• The Journal of Korean Academy of Prosthodontics
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• v.38 no.5
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• pp.618-630
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• 2000

As Fiber-reinforced composite restorations cannot be made without leaving a marginal gap, luting cements play a pivotal role in sealing the margins as a prevention against margnal leakage. A recently introduced adhesive resin cement system is claimed to adhere chemically, as well as mechanically, to tooth substances, dental alloys and porcelain. But when considering the clinical variation conventional cementation using Zinc Phosphate and Glass-Ionomer can be requested. A vitro study was undertaken to compare microleakage and marginal fitness of Fiber-reinforced composite crowns(Targis/Vectris) depending upon luting cements. Fifty non-carious human premolar teeth were randomly divided into five experimental groups of 10 teeth each and luted with five luting cements. ($Bistite\;II^(R),\;Super-bond^(R),\;Variolink\;II^(R)$), Zinc phosphate and Glass-Ionomer cement) After 24 hours of being luted, all specimens were thermocycled 300 times through water bath of $5^{\circ}C\;and\;55^{\circ}C$ in each bath, then the quality of the marginal fitness was measured by the Digital Microscope and marginal leakage was characterized using Dye Penetration technique and the Digital Microscope The results were as follows : 1. The mean values of marginal fit were Bistite II($46.78{\mu}m$), Variolink II($56.25{\mu}m$), Super-Bond($56.78{\mu}m$), Glass-Ionomer($99.21{\mu}m$), Zinc Phosphate($109.49{\mu}m$) indicated a statistically significant difference at p<0.001. 2. The mean microleakage values of tooth-cement interface, restoration-cement interface were increased in the order of Variolink II, Bistite II, Super-Bond, Glass-Ionomer, Zinc Phosphate 3. Crowns luted with resin cement (Bistite II, Super-Bond, Variolink II, etc) exhibited less marginal gap and marginal leakage than those luted with conventional Glass-Ionomer and Zinc Phosphate cement. 4. The results indicated that all five luting systems yielded comparable and acceptable marginal fit.

• Journal of Dental Rehabilitation and Applied Science
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• v.33 no.4
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• pp.291-298
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• 2017

It is challenging to produce esthetic implant restoration in the narrow anterior maxilla region where insufficient volume of alveolar bone could limit the angle and position of implant fixture, if preceding bone augmentation is not considered. Ideal angle and position of implant fixture placement should be established to reproduce harmonious emergence profile with marginal gingiva of implant prosthesis, bone augmentation considered to be preceded before implant placement occasionally. In this case, preceding bone augmentation has been operated before esthetic implant prosthesis in narrow anterior maxilla region. Preceded excessive bone augmentation in buccal area allowed proper angulation of implantation, which compensates unfavorable implant position. Provisional restorations were corrected during sufficient period to make harmonious level of marginal gingiva and interdental papilla. The definite restoration was fabricated using zirconia core based glass ceramic. Functionally and esthetically satisfactory results were obtained.

• The Journal of Korean Academy of Prosthodontics
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• v.49 no.3
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• pp.263-269
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• 2011

The digital impression technique has been developed for more precise restorations and convenient procedures in prosthodontic treatment compared to the conventional impression technique. Along with the utilization of CAD/CAM, the introduction of digital impression technique actualizes the digitalization of dental treatments. This case is to compare two different prostheses introducing each procedure in detail; one from CAD/CAM after taking digital impression and the other from the conventional technique. A 22-year-old female visited the clinic with the chief complaint of correction of discoloration and shape on maxillary right central incisor. Due to the trauma 8 years ago, the tooth was endodontically treated with post and resin core. The treatment was planned and the procedures were conducted under the patient's consent to treat the tooth with all ceramic crowns in two different ways for comparison. In conclusion, both prostheses presented clinically acceptable results with comparing the internal fitness of two all ceramic crowns. The prosthesis from digital impression, however, showed more errors in respect of internal fitness.

