Bond strength of luting cements to dentin is a critical consideration for success of complete cast crowns. This study was performed to evaluate the relationship between surface characteristics of teeth prepared for complete cast crowns and retention of cemented restorations. Eighty artificial crowns were cast for standardized complete crown tooth preparations accomplished with the use of a special device on recently extracted human teeth. Coarse diamond(#102R, Shofu) and superfine finishing diamond(#SF102R, Shofu) burs of similar shape were used. Crowns in each group were randomly subdivided into four subgroups of 10 for luting cements selected for this study: zinc phosphate cement (FLECK'S), polycarboxylate cement (Poly-F), reinforced glass ionomer cement (Fuji PLUS), and adhesive resin cement (Panavia 21). Retention was evaluated by measuring the tensile load required to dislodge the artificial crown from tooth preparations with an Instron testing machine, and analysed by one-way ANOVA and Student's t-test. The obtained results were as follows ; 1. When tooth preparation was done with coarse diamond bur, retentive force was diminished in order of Panavia 21, Fuji PLUS, FLECK'S, and Poly-F. Retentive forces showed the significant difference between Fuji PLUS group and FLECK'S group(p<0.001). 2. When tooth preparation was done with superfine diamond bur, retentive force was diminished in order of Fuji PLUS, Panavia 21, FLECK'S and Poly-F. Retentive forces showed the significant difference between Panavia 21 group and FLECK'S group(p<0.001). 3. Retentive force in coarse tooth surfaces was significantly higher than that in superfine tooth surface with all luting cements(p<0.001), and cement residues were almost retained with in the cast crown in all groups.
Adhesives ; Crowns* ; Dental Instruments ; Dentin ; Glass Ionomer Cements ; Humans ; Polycarboxylate Cement ; Resin Cements ; Tooth Preparation ; Tooth* ; Zinc Phosphate Cement

PURPOSE: The objective of this study was to evaluate the influence of various cement types on the stress distribution in monolithic zirconia crowns under maximum bite force using the finite element analysis. MATERIALS AND METHODS: The models of the prepared #46 crown (deep chamfer margin) were scanned and solid models composed of the monolithic zirconia crown, cement layer, and prepared tooth were produced using the computer-aided design technology and were subsequently translated into 3-dimensional finite element models. Four models were prepared according to different cement types (zinc phosphate, polycarboxylate, glass ionomer, and resin). A load of 700 N was applied vertically on the crowns (8 loading points). Maximum principal stress was determined. RESULTS: Zinc phosphate cement had a greater stress concentration in the cement layer, while polycarboxylate cement had a greater stress concentration on the distal surface of the monolithic zirconia crown and abutment tooth. Resin cement and glass ionomer cement showed similar patterns, but resin cement showed a lower stress distribution on the lingual and mesial surface of the cement layer. CONCLUSION: The test results indicate that the use of different luting agents that have various elastic moduli has an impact on the stress distribution of the monolithic zirconia crowns, cement layers, and abutment tooth. Resin cement is recommended for the luting agent of the monolithic zirconia crowns.
Bite Force ; Computer-Aided Design ; Crowns* ; Dental Cements ; Dental Stress Analysis ; Finite Element Analysis* ; Glass ; Glass Ionomer Cements ; Polycarboxylate Cement ; Resin Cements ; Tooth ; Zinc Phosphate Cement ; Zirconium

OBJECTIVETo evaluate the effect of Zinc oxide-eugenol cement and Gluma desensitizer on the sheer bond strength of three kinds of dentin bonding agents. The three dentin bonding agents were Zinc phosphate cement, Glass ionomer cement and Super-Bond C&B. To find the theory depending for the using of different protective methods and the selecting of different kinds of dentin bonding agents in prepared abutment teeth.

METHODSThe buccal surfaces of ninety freshly extracted human premolars were flattened to expose an adequate area of lower dentin. Followed by wet-grinding on a series of silicon carbide paper from number 320, 400, 600 grit to produce the dentin bonding surface. The teeth roots were embedded in self-curing resin with the crown out of the resin. The embedded ninety teeth were divided randomly into three groups. The group A was control and the dentin surfaces were not treated. The group B was covered with a paste of Zinc oxide-eugenol cement. The group C was covered with Gluma desensitizer. Calculating the sheer strength between three bonding agents and dentin after the two treatments of dentin surface. The results were statistically assessed with SPSS software. Dentin surfaces were observed with scanning electron microscope (SEM).

