible, to present suitable physicomechanical, antimicrobial and optical properties, to be color stable, easy to use and rapid to set. Thermal phenomena developed during the mixing and setting are a factor influencing the biocompatibility properties of these materials. Cement base materials are used under various types of filling materials (amalgams, composite resins, gold and porcelain inlays) and are placed in contact with the dentin that contains exposed dentinal tubules. The purpose of this study was to investigate the possible exothermic reaction of these materials and to measure the developing temperatures for a time period from their mixing up to the completion of their setting. We studied the following types of cement base materials: a) Zinc oxide eugenol cement, b) Zinc phosphate cement, c) Zinc polycarboxylate cement and d) Glass ionomer cement both light- and self-cured. From the obtained results we observed that ZOE cements developed the lowest temperatures ranging from 32.8 degrees C to 37 degrees C, while Zinc phosphate cements developed the highest temperatures ranging from 44.4 degrees C to 52 degrees C. The other two types of materials Zinc polycarboxylate and Glass ionomer cements developed biocompatible temperatures ranging from 38 degrees C to 40.8 degrees C, which usually do not cause deteriorations and harms to the pulp. We concluded that the ZOE cements presented the best thermal behaviour followed by Zinc polycarboxylate and Glass ionomer cements. Hence, these materials can be safely used without causing any pulpal response.

Biocompatible Materials↗
PubMed1997

Fixation of the acetabular component. The case for cement.

The long-term success rate of cemented sockets in total hip arthroplasty has been well documented in patients who are 60 years of age and older and who have had a followup of as many as 16 years. The failures with cemented sockets have been observed in young patients, patients with poor bone stock (rheumatoid and dysplastic hips) with metal backed components, and in revision surgery with loss of acetabular bone. Ranawat et al have shown that most mechanical failures of cemented socket fixation within 10 years of primary operation is attributable to failure to achieve a good fixation initially of the cement and bone. Volumetric wear of the polyethylene of a cemented socket against a 22- or 28-mm femoral head is compared with the metal backed cemented and noncemented cups. The increase in volumetric polyethylene particles with metal backed cemented sockets and noncemented sockets will induce histiocytic response. The mechanism of histiocytic invasion should be similar for cemented all polyethylene sockets and noncemented sockets. It manifests itself in the cemented socket as global radiolucency when the socket is loose and as osteolysis when it is well fixed for noncemented and cemented sockets. If the number of particles coming out in a noncemented and hybrid total hip replacement are greater, osteolysis would be expected to increase with longer followup. The technique of cemented polyethylene sockets requires organization of the surgical team and hypotensive epidural anesthesia. Under these conditions the procedure is very reproducible. As far as cost is concerned, the all polyethylene socket is significantly less expensive. It seems that cemented total hip replacement is most suitable and perhaps is the right kind of operation for treating osteoarthritis of the hip for patients who are 60 years of age and older because the procedure is reproducible, the quality of arthroplasty is excellent, and it is durable, lasting as many as 15 years in 90% to 95% of the cases.

Acetabulum↗
PubMed1997

The in vitro and in vivo indomethacin release from self-setting bioactive glass bone cement.

The in vivo and in vitro drug release profiles from a self-setting bioactive CaO-SiO2-P2O5 glass bone cement containing indomethacin as a model drug were investigated. The cement containing 2% and 5% indomethacin (IMC) powder hardened within 5 min after mixing with ammonium phosphate buffer. After setting, in vitro drug release from drug-loaded cement pellets in a simulated body fluid (SBF) at pH 7.25 and 37 degrees C continued for two weeks. The hardened cement gradually formed low-crystallinity hydroxyapatite during the drug release test in SBF. An IMC-loaded cement device (2% and 5% drug) was implanted in the subcutaneous tissue on the back of rats. The in vivo IMC release from the cement increased and attained maximum levels (Cmax of 2% and 5% drug-loaded cements was 0.27 and 3.37 micrograms/ml, respectively) at Tmax, 3 and 0.5 d, respectively, upon subcutaneous (s.c.) administration in rats. This suggested that the s.c. administration of the cement provided IMC release for a much longer period than s.c. administration of the solution, and the plasma IMC concentration was dependent on the drug concentration in the cement. The plasma IMC concentration and the area under the curve from 2% and 5% IMC-loaded cements in rats were dependent on the concentration of IMC in the cements. The in vivo IMC concentration in plasma obtained by the deconvolution method was much lower than that delivered in SBF in vitro. Scanning electron microscopy and photomicrographs of cross sections showed that the bioactive bone cement had excellent biocompatibility with the surrounding soft tissues.

