• Title/Summary/Keyword: Occlusal analysis

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수종의 상아질 접착제와 복합레진의 적합성에 관한 연구 (A STUDY ON THE COMPATIBILITY OF DENTIN ADHESIVES WITH COMPOSITE RESINS)

  • 박진성;권혁춘
    • Restorative Dentistry and Endodontics
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    • 제20권1호
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    • pp.214-234
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    • 1995
  • The purpose of this work was to study the compatibility of several commercially available dentin adhesives with composite resins. In this study, V-shaped cavity preparations were created on both buccal and lingual surfaces of 60 extracted human premolars($3mm{\times}3mm{\times}2mm$ deep). Preparations were located such that the occlusal margins were on the enamel and the gingival margins were on the cementum(1mm below the CEJ). These specimens were randomly divided into three equal groups. Three dentin adhesives(Scotchbond Multi-Purpose, All Bond 2, Prisma Universal Bond 3)were applied to the cavity in accordance with each manufacturer's instructions. The teeth in each group were restored with four composite resins(Silux plus, Z100, Bisfil, Prisma TPH) in three increments, with each increment light-cured for 40 seconds. All specimens were exposed to 500 cycles of thermal stress. Specimens then placed in a silver nitrate solution(50% by weight) and stored in darkness for 24 hours. They were then immersed for 6 hours in photographic developing solution under flourescent light. Specimens were sectioned buccolingually through the center of the restoration and observed under a binocular stereoscope. To compare the marginal leakage, ANOVA and Dunkan's multiple range tests were used in analysis. Selected samples were further studied using scanning electron microscopy(XL20, Philips, The Netherlands). The results were as follows. 1. In all groups, the enamel margin showed significantly less leakage than the cementum margin. 2. No statistically significant differences were found in microleakage when composite resins were used with their proprietary dentin adhesives. 3. In comparison between dentin adhesives, Prisma Universal Bond 3 showed significantly less leakage at the enamel margin and Scotch bond multi-purpose showed significantly less leakage at the cementum margin than the other groups. 4. In comparison between composite resins, Silux Plus showed significantly more leakage than other groups at the enamel margin and no statistically significant differences were found in microleakage at the cementum margin. 5. According to the backscattered scanning electron microscope, microleakage occurred via gaps at the dentin adhesives/dentin interface.

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Comparative efficacy of photo-activated disinfection and calcium hydroxide for disinfection of remaining carious dentin in deep cavities: a clinical study

  • Sharma, Sidhartha;Logani, Ajay;Shah, Naseem
    • Restorative Dentistry and Endodontics
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    • 제39권3호
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    • pp.195-200
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    • 2014
  • Objectives: To comparatively evaluate the efficacy of photo-activated disinfection (PAD), calcium hydroxide (CH) and their combination on the treatment outcome of indirect pulp treatment (IPT). Materials and Methods: Institutional ethical clearance and informed consent of the patients were taken. The study was also registered with clinical registry of India. Sixty permanent molars exhibiting deep occlusal carious lesion in patients with the age range of 18 - 22 yr were included. Clinical and radiographic evaluation and set inclusion and exclusion criteria's were followed. Gross caries excavation was accomplished. In group I (n = 20) PAD was applied for sixty seconds. In group II (n = 20), CH was applied to the remaining carious dentin, while in group III (n = 20), PAD application was followed by CH placement. The teeth were permanently restored. They were clinically and radiographically followed-up at 45 day, 6 mon and 12 mon. Relative density of the remaining affected dentin was measured by 'Radiovisiography (RVG) densitometric' analysis. Results: Successful outcome with an increase in radiographic grey values were observed in all three groups. However, on inter-group comparison, this change was not significant (p > 0.05). Conclusions: PAD and CH both have equal disinfection efficacy in the treatment of deep carious dentin. PAD alone is as effective for treatment of deep carious lesion as calcium hydroxide and hence can be used as an alternative to CH. They can be used independently in IPT, since combining both does not offer any additional therapeutic benefits.

