OBJECTIVES: The aim of this study was to evaluate the surface color of indirect resin restoration according to the layering placement of different shade of incisal composite. MATERIALS AND METHODS: In this study, CIE L*a*b* value of 16 Body composite of Tescera ATL (Bisco, Schaumburg IL,USA) was measured by spectrophotometer (NF999, Nippon Denshuku, Japan), and compared to CIE L*a*b* value of Vitapan shade guide. Nine shade Incisal composite of Tescera ATL were build-up to 1 mm thickness on Body composites inlay block, and CIE L*a*b* value was measured. Incisal composite was ground to 0.5 mm thickness and CIE L*a*b* value was re-measured. Color difference between Body composite and Incisal composites layered on Body composite was calculated as a function of thickness. RESULTS: Color difference between corresponding shade of Tescera Body composite and Vitapan shade guide was from 6.88 to 12.80. L* and b*value was decreased as layering thickness of Incisal composite on Body composite was increased. But, a* value did not show specific change tendency. CONCLUSIONS: Surface color difference between Body composites and Incisal composites layered on Body composite was increased as the layering thickness of Incisal composite increased (p < 0.05).
Composite Resins ; Inlays

OBJECTIVES: In the present study, three kinds of tissues cells (pulp, gingiva, and periodontal ligament) were investigated if those cells express MMP and TIMP when they were stimulated with neuropeptides (substance P, CGRP) or proinflammatory cytokine, TNF-alpha. MATERIALS AND METHODS: The cells cultured from human dental pulp (PF), gingiva (GF) and periodontal ligament were (PDLF) stimulated with Mock, SP, TNF-alpha, and CGRP for 24 hrs and 48 hrs. for an RNase protection assay and Enzyme Linked Immunosorbent Assay. Cells (PF, GF and PDLF) seeded in 100 mm culture dish were stimulated with SP (10(-5), 10(-8) M) or only with medium (Mock stimulation) for 4hrs and for 24 hrs for RNase Protection Assay, and they were stimulated with CGRP (10(-5) M) and TNF-alpha (2 ng/mL) for 24 hrs and with various concentraion of TNF-alpha (2, 10, and 100 ng/mL) for Rnase Protection Assay with a human MMP-1 probe set including MMP 1, 2, 8, 7, 8, 9, 12, and TIMP 2, 3. In addition, cells (PF, GF and PDLF) were stimulated with Mock and various concentraion of TNF-alpha(2, 10, and 100 ng/mL) for 24 hrs and with TNF-alpha(10 ng/mL) for 48 hrs, and the supernatents from the cells were collected for Enzyme Linked Immunosorbent Assay (ELISA) for MMP-1 and MMP-13. RESULTS: The expression of MMPs in PF, GF, PDLF after stimulation with SP and CGRP were not changed compared with Mock stimulation for 4 hrs and 24 hrs. The expression of MMP-1, -12, -13 24 hrs after stimulation with TNF-alpha were upregulated, however the expression of TIMP-3 in PF, GF, PDLF after stimulation with TNF-alpha were downregulated. TNF-alpha (2 ng/mL, 10 ng/mL, 100 ng/mL) increased MMP-1 and MMP-12 expression in PF dose dependently for 24 hrs. CONCLUSIONS: TNF-alpha in the area of inflammation may play an important role in regulating the remodeling of dentin, cementum, and alveolar bone.
Dental Cementum ; Dental Pulp ; Dentin ; Enzyme-Linked Immunosorbent Assay ; Gingiva ; Humans ; Inflammation ; Matrix Metalloproteinases ; Neuropeptides ; Periodontal Ligament ; Ribonucleases ; Seeds ; Substance P ; Tissue Inhibitor of Metalloproteinase-3 ; Tumor Necrosis Factor-alpha

OBJECTIVES: The purpose of this retrospective study was to evaluate the success rate of intentionally replanted mandibular second molar with C-shaped canal configurations and to access the impact of preoperative periapical lesion on the success of intentional replantation procedure. MATERIALS AND METHODS: This retrospective chart review study evaluated 52 intentionally replanted mandibular second molar teeth treated at Seoul National University Dental Hospital Department of Conservative Dentistry from January 2005 to December 2007. Seventeen teeth were lost for the follow-up, and another 6 teeth did not meet inclusion criteria of C-shaped root canal configurations. Healing outcome such as success, uncertain healing, and failure after follow-up was evaluated by clinical criteria and radiographs. RESULTS: The overall success rate was 72.4% for the 29 intentionally replanted C-shaped mandibular second molars. The success rate of replanted teeth with preoperative periapical lesions was similar to that of replanted teeth which have no periapical lesions. CONCLUSIONS: Therefore, root canal treatment failure on C-shaped mandibular second molar can be predictably treated by intentional replantation regardless of the presence of periapical lesion.
Dental Pulp Cavity ; Dentistry ; Follow-Up Studies ; Hospital Departments ; Intention ; Molar ; Replantation ; Retrospective Studies ; Tooth ; Treatment Failure

