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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Restorative Dentistry and Endodontics
Journal Basic Information
Journal DOI :
The Korean Academy of Conservative Dentistry
Editor in Chief :
Volume & Issues
Volume 37, Issue 3 - Aug 2012
Volume 37, Issue 2 - Jun 2012
Volume 37, Issue 1 - Mar 2012
Selecting the target year
An evaluation of the accuracy of Root ZX according to the conditions of major apical foramen
Park, Shin-Young ; Lee, Dong-Kyun ; Hwang, Ho-Keel ;
Restorative Dentistry and Endodontics, volume 37, issue 2, 2012, Pages 68~73
DOI : 10.5395/rde.2012.37.2.68
Objectives: The purpose of this study was to assess the accuracy of Root ZX (J. Morita Corp.) according to the location of major foramen and open apex. Materials and Methods: 81 mandibular premolars with mature apices were selected. After access preparation, 27 teeth were instrumented to simulate open apices. 54 teeth were classified according to location of major foramen under surgical microscope (
). The file was fixed at the location of apical constriction by Root ZX using glass ionomer cement .The apical 4 mm of the apex was exposed and photo was taken and the distance from file tip to the major foramen was measured by calibrating metal ruler on graph paper. The results were statistically analyzed using ANOVA and Scheffe test at p < 0.05 level. Results: Mean distance from file tip to major foramen was 0.308 mm in Tip foramen group (I), 0.519 mm in Lateral foramen group (II) and 0.932 mm in open apex group (III). Root ZX located apical constriction accurately within
in group I of 85.71%, in group II of 59.09%, and in group III of 33.33%. There was a statistically significant difference between group I and III (p < 0.05). Conclusion: Root ZX located apical constriction accurately regardless of location of major foramen. However, Root ZX couldn't find it in open apex. Clinicians have to use a combination of methods to determine an appropriate working length at open apex. It may be more successful than relying on just electronic apex locator.
Effect of internal stress on cyclic fatigue failure in K3
Kim, Jun-Young ; Kim, Jin-Woo ; Cho, Kyung-Mo ; Park, Se-Hee ;
Restorative Dentistry and Endodontics, volume 37, issue 2, 2012, Pages 74~78
DOI : 10.5395/rde.2012.37.2.74
Objectives: This study aimed to evaluate the relationship between the cyclic fatigue of a K3 file and internal stress intentionally induced until the activation of the autostop function of the torque-controlled motor. Materials and Methods: K3 (Sybron Endo) .04 and .06 taper, size 25, 30, 35, 40 and 45 were used in this study. To give the internal stress, the K3 files were put into the .02 taper Endo-Training-Bloc (Dentsply Maillefer) until the activation of the auto-stop function of the torque-controlled motor. The rotation speed was 300 rpm and torque value was 1.0
. K3 were grouped by the number of induced internal stress and randomly distributed to 4 experimental groups (n = 10, Stress 0 [control], Stress 1, Stress 2 and Stress 3). For measuring the cyclic fatigue failure, the K3 files were worked against a sloped glass block and time for file separation was recorded. Data was statistically analyzed Statistical analyses were performed using two-way ANOVA and Duncan post-hoc test at p < 0.05 level. Results: Except .04 taper size 30 in Stress 1 group, there were statistically significant differences in time for file separation between control and all experimental groups. K3 with .04 taper showed higher cyclic fatigue resistance than those of .06 taper. Conclusion: In the limitation of this study, the cyclic fatigue of the K3 file was influenced by the accumulated internal stress from use until the auto-stop function was activated by the torque-controlled motor. Therefore, clinicians should avoid the reuse of the K3 file that has undergone auto-stops.