Animals↗
PubMed1991

An in vivo study on the merits of two glass ionomers for the cementation of orthodontic bands.

The purpose of this study was to investigate the cariostatic effect of two glass ionomer cements on in vivo demineralization of partly uncovered enamel beneath orthodontic bands. A 4-week clinical trial was conducted on a group of five patients with nine pairs of premolars to be extracted for orthodontic purposes. Specially designed orthodontic bands were cemented with either Ketac-Cem (K-C) or Aqua-Cem (A-C). A local cariogenic milieu was created between the buccal surface of the premolars and the inner surface of the bands to secure plaque accumulation. The mineral content of the teeth was quantified by microradiography. The data were compared with data from a previous study of patients in the same age group with bands that had been cemented with a non-F cement. After comparison with the non-F group, the lesion depth (ld) was reduced by 63% for K-C and by 55% for A-C. This reduction was statistically significant at the 2.5% level (t test). The total mineral loss in teeth cemented with glass ionomer cements (delta Z) was reduced, in comparison with the loss in teeth cemented with non-F cement, by 49% with K-C and by 27% with A-C. The differences were statistically significant only for the K-C group (t test, p less than 0.025). There were no significant differences between the two glass ionomer cements with respect to either lesion depth or total mineral loss values (paired t test; p greater than 0.05). This investigation shows that fluoride released from glass ionomer cements contributes substantially to demineralization "reduction." However, these cements do not provide complete caries protection in sites where access is difficult.

Acrylic Resins↗
PubMed1982

Influence of cementing medium on the accuracy of the remount procedure.

In light of the results of this study, a number of conclusions can be made with reference to full coverage castings. 1. Dental cement causes occlusal displacement. Zinc phosphate cement results in a greater displacement than does temporary zinc oxide-eugenol cement. 2. The disparity in seating of cast restorations obtained with no cement, temporary zinc oxide-eugenol cement, and zinc phosphate cement tends to reduce in magnitude with increasing taper of the tooth preparations. 3. Venting of crowns is an effective way of reducing the disparity in seating between no cement, temporary zinc oxide-eugenol cement, and zinc phosphate cement. 4. Remount records should be made with the restorations cemented with temporary zinc oxide-eugenol cement rather than held to the teeth by friction alone.

Acrylic Resins↗
PubMed1998

In vitro study of fracture incidence and compressive fracture load of all-ceramic crowns cemented with resin-modified glass ionomer and other luting agents.

STATEMENT OF PROBLEM: Anecdotal reports based on clinical observation have recently linked resin-modified glass ionomer luting agents with postcementation fracture of all-ceramic crowns. PURPOSE: This study evaluated the fracture incidence of In-Ceram and VitaDur Alpha porcelain jacket all-ceramic crowns cemented with 5 luting agents (Fuji I, Fuji Plus, Vitremer, Advance, and Panavia 21) during 2 months storage in 0.8% NaCl solution. MATERIAL AND METHODS: Fifty human maxillary premolar teeth were prepared for each ceramic system and divided into 5 subgroups of 10 teeth to be cemented with 5 luting cements. Specimens were observed for fracture lines and crack initiation at storage times up to 2 months. Incidence of fracture was analyzed with Fisher's Exact test. Specimens that did not fracture during storage were loaded in compression to failure. Failure loads were analyzed by analysis of variance and multiple pairwise comparisons. RESULTS: Only all-ceramic crowns cemented with Advance cement fractured during the 2-month observation period, and porcelain jacket crowns were found to fracture earlier and more frequently than In-Ceram crowns. Cracks initiated at the crown margin, and multiple crack lines were found as the time of storage increased. In-Ceram crowns were significantly stronger (140 +/- 21.5 kg) than porcelain jacket crowns (98.6 +/- 17.8 kg) at P <.05. For In-Ceram crowns, cement type did not influence failure load while for porcelain jacket crowns, Fuji I (110.5 kg) was significantly higher than Vitremer (86.6 kg) at P <.05. CONCLUSIONS: For the cements studied, only crowns cemented with Advance cement demonstrated fracture during 2-month storage. Results for the true resin-modified glass ionomer cements do not support anecdotal reports of fracture of all-ceramic crowns cemented with these materials.

Cementation↗
PubMed1999

Fluoride release of glass ionomer-based luting cements in vitro.