OBJECTIVES: This retrospective study evaluated the therapeutic effects of the intentional replantation (IR) procedure performed on the maxillary and mandibular molars of 35 patients. MATERIALS AND METHODS: For the subjects, IR was performed due to difficulties in anatomically accessing the lesions and/or close proximity to the thick cortical bone, inferior alveolar nerve, or maxillary sinus, which rendered the ordinary periradicular surgery impossible. The patients' progress was followed for a year and up to 2 years and 4 months. The success of the procedure was evaluated in terms of clinical and radiographic success (%). RESULTS: The results revealed the following: (a) 1 case (3%) of failed tooth extraction during IR; (b) 2 cases (6%) of extraction due to periodontal diseases and inflammatory root resorption; (c) 3 cases (9%) of normally functioning teeth in the oral cavity with minor mobility and apical root resorption, and; (d) 29 cases (82%) of normally functioning teeth without obvious problems. CONCLUSIONS: IR was confirmed to be a reliably repeatable, predictable treatment option for those who cannot receive conventional periradicular surgery because of anatomic limitations or patient factors.
Humans ; Intention ; Mandibular Nerve ; Maxillary Sinus ; Molar ; Mouth ; Periodontal Diseases ; Replantation ; Retrospective Studies ; Root Resorption ; Tooth ; Tooth Extraction

INTRODUCTION: The aim of this paper is to discuss the mechanical and geometric features of Nickel-titanium (NiTi) rotary files and its clinical effects. NiTi rotary files have been introduced to the markets with their own geometries and claims that they have better ability for the root canal shaping than their competitors. The contents of this paper include the (possible) interrelationship between the geometries of NiTi file (eg. tip, taper, helical angle, etc) and clinical performance of the files as follows; - Fracture modes of NiTi rotary files - Non-cutting guiding tip and glide path - Taper and clinical effects - Cross-sectional area and clinical effects - Heat treatments and surface characteristics - Screw-in effect and preservation of root dentin integrity - Designs for reducing screw-in effect CONCLUSIONS: Based on the reviewed contents, clinicians may have an advice to use various brands of NiTi rotary instruments regarding their advantages which would fit for clinical situation.
Dental Pulp Cavity ; Dentin ; Hot Temperature

As the dental pulp is encased with a rigid, noncompliant shell, changes in pulpal blood flow or vascular tissue pressure can have serious implication for the health of pulp. Numerous studies have demonstrated that orthodontic force application may influence both blood flow and cellular metabolism, leading degenerative and/or inflammatory responses in the dental pulp. The aim of this case report is to present a case about tooth with chronic periapical abscess which showed normal vital responses. Excessive orthodontic force is thought to be the prime cause of partial pulp necrosis. Owing to remaining vital tissue, wrong dianosis can be made, and tooth falsely diagnosed as vital may be left untreated, causing the necrotic tissue to destroy the supporting tissuses. Clinician should be able to utilize various diagnostic tools for the precise diagnosis, and be aware of the endodontic-orthodontic inter-relationship.
Dental Pulp ; Dental Pulp Necrosis ; Periapical Abscess ; Tooth

OBJECTIVES: This study investigated the effect of the strength and wetting characteristics of adhesives on the bond strength to dentin. The experimental adhesives containing various ratios of hydrophobic, low-viscosity Bis-M-GMA, with Bis-GMA and TEGDMA, were made and evaluated on the mechanical properties and bond strength to dentin. MATERIALS AND METHODS: Five experimental adhesives formulated with various Bis-GMA/Bis-M-GMA/TEGDMA ratios were evaluated on their viscosity, degree of conversion (DC), flexural strength (FS), and microtensile bond strength (MTBS). The bonded interfaces were evaluated with SEM and the solubility parameter was calculated to understand the wetting characteristics of the adhesives. RESULTS: Although there were no significant differences in the DC between the experimental adhesives at 48 hr after curing (p > 0.05), the experimental adhesives that did not contain Bis-GMA exhibited a lower FS than did those containing Bis-GMA (p < 0.05). The experimental adhesives that had very little to no TEGDMA showed significantly lower MTBS than did those containing a higher content of TEGDMA (p < 0.05). The formers exhibited gaps at the interface between the adhesive layer and the hybrid layer. The solubility parameter of TEGDMA approximated those of the components of the primed dentin, rather than Bis-GMA and Bis-M-GMA. CONCLUSIONS: To achieve a good dentin bond, a strong base monomer, such as Bis-GMA, cannot be completely replaced by Bis-M-GMA for maintaining mechanical strength. For compatible copolymerization between the adhesive and the primed dentin as well as dense cross-linking of the adhesive layer, at least 30% fraction of TEGDMA is also needed.
Adhesives ; Benzhydryl Compounds ; Bisphenol A-Glycidyl Methacrylate ; Chimera ; Dentin ; Methacrylates ; Polyethylene Glycols ; Polymethacrylic Acids ; Solubility ; Viscosity