Effect of internal stress on cyclic fatigue failure in .06 taper ProFile
Jung, Hye-Rim ; Kim, Jin-Woo ; Cho, Kyung-Mo ; Park, Se-Hee ;
Restorative Dentistry and Endodontics, volume 37, issue 2, 2012, Pages 79~83
DOI : 10.5395/rde.2012.37.2.79
Objectives: The purpose of this study was to evaluate the relation between intentionally induced internal stress and cyclic fatigue failure of .06 taper ProFile. Materials and Methods: Length 25 mm, .06 taper ProFile (Dentsply Maillefer), and size 20, 25, 30, 35 and 40 were used in this study. To give the internal stress, the rotary NiTi files were put into the .02 taper, Endo-Training-Bloc (Dentsply Maillefer) until auto-stop by torque controlled motor. Rotary NiTi files were grouped by the number of induced internal stress and randomly distributed among one control group and three experimental groups (n = 10, Stress 0 [control], Stress 1, Stress 2 and Stress 3). For cyclic fatigue measurement, time for separation of the rotary NiTi files was recorded. The fractured surfaces were observed by field emission scanning electron microscope (FE-SEM, SU-70, Hitachi). The time for separation was statistically analyzed using two-way ANOVA and post-hoc Scheffe test at 95% level. Results: In .06 taper ProFile size 20, 25, 30, 35 and 40, there were statistically significant difference on time for separation between control group and the other groups (p < 0.05). Conclusion: In the limitation of this study, cyclic fatigue failure of .06 taper ProFile is influenced by internal stress accumulated in the files.
Colorimetric comparison of single layered dental composite with double layered dental composite
Song, Young-Sang ; Kim, Ja-Hyun ; Lee, Bin-Na ; Jang, Ji-Hyun ; Chang, Hoon-Sang ; Hwang, Yun-Chan ; Oh, Won-Mann ; Hwang, In-Nam ;
Restorative Dentistry and Endodontics, volume 37, issue 2, 2012, Pages 84~89
DOI : 10.5395/rde.2012.37.2.84
Objectives: This study analyzed the difference in color caused by different thickness in enamel layer of composite resins when applied with single and layering placement technique, and evaluated if the results agreed with the shade guide from the manufacturers to verify reliability of the color matching process of the manufacturers. Materials and Methods: For single composite resin samples, 6 mm diameter and 4 mm thickness cylindrical samples were fabricated using Ceram-X mono (DENTSPLY DeTrey) and CIE
values were measured with spectrophotometer. Same process was done for layering composite resin samples, making 3 dentinal shade samples, 4 mm thickness, for each shade using Ceram-X duo (DENTSPLY DeTrey) and enamel shade resins were layered in 2 mm thickness and CIE
values were measured. These samples were ground to 0.2 mm thickness each time, and CIE
values were measured to 1 mm thickness of enamel shade resin. Results: Color difference (
) between single and layering composite resin was 1.37 minimum and 10.53 maximum when layering thicknesses were between 1 mm and 2 mm and 6 out of 10 same shade groups suggested by manufacturer showed remarkable color difference at any thickness (
> 3.3). Conclusion: When using Ceram-X mono and duo for composite resin restoration, following the manufacturer's instructions for choosing the shade is not appropriate, and more accurate information for Ceram-X duo is needed on the variation and expression of the shades depending on the thickness of the enamel.
Color and hardness changes in artificial white spot lesions after resin infiltration
Kim, Ji-Hoon ; Son, Ho-Hyun ; Chang, Ju-Hea ;
Restorative Dentistry and Endodontics, volume 37, issue 2, 2012, Pages 89~94
DOI : 10.5395/rde.2012.37.2.89
Objectives: The purpose of this study was to determine the effect of resin infiltration technique on color and surface hardness of white spot lesion (WSL) with various degrees of demineralization. Materials and Methods: Ten human upper premolars were cut and divided into quarters with a
window on the enamel surface. Each specimens were separated into four groups (n = 10) and immersed in demineralization solution to create WSL: control, no treatment (baseline); 12 h, 12 hr demineralization; 24 h, 24 hr demineralization; 48 h, 48 hr demineralization. Resin infiltration was performed to the specimens using Icon (DMG).