Image analysis of the eruptive positions of third molars and adjacent second molars as indicators of age evaluation in Thai patients

  • Mahasantipiya, Phattaranant May;Pramojanee, Sakarat;Thaiupathump, Trasapong
    • Imaging Science in Dentistry
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    • 제43권4호
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    • pp.289-293
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    • 2013
  • Purpose: This study was performed to determine the relationship between the stage of tooth eruption (both vertical and mesio-angular) and chronological age. Materials and Methods: Indirect digital panoramic radiographs were used to measure the distances from the dentinoenamel junction (DEJ) of the second molars to the occlusal plane of the second molar teeth and of the adjacent third molars in 264 Thai males and 437 Thai females using ImageJ software. The ratio of those distances was calculated by patient age, and the correlation coefficient of the ratio of the third molar length to the second molar length was calculated. Results: The correlation between the height of the vertically erupted upper third molar teeth and age was at the intermediate level. The age range of ${\geq}15$ to <16 years was noted to be the range in which the correlation between the chronological age determined from the eruptional height and actual chronological age was statistically significant. The mean age of the female subjects, in which the position of the right upper third molar teeth was at or above the DEJ of the adjacent second molar but below one half of its coronal height was $19.9{\pm}2.6$ years. That for the left side was $20.2{\pm}2.7$ years. The mean ages of the male subjects were $20.1{\pm}3.3$ years and $19.8{\pm}2.7$ years for the right and left sides, respectively. Conclusion: It might be possible to predict chronological age from the eruption height of the wisdom teeth.

Comparison of effect of desensitizing agents on the retention of crowns cemented with luting agents: an in vitro study

  • Jalandar, Sonune Shital;Pandharinath, Dange Shankar;Arun, Khalikar;Smita, Vaidya
    • The Journal of Advanced Prosthodontics
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    • 제4권3호
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    • pp.127-133
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    • 2012
  • PURPOSE. Many dentists use desensitizing agents to prevent hypersensitivity. This study compared and evaluated the effect of two desensitizing agents on the retention of cast crowns when cemented with various luting agents. MATERIALS AND METHODS. Ninety freshly extracted human molars were prepared with flat occlusal surface, 6 degree taper and approximately 4 mm axial length. The prepared specimens were divided into 3 groups and each group is further divided into 3 subgroups. Desensitizing agents used were GC Tooth Mousse and $GLUMA^{(R)}$ desensitizer. Cementing agents used were zinc phosphate, glass ionomer and resin modified glass ionomer cement. Individual crowns with loop were made from base metal alloy. Desensitizing agents were applied before cementation of crowns except for control group. Under tensional force the crowns were removed using an automated universal testing machine. Statistical analysis included one-way ANOVA followed by Turkey-Kramer post hoc test at a preset alpha of 0.05. RESULTS. Resin modified glass ionomer cement exhibited the highest retentive strength and all dentin treatments resulted in significantly different retentive values (In Kg.): GLUMA ($49.02{\pm}3.32$) > Control ($48.61{\pm}3.54$) > Tooth mousse ($48.34{\pm}2.94$). Retentive strength for glass ionomer cement were GLUMA ($41.14{\pm}2.42$) > Tooth mousse ($40.32{\pm}3.89$) > Control ($39.09{\pm}2.80$). For zinc phosphate cement the retentive strength were lowest GLUMA ($27.92{\pm}3.20$) > Control ($27.69{\pm}3.39$) > Tooth mousse ($25.27{\pm}4.60$). CONCLUSION. The use of $GLUMA^{(R)}$ desensitizer has no effect on crown retention. GC Tooth Mousse does not affect the retentive ability of glass ionomer and resin modified glass ionomer cement, but it decreases the retentive ability of zinc phosphate cement.

Comparison of the fit accuracy of zirconia-based prostheses generated by two CAD/CAM systems

  • Ha, Seok-Joon;Cho, Jin-Hyun
    • The Journal of Advanced Prosthodontics
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    • 제8권6호
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    • pp.439-448
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    • 2016
  • PURPOSE. The purposes of this study are to evaluate the internal and marginal adaptation of two widely used CAD/CAM systems and to study the effect of porcelain press veneering process on the prosthesis adaptation. MATERIALS AND METHODS. Molar of a lower jaw typodont resin model was prepared by adjusting a 1.0 mm circumferential chamfer, an occlusal reduction of 2.0 mm, and a $5^{\circ}$ convergence angle and was duplicated as an abrasion-resistant master die. The monolithic crowns and copings were fabricated with two different CAD/CAM system-Ceramil and Zirkonzahn systems. Two kinds of non-destructive analysis methods are used in this study. First, weight technique was used to determine the overall fitting accuracy. And, to evaluate internal and marginal fit of specific part, replica technique procedures were performed. RESULTS. The silicone weight for the cement space of monolithic crowns and copings manufactured with Ceramil system was significantly higher than that from Zirkonzahn system. This gap might cause the differences in the silicone weight because the prostheses were manufactured according to the recommendation of each system. Marginal discrepancies of copings made with Ceramil system were between 106 and $117{\mu}m$ and those from Zirkonzahn system were between 111 and $115{\mu}m$. Marginal discrepancies of copings made with Ceramil system were between 101 and $131{\mu}m$ and those from Zirkonzahn system were between 116 and $131{\mu}m$. CONCLUSION. Marginal discrepancy was relatively lower in Ceramil system and internal gap was smaller in Zirkonzahn system. There were significant differences in the internal gap of monolithic crown and coping among the 2 CAD/CAM systems. Marginal discrepancy produced from the 2 CAD/CAM systems were within a reported clinically acceptable range of marginal discrepancy.