OBJECTIVES: The purpose of this study was to evaluate curing degree of three dual-cure resin cements with the elapsed time in self-cure and dual-cure mode by means of the repeated measure of micro-hardness. MATERIALS AND METHODS: Two dual-cure self-adhesive resin cements studied were Maxcem Elite (Kerr), Rely-X Unicem (3M ESPE) and one conventional dual-cure resin cement was Rely-X ARC resin cement (3M ESPE). Twenty specimens for each cements were made in Teflon mould and divided equally by self-cure and dual-cure mode and left in dark, 36degrees C, 100% relative humidity conditional-micro-hardness was measured at 10 min, 30 min, 1 hr, 3 hr, 6 hr, 12 hr and 24 hr after baseline. The results of micro-hardness value were statistically analyzed using independent samples t-test and one-way ANOVA with multiple comparisons using Scheffe's test. RESULTS: The micro-hardness values were increased with time in every test groups. Dual-cure mode obtained higher micro-hardness value than self-cure mode except after one hour of Maxcem. Self-cured Rely-X Unicem showed lowest value and dual-cured Rely-X Unicem showed highest value in every measuring time. CONCLUSIONS: Sufficient light curing to dual-cure resin cements should provided for achieve maximum curing.
Humidity ; Light ; Polytetrafluoroethylene ; Resin Cements

OBJECTIVES: The purpose of this study was to evaluate the effect of surface treatment of FRC-Post on bonding strength to resin cements. MATERIALS AND METHODS: Pre-surface treated LuxaPost (DMG), Rely-X Fiber Post (3M ESPE) and self adhesive resin cement Rely-X Unicem (3M ESPE), conventional resin cement Rely-X ARC (3M ESPE), and Rely-X Ceramic Primer (3M ESPE) were used. After completing the surface treatments of the posts, posts and resin cement were placed in clear molds and photo-activation was performed. The specimens were sectioned perpendicular to the FRC-Post into 2 mm-thick segments, and push-out strength were measured. The results of bond strength value were statistically analyzed using independent samples t-test and one-way ANOVA with multiple comparisons using Scheffe's test. RESULTS: Silanization of posts affect to the bond strength in LuxaPost, and did not affect in Rely-X Fiber Post. Rely-X ARC showed higher value than Rely-X Unicem. CONCLUSIONS: Silanization is needed to enhance the bond strength between LuxaPost and resin cements.
Adhesives ; Ceramics ; Fungi ; Resin Cements

OBJECTIVES: The purpose of this experiment was to evaluate four different polishing systems of their polishability and polishing time. MATERIALS AND METHODS: 4 mm diameter and 2 mm thickness Teflon mold was made. Z-250 (3M ESPE) hybrid composite resin was slightly overfilled and pressed with slide glass and cured with Optilux 501 for 40 sec each side. Then the surface roughness (glass pressed: control group) was measured with profilometer. One surface of the specimen was roughened by #320 grit sand paper and polished with one of the following polishing systems; Sof-Lex (3M ESPE), Jiffy (Ultradent), Enhance (Dentsply/Caulk), or Pogo (Dentsply/Caulk). The surface roughness and the total polishing time were measured. The results were analyzed with one-way ANOVA and Duncan's multiple range test. RESULTS: The surface roughness was lowest in Pogo, and highest in Sof-Lex. Polishing times were shortest with Pogo, and followed by the Sof-Lex, Enhance and Jiffy. CONCLUSIONS: One-step polishing system (Pogo) is very effective to get the smooth surface in a short time, therefore it can be recommended for final polishing system of the restoration.
Chimera ; Fungi ; Glass ; Polytetrafluoroethylene ; Silicon Dioxide