• The Journal of Korean Academy of Prosthodontics
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• v.28 no.2
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• pp.53-76
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• 1990

The purpose of this study was to evaluate the tensile bond strength of adhesive resins to successively recast Rexillium III and Degudent-U. Recasting was done 4times successively. Specimen $A_1$, were cast by new metal, and $A_2$ by surpus of $A_1$, $A_3$ by surplus of, $A_2$ $A_4$ by surplus of $A_3$, $A_5$ by surplus of $A_4$ plus 50% new metal. The types of surface treatment for resinbonded restoration in this experiment were electrolytic etching by OXY-ETCH(Oxy dental products, Inc., Hillside, New Jersey, U.S,A.), aluminum oxide blasting, anodic oxidation by EZ-OXISOR( Towagiken Co., Kyoto, Japan), electrotinplating by Kura Ace(Kuralay Co., Kyoto, Japan). Three kinds of cementing resin used in this study were Comspan(K.P. Cauil Co, Milford Delaware, U.S.A.), Super Bond C&B(Sun-Medical Co. Ltd., Kyoto,Japan), Panavia EX(Kuralay Co., Ltd., Osaka, Japan). Tensile bond strength was measured by Instron Universal testing machineModel 1125) and all the specimen were observed with SEM(JEOL, JSM-T2000) and mode of bond failure were recorded. The obtained results were as follows : 1. In electrolytic etched group, tensile bond strength was decreassed when recast alloy was used, and tensile bond strength of Compan and panavia EX were not significantly different(P>0.05). 2. In remaining group treated by aluminum oxide blasting, EZ-OXIOR, Kura Ace, tensile bond strength were not changed when recast alloy were used, and tensile bond strength of SuperBond(C&B and Panavia EX were not significantly different(P>0.05). 3. IN SEM evaluation, electrolytic etched group and electrotinplated group exhibited different image when recast alloy was used, and remaining groups treated by aluminum oxide blasting, EZ-OXISOR exhibited the same. 4. IN observation of bond failure, electrolytic etched group exhibited adhesive failure and remaing groups treated by aluminium oxid blasting, EZ-OXISOR, Kura Ace exhibited adhesive and cohesive failure.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.1
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• pp.47-53
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• 2003

This study evaluated the influence of chemomechanical caries removal agent $Carisolv^{TM}$(MediTeam, Sweden) for composite resin adhesion to sound human permanent and primary dentin. The buccal/labial surfaces of 80 permanent molars and 80 primary incisors were used. Four types of adhesives and one composite resin were used; AQ Bond(Sun Medical, Japan), Clearfil SE Bond(Kuraray, Japan), Single Bond(3M, USA), Scotchbond Multi-Purpose(3M, USA) and Z100(3M, USA). One drop of $Carisolv^{TM}$(MediTeam, Sweden) was pretreated on the dentin for 0 second(control) and 60 seconds. The specimens were thermocycled for 1,000 times in baths kept 5 degrees C and 55 degrees C with a 30 seconds dwell time. Shear bond strengths were tested and the data was statistically analyzed using one-way ANOVA with subsequent post hoc Scheffe test at p<0.05. $Carisolv^{TM}$ treatment significantly decreased the shear bond strength. Shear bond strength of permanent dentin was significantly higher than that of primary dentin. Clearfil SE Bond treatment groups showed the highest shear bond strength and AQ Bond treatment groups showed the lowest shear bond strength.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.2
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• pp.204-209
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• 2003

A 9-year old boy visited Department of Pediatric dentistry, Chonbuk National University Hospital due to unstable occlusion. He had permanent 1st molars destructed severely by dental caries and lost vertical stop. He could not occlude in the same position on closing of the jaw since he could not find his centric occlusion. The treatment plan was made, which was oral rehabilitation with crown restorations on permanent 1st molars based on clinical and radiographic examinations and centric relation of the jaw. Treatment plan consisted of endodontic treatment, crown lengthening and restoration of the occlusal vertical dimension (OVD) with gold crown by 3mm-increase of OVD. After endodontic and periodontal treatments, temporary crowns made of acrylic resin were set for assessment of tolerance to an increased OVD. After a month for tolerance, final prosthetics were made and set temporarily. In a month, gold crowns were set finally. Immediately after setting, the patient showed anterior open bite, but at the appointment after 4 months, he showed normal overjet, overbite and stable occlusion.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.4
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• pp.601-606
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• 2009