STATEMENT OF PROBLEM: There is considerable variation in generic formulation and in reported fluoride release from resin-modified glass ionomer luting cements. PURPOSE: This study compared fluoride release from 2 generically similar resin-modified glass ionomer luting cements (Vitremer and Advance) with release from 2 conventional glass ionomer luting cements (Ketac-Cem and Fuji I). MATERIAL AND METHODS: Ten specimen disks of each of the 4 luting cements were fabricated and immersed in deionized water in individual polystyrene jars. The jars were stored in a humidor at 37 degrees C between test periods. At the same time each day, for 28 days, fluoride release from each specimen disk was measured in parts per million by testing the storage water. RESULTS: The 4 luting cements tested showed an initial high concentration of fluoride release during the first week, followed by a gradual decrease over the study period. Vitremer luting cement demonstrated the greatest mean cumulative fluoride release in parts per million over the study period (198), followed by Fuji I (140), Ketac-Cem (110), and Advance (99) luting cements. CONCLUSIONS: Resin-modified glass ionomer luting cements showed fluoride release comparable to the conventional glass ionomer luting cements. Vitremer luting cement released more fluoride over the 28-day period than the other cements.

Analysis of Variance↗
PubMed2001

Kinetics of fluoride release from zinc oxide-based cements.

Considerable attention has been given to the release of the cariostatic fluoride ion from glass-based dental cements (dental silicate and glass ionomer). In these, the total available fluoride content is not precisely known since fluorine is distributed between the cross-linked aqueous salt matrix, partially dissolved glass, and undissolved glass. In analogous cements based on zinc oxide the fluoride is added as highly soluble SnF2. The object of this study is to compare the F- ion release profiles of commercial zinc polycarboxylate and zinc phosphate containing 4.4 and 3.6% SnF2, respectively. Mixed cements were clamped in split ring moulds to produce discs of 10 mm x 1 mm after storage at 37 degrees C for 1 h. Each was weighed and immersed in 10 ml of deionised water. When this changed, at 13 time intervals up to 98 days, the fluoride content was measured using an ion selective electrode. The mean (N = 3) values obtained were expressed cumulatively [F] in micromol F ion/g cement. The total [F] released was 111 for the zinc polycarboxylate and 286 for zinc phosphate compared with total F in the cements of 561 and 464, respectively. When the cumulative [F] was plotted versus t(1/2) close associations were found for both cements. For the polycarboxylate the regression line [F] = 10.6t(1/2) + 9.9 fitted well over the whole 98 days (R = 0.997). For the phosphate a better fit regression line was obtained using results up to 32 days only; [F] = 36.8t(1/2) - 8.4 (R = 0.999). For t > 32 days results increasingly deviated from this line. These results fitted a regression line of the form [F] = 81.7log(e) t - 87.3 (R = 0.9997). Comparisons are made with data from previous authors both for zinc phosphate cement and glass-based cements and with diffusion theory of F ion release. It is concluded that zinc-based cements provide some indications of how glass-based cements may behave over long periods of release and that zinc phosphate is the material of clinical choice for orthodontic cementation if maximal fluoride release is the prime criterion.

Cariostatic Agents↗
PubMed2001

Post retention: the effect of sequence of post-space preparation, cementation time, and different sealers.

Many endodontic sealers contain constituents that have been shown to inhibit the polymerization of resin cements. This may be important when prefabricated posts are cemented at the same appointment as root canal obturation. This study evaluated the effects of cementing posts with a resin cement immediately or at a delayed time period after obturation using Roth's 801 Elite Grade or AH26 sealer cements. The contribution of mechanical post-space preparation was also assessed as a critical variable. One hundred twenty extracted canines were randomly divided into eight experimental groups. The variables evaluated were the order of post preparation (either before or after obturation), the type of sealer used, and the time of post cementation. All teeth received a stainless steel #6 Parapost XP cemented with a resin cement, Panavia 21. Each experimental group underwent tensile testing for retention using an Instron universal testing machine. For both sealers posts cemented in teeth in which the canal was obturated before post-space preparation and thus had sealer-contaminated dentin removed by the space preparation procedure had significantly higher retentive values than those obturated after post-space preparation in which contaminated dentin might remain. Sealer used and time of cementation had no specific effect on retention. Achieving a clean, "freshened" dentinal surface during mechanical post-space preparation seems to be a critical variable for post retention when a resin cement is used.

Analysis of Variance↗
PubMed1992

Early bond strength of luting cements to a precious alloy.