심한 우식을 동반한 골격성 전치부 개방 교합 환자의 전악 수복 증례 (Full-mouth rehabilitation of skeletal anterior open bite with severely decayed dentition: A case report)

  • 김성아;노관태;배아란;우이형
    • 대한치과보철학회지
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    • 제55권1호
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    • pp.79-87
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    • 2017
  • 전치부 개방 교합은 다양한 원인이 복합적으로 작용하고, 진단에 따라 효과적인 치료 계획과 적절한 유지 방법을 선택할 수 있다. 대부분의 경우 교정과 악교정 수술을 통해 안정적인 교합을 얻고, 기능과 심미를 회복한다. 하지만 전체 치열에서 심한 우식증이 있는 경우 광범위한 수복이 필요하게 되므로, 보철 수복을 통해서도 교합을 재형성할 수 있다. 본 증례는 심한 우식을 동반한 골격성 전치부 개방 교합 환자에서 안모 분석 및 진단 납형으로부터 가장 효과적인 치료로 전악 보철 수복을 선택하였다. 교합력을 균등하게 분산하고 심미적인 임시 수복물을 제작하였고, 악간 관계 평가, 혀 등 연조직의 적응, 입술과의 조화를 관찰하고 수정하였다. 충분한 기간 동안 사용한 임시 수복물을 CAD/CAM (Computer-aided design/computer-aided manufacturing)을 이용하여 단일구조 지르코니아 최종 보철물로 이행하였고, 치료 종결 후 3개월 간 주기적으로 관찰하였을 때 만족스러운 결과를 얻었다.

Influence of preparation design on fracture resistance of different monolithic zirconia crowns: A comparative study

  • Findakly, Meelad Basil;Jasim, Haider Hasan
    • The Journal of Advanced Prosthodontics
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    • 제11권6호
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    • pp.324-330
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    • 2019
  • PURPOSE. The aim of the study was to evaluate and compare the fracture resistance and modes of fracture of monolithic zirconia crowns with two preparation designs. MATERIALS AND METHODS. Forty human maxillary first premolar teeth were extracted for orthodontic purposes and divided into two main groups (n=20): Group A: monolithic traditional zirconia; Group B: monolithic translucent zirconia. The groups were further subdivided into two subgroups (n=10): (A1, B1) shoulder margin design; (A2, B2) feather-edge margin design. Teeth were prepared with either a 1 mm shoulder margin design or a feather-edge margin design. The prepared teeth were scanned using a digital intraoral scanner. The crowns were cemented using self-adhesive resin cement. All cemented teeth were stored in water for 7 days and thermocycling was done before testing. All samples were subjected to compressive axial loading until fracture. The fractographic analysis was done to assess the modes of fracture of the tested samples. RESULTS. The highest mean values of fracture resistance were recorded in kilo-newton and were in the order of subgroup A1 (2.903); subgroup A2 (2.3); subgroup B1 (1.854) and subgroup B2 (1.523). One-way ANOVA showed a statistically significant difference among the 4 subgroups. Concerning modes of fracture, the majority of samples in subgroups A1 and B1 were fracture of restoration and/or tooth, while in subgroups A2 and B2, the majority of samples fractured through the central fossa. CONCLUSION. Even though all the tested crowns fractured at a higher level than the maximum occlusal forces, the shoulder margin design was better than the feather-edge margin design and the monolithic traditional zirconia was better than the monolithic translucent zirconia in terms of fracture strength.

Comparison of fracture strength after thermomechanical aging between provisional crowns made with CAD/CAM and conventional method