Amelogenesis Imperfecta (AI) is a genetic disorder which retards the development of enamel and it can be classified into three types: hypoplastic, hypomaturation, hypocalcified type. This can occur both in deciduous and permanent dentition. A 8 year 8 month old patient with a chief complaints of delayed eruption on upper anteriors, calculus deposit on lower anteriors and anterior openbite visited the clinic. Anteriors had thin layer of enamel and were very narrow. Especially lower anteriors had rough surface and were in bad shape. Teeth were very hypersensitive to thermal changes. Upper and lower first molars showed severe attrition on the occlusal surface. Radiographs also verified hypoplastic enamel in the whole dentition including the teeth in the tooth bud. The patient was diagnosed as hypoplastic AI, and is being treated at the pediathc and prosthodontic department of the Kyunghee dental university hospital. To improve the function, esthetics, hypersensitivity of the AI patients, restorations on the posteriors and the anteriors with oral hygiene instruction are necessary, Constant follow-up check is needed until full growth and after full growth, cooperative care with the other department is needed.

• The korean journal of orthodontics
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• v.12 no.2
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• pp.145-154
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• 1982

Plaster models were constructed and orthopantomographs were taken for 86 male and 70 female primary school pupils, whose upper and lower permanent 4 incisors and 1st molars were completely erupted without crowding; whose deciduous canines and molars were found almost uniformly even without any visible tooth fractures, dental caries or restorations on proximal surfaces of the teeth. Certain reference points on the orthophantomograph were set up and measured and the values were compared with actual or predicted values from the models. The following results were obtained: 1. In regards to available space, the values from the orthopantomograph were greater than the values from the models by a mean of 3.24% on the upper and 10.06% on the lower for males; 3.05% on the upper and 10.01% on the lower for females. 2. In regards to total mesiodistal widths of permanent canine, 1st and 2nd premolars, the values from the orthopantomograph were greater than the presumed values based on the size of lower permanent 4 incisors from the models by a mean of 18.50% on the upper and 24.09% on the lower for males; 14.54 on the upper and 20.51% on the lower for females. 3. Comparing the magnified values of total mesiodistal widths of permanent canine, 1st and 2nd premolars with those of available space, the regression constants of regression equation (Y = a + bX) between them were a=3.2336, b=0.6533 on the upper and a=5.0138, b=0.3290 on the lower for males; a=2.5994, b=0.6521 on the upper and a=3.0113, b=0.6586 on the lower for females. 4. The correlation coefficients between the magnified values of available space and permanent canine, 1st and 2nd premolars were moderately positive as 0.6474 in the upper and 0.505 on the lower for males; 0.6493 on the upper and 0.6183 on the lower for females. 5. In regards to magnified values of the available space from the orthopantomographs there were no significant difference between sexes, (P>0.05) but of the total mesiodistal widths of permanent canine, 1st and 2nd premolars, a significant difference between sexes was found.(p<0.01).

• The Journal of Korean Academy of Prosthodontics
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• v.36 no.2
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• pp.245-257
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• 1998