RESULTSThe sheer bond strengths of Zinc phosphate cement had significant decrease (P<0.05), especially the C1 group. The sheer bond strengths of Glass ionomer cement and Super-Bond C&B had no significant difference.

CONCLUSIONZinc oxide-eugenol cement and Gluma desensitizer could reduce the sheer bond strength of Zinc phosphate cement with dentin surface. Zinc oxide-eugenol cement and the Gluma desensitizer could not effect Glass ionomer cement and the Super-Bond C&B with dentin.

Boron Compounds ; Crowns ; Dental Bonding ; Dentin ; Dentin-Bonding Agents ; Glutaral ; Humans ; Methacrylates ; Methylmethacrylates ; Resin Cements ; Zinc Oxide-Eugenol Cement

Ultrasonic instruments transfer electrical energy to mechanical energy resulting in vibration used for various dental treatments. If we could know the effect of ultrasonic instruments on the dental cements within the cast crown, we could take care when conducting periodontal surgery and when using the ultrasonic instruments to remove cast crown, it would be much more convenient. The purpose of this study was to compare the bond strength of several dental cements according to ultrasonic instrumentation time In this study 4 types of cements were used to cement the specimens. They were treated with ultrasonic instrumentation for 0-5 minutes and the change in bond strength were statistically compared The results were as follows : 1. The tensile bond strength of zinc phosphate cement decreased according to the increase in time of ultrasonic instrument and showed significant differance between 0 minutes and the others and between 1 minute and 2,3,4,5 minutes (P<0.05) 2. The tensile bond strength of polycarboxylate cement decreased according to the increase in time of ultrasonic instrument and showed significant differance between 5 minutes and the others and between 4 minute and 0 minutes (P<0.05) 3. The tensile bond strength of zinc phosphate cement decreased according to the increase in time of ultrasonic instrument and showed significant differance between 5 minutes and the others (P<0.05) 4. The tensile bond strength of resin cement showed no statistically differences according to the ultrasonic instrumentation time In conclusion, it this considered that zinc phosphate cement is most affected by ultrasonic instrumentations and resin cement is the least affected. When using ultrasonic instruments the result above should be used as an index.
Crowns ; Dental Cements* ; Polycarboxylate Cement ; Resin Cements ; Ultrasonics* ; Vibration ; Zinc Phosphate Cement

The purpose of this study was to confirm the formation of hybrid layer and resin tags in dentin tissue and the possibility of bonding between luting cements used for the prosthesis and the resinous surface coated with resin bonding agents to prevent the dentin hypersensitivity after abutment preparation. Some resin bonding agents, which may have the possibility of bonding with polyacrylic acid as a liquid ingredient of polycarboxylate and glass ionmer coments, were selected. All-Bond desenstizer containing NTG-GMA and BPDM, Scotch-Bond Multipurpose plus containing HEMA, and XR-bond cotaining organophosphate were selected as a coating agent. Dental cements were zinc phosphate, polycarboxylate, and glass ionomer cement. After the exposed dentin surface of premolars was ethced with 10% phosphoric acic and coated with resin bonding agents, the monophology of treated surfaces and the resin tags and hybrid layers on sectioned surfaces were observed by SEM. Shear bond strength between the resin bonding agents and 3 kinds of cements was measured 24 hours after bonding. On the debonded surfaces of the shear bond strength tested specimens, the cement tags and the bonding sites between the resin materials and cements were examined by SEM. Following conclusions were drawn : 1. Coating of dentin with resin bonding agents had no effect on the shear bond strength of zinc phosphate cement. 2. Both of polycarboxylate and glass ionomer cements showed the increased shear bond strength by the dentinal coating with Scotch-Bond Multipurpose plus containing HEMA. However, in the case of dentinal coating with some agents containing NTG-GMA and BPDM or organophosphate, polycarboxylate cement exhibited the lowered shear bond strength, and glass ionomer cement showed the unchanged shear bond strength. 3. Complete obstructions of dentinal tubules were observed on the dentin coasted with All-Bond desensitizer or XR-bond, but distinct shape of the orifices of dentinal tubules was observed consistently on the dentin coated with Scotch-Bond Multipurpose plus 4. The hybrid layer was thickest on the dentin coated with All-Bond desensitizer, and the length of resin tags was longest one the dentin coated with Scotch-Bond Multipurpose plus. 5. On the debonded specimens which had been bonded with polycarboxylate cement or glass ionomer cement after coating with Scotch-Bond Multipurpose plus, the cement tags and the bonding sites between the resinous surface and the cements could be examined.
Acyclovir ; Bicuspid ; Dental Cements ; Dentin Sensitivity ; Dentin* ; Glass ; Glass Ionomer Cements ; Polycarboxylate Cement ; Prostheses and Implants ; Zinc ; Zinc Phosphate Cement