  • Reeponmaha, Tanapon;Angwaravong, Onauma;Angwarawong, Thidarat
    • The Journal of Advanced Prosthodontics
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    • 제12권4호
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    • pp.218-224
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    • 2020
  • PURPOSE. The objectives of this study were to evaluate the fracture strength and fracture patterns of provisional crowns fabricated from different materials and techniques after receiving stress from a simulated oral condition. MATERIALS AND METHODS. A monomethacrylate-based resin (Unifast Trad) and a bis-acryl-based (Protemp 4) resin were used to fabricate provisional crowns using conventional direct technique. A milled monomethacrylate resin (Brylic Solid) and a 3D-printed bis-acrylate resin (Freeprint Temp) were chosen to fabricate provisional crowns using the CAD/CAM process. All cemented provisional crowns (n=10/group) were subjected to thermal cycling (5,000 cycles at 5°-55℃) and cyclic occlusal load (100 N at 4 Hz for 100,000 cycles). Maximum force at fracture was tested using a universal testing machine. RESULTS. Maximum force at fracture (mean ± SD, N) of each group was 657.87 ± 82.84 for Unifast Trad, 1125.94 ± 168.07 for Protemp4, 953.60 ± 58.88 for Brylic Solid, and 1004.19 ± 122.18 for Freeprint Temp. One-way ANOVA with Tamhane post hoc test showed that the fracture strength of Unifast Trad was statistically significantly lower than others (P<.01). No statistically significant difference was noted among other groups. For failure pattern analysis, Unifast Trad and Brylic Solid showed less damage than Protemp 4 and Freeprint Temp groups. CONCLUSION. Provisional crowns fabricated using the CAD/CAM process and the conventionally fabricated bis-acryl resins exhibited significant higher fracture strength compared to conventionally fabricated monomethacrylate resins after the aging regimen. Therefore, CAD/CAM milling and 3D printing of provisional restorations may be good alternatives for long term provisionalization.

제 5급 와동에서의 단일용기 상아질 접착제와 자가 산부식 접착제의 상아질에 대한 침투도 평가 (A CONFOCAL MICROSCOPIC STUDY ON DENTINAL INFILTRATION OF ONE-BOTTLE ADHESIVE SYSTEMS AND SELF-ETCHING PRIMING SYSTEM BONDED TO CLASS V CAVITIES)

  • 김형수;박성호
    • Restorative Dentistry and Endodontics
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    • 제27권3호
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    • pp.257-269
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    • 2002
  • Objective : The purpose of this study was to evaluate the resin infiltration into dentin of one-bottle adhesive systems and self-etching primer bonded to Class V cavities using confocal laser scanning microscope(CLSM). Material and Methods : Forty Class V cavities were prepared from freshly extracted caries-free Human teeth. These teeth were divided into two groups based on the presence of cervical abrasion: Group I, cervical abrasion : Group II, wedge-shaped cavity preparation. Resin-dentin interfaces were produced with two one-bottle dentin bonding systems-ONE COAT BOND(OCB; Coltene$^R$) and Syntac$^R$SPrint$^{TM}$(SS; VIVADENT)-, one self-etching priming system-CLEARFIL$^{TM}$ SE BOND (SB : KURARAY)- and one multi-step dentin bonding system-Scotchbond$^{TM}$Multi-Purpose (SBMP, 3M Dental Products)-as control according to manufacturers' instructions. Cavities were restored with Spectrum$^{R}$(Dentsply). Specimens were immersed in saline for 24 hours and sectioned longitudinally with a low-speed diamond disc. The resin-dentin interfaces were microscopically observed using CLSM. The quality of resin-infiltrated dentin layers were evaluated by five dentists using 0~4 scale. Results : Confocal laser scanning microscopal investigations using primer labeled with rhodamine B showed that the penetration of the primer occurred along the cavity margins. Statistical analysis using one-way ANOVA followed by Duncan's Multiple Range test revealed that the primer penetration of the group 2(wedge-shaped cavity preparation) was more effective than group 1(cervical abrasion) and that of the gingival interfaces was more effective than the occlusal interfaces. In the one-bottle dentin bonding systems, the resin penetration score of OCB was compatible to SBMP, but those of SS and self-etching priming system, SB were lower than SBMP.

II급 부정교합 치료 후 재발과 골격치성요소의 상관성 (Correlationship of skeletodental factors to a relapse in class II correctionn)

  • 정애진;이도훈;강경화;김상철
    • 대한치과교정학회지
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    • 제34권2호
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    • pp.153-163
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    • 2004
  • II급 부정교합 치료 후 일어나는 재발에 영향을 미치는 요소를 알아보기 위하여 치료 후 결과가 안정하게 유지된 군과 재발이 일어난 군으로 구분하여 골격 및 치성요소를 비교하였다. 치료 전과 치료 후 측모 두부방사선사진을 이용하여 t-test와 상관분석을 시행한 결과 다음과 같은 결론을 얻었다. 1. 안정군과 재발군 간에 치료 전 골격 및 치성 관계는 대체로 차이가 없었다. 2. 안정군에서 하악골의 전방성장이 더 많이 일어났다. 3. 안정군에서의 하악 전치는 더 직립되었으며 상악전치는 설측 경사가 적은 경향을 보였다. 4. 재발군에서 교합평면이 전하방으로 경사되는 경향을 보였다.