This study was performed to measure the changes of the mandibular movement and the masticatory muscular activities - anterior temporal and masseter muscle of both side - reflected by intentional increase of anterior guidance angie. For this study, 5 volunteers (3 males and 2 females with average age of 24.0) were selected. Each volunteer had Angle's classification I and did not have any missing tooth except third molar and any extensive restorations. Metallic guide plate was made at volunteer's working model fabricated by improved dental stone and cemented to the palatal surface of maxillary central incisor using resin cement(Panavia $21^{(R)}$) and then adjusted not to give any occlusal interferences at intercuspal position. The activity of masticatory muscles and the changes of mandibular movement were recorded by EMG and Sirognathograph in Biopak analysing system(Bioresearch Inc., Milwaukee, Wisconsin, USA). Measurement was done at before experiment, immediatley after placement, 1 week after placement, immediately after removal, and 1 week after removal. The results were as follows: 1. Moderate phonetic disturbance and mild headache were occured to 3 volunteers for 2 days after setting and 1 volunteer had positive reaction to percussion and slight midline diastema. But all of these clinical signs were diappeared 1 week after removal and the other volunteer did not have any special clinical sign. 2. In the EMG of the mandibular rest position, the mean value of anterior tempotal muscle was increased immediately after placement(p<0.01) and then decreased 1 week after placement(p<0.05) and increased 1 week after removal(p<0.05) but not recovered as before experiment. The mean value of masseter muscle was decreased during the experiment period. 3. In the EMG during mandibular protrusive movement, all muscular activity was decreased during the experiment period. Reduced activity was not recovered 1 week after removal(p<0.03). 4. During the habitual opening, anteroposterior movement of mandible was decreased immediately after placement(p<0.05) and then increased 1 week after placement but not statistically significant(p>0.1). Vertical movement was not shown significant difference during the experiment period(p>0.1). Lateral movement was decreased immediately after placement(p<0.05) and then increased 1 week after placement but not recovered as before experiment. The opening and closing velocity of mandible was shown minor changes but not statistically significant. 5. During the habitual opening, anteroposterior movement of mandible was decreased 1 week after placement(p<0.05) and then increased immediately after removal and recovered 1 week after removal as before experiment. Vertical movement was not shown significant changes. Lateral displacement of mandible was increased continuously and recovered 1 week after removal. Opening velocity was temporarily increased immediately after removal but recovered and closing velocity was not shown significant changes. 6. During the right side chewing, anteroposterior movement of mandible was increased immediately after removal but recovered and vertical movement was not shown statistically significant results. Lateral displacement and velocity of mandible were not shown significant results. 7. During the left side chewing, the changes of mandibular movement pattern were not shown statistically significant results.

• Journal of Dental Rehabilitation and Applied Science
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• v.22 no.3
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• pp.221-230
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• 2006

Recently, the need for esthetic results has increased the interest for all-ceramic crown prosthesis. Furthermore, the development of zirconium core via CAD/CAM system has allowed the all ceramic restorations to be applied to almost all fixed prosthesis situations. But, the increased strength has been reported to increase in proportion with the bond strength of cement, and recently, the tribochemical system which increases the bond strength through, silica coating and silanization has been introduced. The purpose of this study was to compare the $Rocatec^{TM}$ system and $CoJet^{TM}$ system with the traditional acid etching and silanization method of the irconium based ceramic. The surface character was observed via SEM(X2000), and the bond strength with the resin cement were measured. 50 In-Ceram Zirconia (Adens, Korea) discs were fabricated and embedded in resin, group 1 was treated with glass-bead blasting and cleaning, group 2 was treated with 20% HF for 10 minutes and silanized, group 3 was treated with the $Rocatec^{TM}$ system, and group 4 was treated with the $CoJet^{TM}$ system. Each group was comprised of 10 specimens. The specimens were cemented to a $3mm{\times}5mm$ resin block with Super-Bond C&B. The shear bond strength was measured with the $Instron^{(R)}$ 8871 at a crosshead speed of 0.5mm/min. The results were as follows. 1. According to SEM results, there were little difference between group 1 & group 2, but in group 3 and 4, silica coating was detected and there was increase in surface roughness. 2. The shear bond strength decreased in the order of group 3(46.28MPa), group 4(42.04MPa), group 2(31.56MPa), and group 1(27.46MPa). 3. There was significant differnce between group 1&2 and group 3&4(p<0.05). From the results above, it can be considered that the conventional method of acid etching and silane treatment cannot increase the bond strength with resin cements, and that by applying the tribochemical system of $Rocatec^{TM}$ system and $CoJet^{TM}$ system, we can achieve a stronger all ceramic restoration. Further studies on surface treatments to increase the bond strength are thought to be needed.