OBJECTIVEThis study was to compare the retention of posts fabricated by different methods and cemented with various cements in order to provide a guidance for clinical choice of post fabrication methods and luting cements.

METHODSNinety human maxillary anterior teeth were sectioned by the cementoenamel junction and post-holes were prepared. All roots were embedded in the center of plastic cylinders and paralleled with the cylinder. All samples were divided into 9 groups randomly and equally. Posts fabricated with different methods were then cemented with different luting cements. Each sample was placed into a specialized jig and mounted on a tensile testing machine with crosshead speed of 5 mm/min. Constant tensile force was applied until the post was dislodged, and the tensile force required to dislodge the cemented post was recorded.

RESULTSThe mean retention force of parapost and direct post demonstrated significantly higher than that of indirect post did (P < 0.05), but there was no significant difference between parapost and direct post(P > 0.05). The mean retention of parapost cement demonstrated significantly higher than that of ZPC and HY-Bond cement did (P < 0.05), but there was no significant difference between ZPC and HY-Bond cement (P > 0.05).

CONCLUSIONDifferent fabrication methods and luting cements significantly affect the retention of posts; and there exists an interaction between different fabricating methods and luting cements.

Cementation ; methods ; Dental Bonding ; Dental Cements ; chemistry ; Dental Prosthesis Design ; Dental Prosthesis Retention ; Dental Stress Analysis ; Dentin-Bonding Agents ; chemistry ; Glass Ionomer Cements ; chemistry ; Humans ; Materials Testing ; Post and Core Technique ; instrumentation ; Resin Cements ; chemistry ; Tensile Strength ; Zinc Phosphate Cement ; chemistry

OBJECTIVETo study the effects of two different endodontic sealers on the bond strength of two fiber posts cemented with adhesive resin cement.

METHODSTwenty-eight crownless human maxillary central incisors were prepared with the step-back technique and randomly divided into four groups according endodontic sealer and fiber: Group A, Cortisomol sealer+Matchpost fiber post; Group B, Cortisomol sealer+Macrolock fiber post; Group C, Guttaflow sealer+Matchpost fiber post; Group D, Guttaflow sealer+Macrolock fiber post. One week after fiber posts were bonded, a thin-slice push-out test was performed in a universal machine. Morphologic structure of the root canal dentin surfaces etched and the adhesive interfaces were examined by scanning electron microscopy (SEM).

RESULTSThe bond strengths of 4 groups were (7.06 +/- 3.22), (9.31 +/- 3.61), (6.90 +/- 3.13), (9.71 +/- 3.42) MPa. The bond strengths of group B and D were significantly higher than that of group A and C (P < 0.05). There was no significant difference between group A and C, group B and D (P > 0.05). The cervical third had the highest mean push-out bond strength, next to middle third and apical third (P < 0.01). SEM showed that larger numbers of the dentin tubules were open after the root canals were etched and penetration of resin tags into the dentinal tubules increased in the coronal root region when compared with the apical root region.

CONCLUSIONThe shear bond strength doesn't have relationship with endodontic sealers. The serration significantly increases the retention of fiber post. The bond strengths are different at the three root segment sites.

Dental Bonding ; Dentin ; Dentin-Bonding Agents ; Dimethylpolysiloxanes ; Drug Combinations ; Gutta-Percha ; Humans ; Incisor ; Post and Core Technique ; Resin Cements ; Root Canal Therapy ; Tooth Root ; Zinc Oxide-Eugenol Cement

OBJECTIVETo examine the compositions of those adhesion modes between luting cements and canal dentin, and to evaluate the dentin-cement-post interface by Laser-Ranian spectroscopy.