color parameters of the enamel-dentin complex were determined using a spectroradiometer at baseline, after caries formation and after resin infiltration. Surface hardness was measured by Vickers Micro Hardness Tester (Shimadzu, HMV-2). The differences in color and hardness among the groups were analyzed with ANOVA followed by Tukey test. Results: Resin infiltration induced color changes and increased the hardness of demineralized enamel. After resin infiltration, there was no difference in color change (
) or microhardness among the groups (p < 0.05). Conclusion: There was no difference in the effect of resin infiltration on color and hardness among groups with different extents of demineralization.
Effect of CQ-amine ratio on the degree of conversion in resin monomers with binary and ternary photoinitiation systems
Moon, Ho-Jin ; Shin, Dong-Hoon ;
Restorative Dentistry and Endodontics, volume 37, issue 2, 2012, Pages 95~102
DOI : 10.5395/rde.2012.37.2.95
Objectives: This study evaluated the effect of camphorquinone (CQ)-amine ratio on the C=C double bond conversion of resins with binary and ternary photoinitiation systems. Materials and Methods: Two monomer mixtures (37.5 Bis-GMA/37.5 Bis- EMA/25 TEGDMA) with binary systems (CQ/DMAEMA in weight ratio, group A [0.5/1.0] and B [1.0/0.5]) and four mixtures with ternary system (CQ/OPPI/DMAEMA, group C [0.1/1.0/0.1], D [0.1/1.0/ 0.2], E [0.2/1.0/0.1] and F [0.2/1.0/0.2]) were tested: 1 : 2 or 2 : 1 CQ-amine ratio in binary system, while 1 : 1 ratio was added in ternary system. The monomer mixture was cured for 5, 20, 40, and 300 sec with a Demetron 400 curing unit (Demetron). After each exposure time, degree of conversion (DC) was estimated using Fourier transform infrared (FTIR) spectrophotometer (Nicolet 520, Nicolet Instrument Corp.). The results were analyzed by ANOVA followed by Scheffe test, with p = 0.05 as the level of significance. Results: DC (%) was expressed in the order of curing time (5, 20, 40, and 300 sec). Group A (
); Group B (
); Group C (
); Group D (
); Group E (
); Group F (
). Conclusion: All the monomers with ternary photoinitiation system showed higher DC than the ones with binary system, until 40 sec. Concerning about the effect of CQ-amine ratio on the DC, group A converted into polymer more than group B in binary system. However, there was no significant difference among groups with ternary system, except group C when cured for 5 sec only.
An evaluation of canal curvature at the apical one third in type II mesial canals of mandibular molars
Yun, Hye-Rim ; Lee, Dong-Kyun ; Hwang, Ho-Keel ;
Restorative Dentistry and Endodontics, volume 37, issue 2, 2012, Pages 103~108
DOI : 10.5395/rde.2012.37.2.103
Objectives: The purpose of this study was to evaluate the buccolingual curvature at the apical one third in type II mesial canals of mandibular molars using the radius and angle of curvature. Materials and Methods: Total 100 mandibular molars were selected. Following an endodontic access in the teeth, their distal roots were removed. #15 H- or K-files (Dentsply Maillefer) were inserted into the mesiobuccal and mesiolingual canals of the teeth. Radiographs of the teeth were taken for the proximal view. Among them, type II canals were selected and divided into two subgroups, IIa and IIb. In type IIa, two separate canals merged into one canal before reaching the apex and in type IIb, two separate canals merged into one canal within the apical foramen. The radius and angle of curvature of specimens were examined. Results: In type II, mean radius of curvature in mesiolingual and mesiobuccal canals were 2.82 mm and 3.58 mm, respectively. The radius of the curvature of mesiolingual canals were significantly smaller than that of mesiobuccal canals in type II, and especially in type IIa. However, there were no statistically significant differences in radius of curvature between mesiobuccal and mesiolingual canals in type IIb and there were no significant differences in angle of curvature between type IIa and IIb. Conclusion: In this study, type II mesial canals of mandibular molars showed severe curvature in the proximal view. Especially, mesiolingual canals of type IIa had more abrupt curvature than mesiobuccal canals at the apical one third.