Previous studies have reported that glass-ionomer and adhesive resin cements can bond to various alloys, while zinc phosphate cements lack this adhesive property. This study evaluated the bonding properties of three luting cements during the first seven days after cementation. Thirty cylinders were cast with a high-noble porcelain-fused-to-metal (PFM) alloy and luted in pairs with one of the cements. The joints were stored in water at 37 degrees C for one, two, or seven days before being fractured in shear. The cylinders were re-used to provide 40 joints within each test group. The data were subjected to a Weibull analysis, a curve-fitting method shown to be appropriate for comparing the bond strengths of dental materials. The results showed that the zinc phosphate cement was the weakest material, whereas the adhesive resin produced the strongest joints. Microscopic observations of the fractured samples did not reveal any specific differences between the samples in terms of their mechanism of fracture. The glass-ionomer cement reached its maximum bond strength after two days, whereas storage time had no influence on the zinc phosphate cement. The adhesive resin cement was slightly, but not significantly, weaker after one week in water. We suggest that excessive loading of restorations cemented with glass ionomer should be avoided for the first two days after the placement. The use of an adhesive resin cement can be recommended on endodontically treated teeth, but further studies are needed to evaluate its biocompatibility and adhesion to dentin.

Acrylic Resins↗
PubMed1978

Effect of cleansing procedures on the retentive ability of two luting cements to ground dentin in vitro.

A method has been described to measure the retention of luting cements to ground dentin in vitro. Using a specially designed apparatus, a circular disc of cement was produced on a ground dentin surface of equal diameter. In a universal testing machine a tensile stress was applied to the cement disc pulling it parallel with the dentin surface at right angles to the diamond grooves until separation. The effect of two different cleansing procedures on the retentive ability of two dental cements was investigated. The cleansing procedures were: rubbing ground dentin with Tubulicid or polishing with wet pumice. The cements studied were a polycarboxylate cement (Durelon) and a zinc phosphate cement (De Trey's Zink Zement Improved). The retentive ability of the polycarboxylate cement showed values from six to seventeen times those of the zinc phosphate cement. The retentive ability of zinc phosphate cement was only slightly affected by the two cleansing procedures, while for polycarboxylate cement it was somewhat reduced following rubbing with Tubulicid and greatly improved after polishing with pumice and water.

Adhesiveness↗
PubMedDate not supplied

Load fatigue of compromised teeth: a comparison of 3 luting cements.

PURPOSE: This study compared the number of cycles to failure of central incisors restored with full cast crowns and then cemented with 3 different luting cements. MATERIALS AND METHODS: Fifteen human maxillary central incisors received cast post-and-core restorations. These were cemented with zinc phosphate. The teeth were then divided into 3 groups of 5 samples each. Each tooth had a ferrule length of 1.0 mm and was prepared for a full crown. A waxing jig was used to standardize the load application point on all waxed crowns. Complete cast crowns were cemented to the compromised teeth using 3 different luting cements: a zinc phosphate cement (control group), a resin-modified glass-ionomer cement, and a resin cement with a dentin bonding agent. A fatigue load of 1.5 kg was applied at a rate of 72 cycles per minute until failure of the cement layer occurred between the crown and the tooth (preliminary failure). The independent variable was the number of load cycles required to create preliminary failure. An electrical resistance strain gauge was used to provide evidence of preliminary failure. RESULTS AND CONCLUSION: The resin cement samples had a significantly higher number of load cycles to preliminary failure than both the zinc phosphate and the resin-modified glass ionomer (P < or = 0.05). There was no significant difference between the zinc phosphate and the resin-modified glass-ionomer cements.

Analysis of Variance↗
PubMedDate not supplied

Influence of fatigue loading on the performance of adhesive and nonadhesive luting cements for cast post-and-core buildups in maxillary premolars.

PURPOSE: This study evaluated the influence of fatigue loading on the performance of an adhesive and a nonadhesive cement for cast post-and-core restorations in maxillary premolars. MATERIALS AND METHODS: The adhesive cement used was Panavia 21, a resin-based composite cement, and the nonadhesive cement was PhosphaCem/C, a zinc-oxy-phosphate cement. The coronal sections of single-rooted human maxillary premolars were removed at the level of the proximal CEJ. After endodontic treatment, a cast post and core was prepared for each tooth and cemented into the root canal with either Panavia 21 (n = 8) or PhosphaCem/C (n = 8). Half of the specimens from each cement group were exposed to fatigue loading almost perpendicular to the axial axis; the other half were used as controls. Three parallel transverse root sections were cut from each specimen and used for evaluation of the influence of fatigue loading. For each section, cement integrity was studied by SEM, and retention strength of the cemented post section was determined with a push-out test. RESULTS: For SEM evaluation and the push-out test, Panavia 21 proved significantly better than PhosphaCem/C. However, fatigue loading did not show any effect. CONCLUSION: Under the conditions of this study, fatiguing of cemented cast post-and-core restorations was not decisive as a single test to evaluate the quality of the cement.