METHODSThree representative luting cements (zinc phosphate, glass ionomer and resin cements), two kinds of prefabricated posts (titanium and fiber-glass), six extracted intact human maxillary anterior teeth were used canal dentin after endodontic treatment. Laser-Raman spectroscopy measure of cement, post and canal dentin before and after luting together.

RESULTSThere are no evident Raman spectra change cross the ZPC/dentin interface and glass ionomer/dentin interface, while cross the resin/dentin interface and resin/glass fiber post interface can be seen special Raman spectra.

CONCLUSIONLaser-Raman microspectroscopy is a useful analytical technique for evaluation interface between dentin and luting cements. Resin cement may interact with dentin and glass fiber post.

Cementation ; Dental Bonding ; Dental Cements ; Dental Cementum ; Dental Pulp Cavity ; Dentin ; Dentin-Bonding Agents ; Glass Ionomer Cements ; Humans ; Post and Core Technique ; Resin Cements ; Root Canal Therapy

PURPOSE: This study was performed to investigate the retrievability of the cemented crown from the cementation type implant abutment. MATERIAL AND METHOD: The cementation type implant abutments (NEOBIOTECH implant abutment regular, 3 degree taper, 10mm length, 4mm diameter, Ti grade III, machined surface, Hwasung, Kyunggi-do) and cemented crowns were divided into 3 groups, depending on their hole angles formed in the crowns for their retrievability. The abutments and crowns were luted with 4 kinds of cements and separation test using metal wedge was executed with Instron 4465 Universal Testing Machine and the maximum impact force of the modified crown ejector was measured. RESULTS AND CONCLUSION: 1. All of the cementation type implant abutments and cemented crowns were separated with relatively small force by metal wedge. 2. The retrieving force was minimum when the metal wedge was applied perpendicular to the axis of abutment. 3. The force for retrieving crowns from abutments was maximum in resin cement group, and reduced in orders of zinc phosphate cement, glass ionomer cement and zinc oxide eugenol cement. 4. The maximum force obtained by the crown ejector was higher than the retrieval force in ZOE and GI cement and lower than that in ZPC and resin cement. 5. If it has similar conditions clinically, the cemented crowns luted with 2 types of cements (ZOE, GI cement) can be safely retrieved from the cementation type implant abutments by the modified crown ejector.
Axis, Cervical Vertebra ; Cementation* ; Crowns ; Glass Ionomer Cements ; Resin Cements ; Zinc Oxide-Eugenol Cement ; Zinc Phosphate Cement

OBJECTIVETo investigate the effect of four different cements on the bonding effectiveness of root canal dentine and fiber post before and after different treatments.

METHODSA total of 216 freshly extracted sound single-root-canal mandibular premolars were randomly divided into four groups. After root canal treatment and post space preparation being conducted on the premolars, Fuji I, Fuji Cem, RelyX Unicem, RelyX ARC were used respectively to bond fiber posts and were marked with group A, B, C, and D. Microleakage, micromorphology of the bonded interfaces, and pull-out bond strength were evaluated in the immediate group, thermocycling group and thermomechanical loading group.

RESULTSIn the immediate group, samples in group D showed the highest bond strength [(278 ± 26)N], followed by group C[ (219 ± 12) N], B[ (104 ± 23) N] and A[(73 ± 8) N]. Significant differences were found among all groups (P < 0.05) . A significant increase in bond strength was found in group A and B, whereas a decrease tendency was detected in group C and D after different treatments.Scanning electron microscope indicated that some little gaps were observed in group D after treatment, while a more intense bonding interface was found in group A and B. Microleakage scores in group A and B were lower than those in group C and D after aging treatments.

CONCLUSIONSResin cement can achieve a better immediate bond strength, while resin-modified resin cement may acquire a better long-term retention.

Bisphenol A-Glycidyl Methacrylate ; Dental Bonding ; Dental Cementum ; Dental Stress Analysis ; Dentin ; Dentin-Bonding Agents ; Glass ; Glass Ionomer Cements ; Humans ; Materials Testing ; Polyethylene Glycols ; Polymethacrylic Acids ; Post and Core Technique ; Resin Cements