Re-establishment of occlusion after unilateral condylar fracture
Kim, Yoo-Kyung ; Park, Sung-Ho ; Roh, Byoung-Duck ;
Restorative Dentistry and Endodontics, volume 37, issue 2, 2012, Pages 109~112
DOI : 10.5395/rde.2012.37.2.109
Complications resulting from condylar fracture include occlusal disturbance due to loss of leverage from temporomandibular joint (TMJ). In general, closed reduction with active physical training has been performed, and under favorable circumstances, adaptation occurs in attempt to restore the articulation. The patient in this case report had unilateral condylar fracture accompanied with multiple teeth injuries, but he was left without any dental treatment for 1 mon which led to unrestorable occlusal collapse. Fortunately, delayed surgical repositioning of dislocated maxillary anterior teeth followed by consistent long-term physical training has been proved successful. Normal occlusion and satisfactory remodeling of condyle were obtained on 10 mon follow-up.
Pre-prosthetic minor tooth movement with elastic separating ring & provisional restoration modification: case report
Shin, Han-Eol ; Roh, Byoung-Duck ; Shin, Yoo-Seok ; Lee, Chan-Young ;
Restorative Dentistry and Endodontics, volume 37, issue 2, 2012, Pages 113~117
DOI : 10.5395/rde.2012.37.2.113
Proximal caries or coronal defect in posterior teeth may result in the loss of proximal space and drifting of neighboring teeth, which makes restoration difficult. Inability to restore proper contours and to align tooth axis properly are commonly encountered problems when planning tooth restoration. Moreover, tilted teeth aggravate periodontal tissue breakdown, such as pseudo-pocket, and angular osseous defect. The purpose of this case presentation is to describe a simple technique for inducing minor tooth movement with orthodontic separating ring and provisional restoration modification. This method was used to create crown placement space on mesially tilted molar. This method is easy, simple and efficient technique which could be used in interproximal space gaining in selected situation.
Prevention of tooth discoloration associated with triple antibiotics
Kim, Bo-Na ; Song, Min-Ju ; Shin, Su-Jung ; Park, Jeong-Won ;
Restorative Dentistry and Endodontics, volume 37, issue 2, 2012, Pages 118~121
DOI : 10.5395/rde.2012.37.2.118
Regenerative endodontics has a potential to heal a partially necrotic pulp, which can be beneficial for the continued root development and strengthening of immature teeth. For this purpose, triple antibiotic mixture of ciprofloxacin, metronidazole, and minocycline was recommended as intracanal medicament in an attempt to disinfect the root canal system for revascularization of a tooth with a necrotic pulp. However, discoloration of the tooth was reported after applying this. This case shows the idea for preventing the tooth discoloration using a delivery syringe to avoid the contact between the clinical crown and the antibiotics.
Vital tooth with periapical lesion: spontaneous healing after conservative treatment
Kim, Hyun-Joo ; Lee, Seung-Jong ; Jung, Il-Young ; Park, Sung-Ho ;
Restorative Dentistry and Endodontics, volume 37, issue 2, 2012, Pages 122~125
DOI : 10.5395/rde.2012.37.2.122
It is often presumed that apical periodontitis follows total pulp necrosis, and consequently root canal treatment is commonly performed. Periapical lesion development is usually caused by bacteria and its byproduct which irritate pulp, develop pulpitis, and result in necrosis through an irreversible process. Afterwards, apical periodontitis occurs. This phenomenon is observed as an apical radiolucency in radiographic view. However, this unusual case presents a spontaneous healing of periapical lesion, which has developed without pulp necrosis in a vital tooth, through conservative treatment.