Adhesives↗
PubMed1997

Cement removal from restorations luted to titanium abutments with simulated subgingival margins.

STATEMENT OF PROBLEM: The process of removing excess cement from subgingival margins after cementation of restorations to implant abutments may lead to scratching of the abutments or incomplete cement removal. PURPOSE: The purpose of this study was to investigate and to compare the surfaces of abutments after the removal of three cements (glass ionomer, resin, and zinc phosphate) by use of three instruments (gold coated scaler, rigid plastic scaler, and stainless steel explorer). MATERIAL AND METHODS: Six investigators removed zinc phosphate, glass ionomer, and resin cements with explorers, gold coated scalers, and rigid plastic scalers with a model simulating clinical conditions. The surface of Brånemark abutments with cemented restorations were examined with a microscope at 20x for scratches and cement remnants. RESULTS: Statistical analysis of the results were inconclusive about which combination of instrument and cement worked most effectively. CONCLUSION: A surprising amount of cement remnants and scratching of abutments was observed. Although the six investigators were experienced in prosthodontic and implant procedures, there was variation in the results of their cement removal.

Cementation↗
PubMed2000

Effect of cement type on retention of a tapered post with a self-cutting double thread.

OBJECTIVES: The aim of this in vitro study was to examine the effect of varying the cement type on the retention of a prefabricated tapered titanium post with a self-cutting double thread (Perma-tex activ). METHODS: A total of 130 suitable roots from extracted human permanent teeth were selected. Post holes were prepared using the instruments supplied with the post system. One-hundred-twenty posts (medium size) were luted with one of four luting agents: a zinc-phosphate cement (Harvard), a glass-ionomer cement (Ketac Cem), a compomer luting agent (Dyract Cem), and a new capsulated composite luting system (Compolute). The cement groups were subdivided into three treatment groups with 10 posts each: group 1 (4-week water storage at 37 degrees C), group 2 (4-week water storage at 37 degrees C, 4000 cycles 5-55 degrees C), group 3 (4-week water storage at 37 degrees C, 4000 cycles 5-55 degrees C, 3 x 4 min mechanical stress: 40N vibrations). Another 10 posts inserted without cement and stored like group 1 served as a control. Retention was measured on a universal testing machine (Zwick Z050/TH3A) with a crosshead speed of 0.1cm/min. Data were analyzed using ANOVA with a Bonferroni or Tamhane adjustment for multiple comparisons (significance level alpha=0.05). RESULTS: In group 1, Dyract Cem was significantly more retentive than the other three cements and the control group (no cement). In group 2, Compolute demonstrated significantly higher retention than Harvard and Ketac Cem. In group 3, Compolute, Dyract Cem, and Ketac Cem obtained higher retentive values than Harvard without differing from one another. Within the cement groups, thermocycling (group 2) caused a significant decrease in retention compared to group 1 only for Dyract Cem. All cements except Compolute were different from group 1 after a combination of thermocycling and mechanical stress (group 3). CONCLUSIONS: The retention of the tapered post with a self-cutting double thread was significantly influenced by the cement type used.

Analysis of Variance↗
PubMed2001

The influence of ultrasound on the retention of cast posts cemented with different agents.

AIM: The aim of this study was to evaluate the influence of ultrasound during the removal of posts cemented with either zinc phosphate cement, glass ionomer cement or resin cement. METHODOLOGY: Eighty-four single-rooted teeth were prepared and after cementation of cast posts, they were randomly divided into six groups of 14. Group 1, 2 and 3 did not receive ultrasonic vibration, whilst groups 4, 5 and 6 received ultrasonic vibration for 10 min. The force necessary for post removal was determined using a universal testing machine. Results were statistically analysed using ANOVA and Tukey tests (5%). RESULTS: The application of ultrasonic vibration reduced the retention provided by zinc phosphate and glass ionomer cements by 39% and 33%, respectively. CONCLUSIONS: A statistically significant reduction in the force necessary to remove posts cemented with zinc phosphate and glass ionomer cements occurred following application of ultrasound. The application of ultrasonic vibration did not influence the retention of cast posts cemented with resin cement.

Analysis of Variance↗