Non-surgical root canal treatment of maxillary second premolar fused paramolar tubercle

Paramolar tubercle is a rare developmental dental anomaly defined as an additional cusp occurring on the buccal or lingual sur-faces of the molar. Permanent molar fused with paramolar tubercles can be a cause of difficulty in root canal treatment. Therefore, proper understanding of these variations is important in order to ensure successful endodontic treatment. Cone beam computed tomography (CBCT) can be helpful to understand anatomy of complicated cases. This case report describes nonsurgical endodontictreatment of maxillary second premolar fused with paramolar tubercle.

Intentional replantation with preapplication of orthodontic force on mandibular second molar

Intentional replantation has been used for alternative treatment for conventional root canal therapy. This case report describes that the intentional replantation with application of extrusive orhodontic force for 6 weeks, on which tooth of previous root canal the-rapy. As preapplicatory orthodontic force, tooth moblity was increased so that extraction of the designated tooth was more easily accomplished and augmented volume of periodontal ligament is expected to acceleated gingival reattachment.

Color stability of esthetic restorative materials after application of fluoride varnishes / 대한치과재료학회지

The objective of present study was to compare the color stability of esthetic materials after application of fluoride varnishes. Esthetic restorative materials including composite resin (Filtek Z350 XT, 3M ESPE, MN, USA), resin modified glass-ionomer (RMGI, Fuji II LC, GC Co., Tokyo, Japan), and giomer (Beautifil Flow Plus F00, Shofu Inc., Kyoto, Japan) were used in this study. Cavity shield (3M ESPE, MN, USA) and V-varnish premium (Vericom, Seoul, Korea) were used as the fluoride varnishes. 30 samples of each restorative materials were prepared, which were divided into 10 each, among three groups. Group I were stored in distilled water, which were used as the control, Group II were applied with Cavity shield and Group III were applied with V-varnish premium. All specimens were stored in the distilled water at 60 ℃ for 30 days for the accelerated test. Samples were then subjected to colorimetric analysis. Data collected was statistically analyzed using one way ANOVA and Tukey's post-hoc test (p=0.05). The color change before and after application of varnish was observed in all experimental groups. Especially RMGI showed highest ΔE* value (p<0.05). The color change according to the accelerated test showed no significant difference in the varnish application group and the control group. Giomer and RMGI applied with Cavity shield showed more color change than V-varnish applied group, despite no significant differences. Present study concludes that color stability of esthetic restoration materials can be affected by application of fluoride varnish. Especially, RMGI showed a large color change compared to the composite resin and giomer, which suggested that careful attention should be paid to clinical application.

Color stability of esthetic restorative materials after application of fluoride varnishes / 대한치과재료학회지

The objective of present study was to compare the color stability of esthetic materials after application of fluoride varnishes. Esthetic restorative materials including composite resin (Filtek Z350 XT, 3M ESPE, MN, USA), resin modified glass-ionomer (RMGI, Fuji II LC, GC Co., Tokyo, Japan), and giomer (Beautifil Flow Plus F00, Shofu Inc., Kyoto, Japan) were used in this study. Cavity shield (3M ESPE, MN, USA) and V-varnish premium (Vericom, Seoul, Korea) were used as the fluoride varnishes. 30 samples of each restorative materials were prepared, which were divided into 10 each, among three groups. Group I were stored in distilled water, which were used as the control, Group II were applied with Cavity shield and Group III were applied with V-varnish premium. All specimens were stored in the distilled water at 60 ℃ for 30 days for the accelerated test. Samples were then subjected to colorimetric analysis. Data collected was statistically analyzed using one way ANOVA and Tukey's post-hoc test (p=0.05). The color change before and after application of varnish was observed in all experimental groups. Especially RMGI showed highest ΔE* value (p<0.05). The color change according to the accelerated test showed no significant difference in the varnish application group and the control group. Giomer and RMGI applied with Cavity shield showed more color change than V-varnish applied group, despite no significant differences. Present study concludes that color stability of esthetic restoration materials can be affected by application of fluoride varnish. Especially, RMGI showed a large color change compared to the composite resin and giomer, which suggested that careful attention should be paid to clinical application.

Conservative approach for anterior crown-root fractured teeth: forced eruption

In the case of crown-root fracture due to traumatic injury in anterior tooth and the fracture margin is located subgingivally,forced eruption has been proposed for the reconstruction of deficient bone and soft tissue. Forced eruption is one of the easiestorthodontic approaches that can have an acceptable outcome and prognosis, and has a low incidence of relapse. However, using heavy forces or very fast movements can also cause tissue damage or ankylosis. The following case reports present forced eruption as treatment option of crown fracture in maxillary anterior teeth.

Conservative approach for anterior crown-root fractured teeth: forced eruption

In the case of crown-root fracture due to traumatic injury in anterior tooth and the fracture margin is located subgingivally,forced eruption has been proposed for the reconstruction of deficient bone and soft tissue. Forced eruption is one of the easiestorthodontic approaches that can have an acceptable outcome and prognosis, and has a low incidence of relapse. However, using heavy forces or very fast movements can also cause tissue damage or ankylosis. The following case reports present forced eruption as treatment option of crown fracture in maxillary anterior teeth.

Influence of light-curing on the translucence change and color stability of amine-free dual-cured resin cements / 대한치과재료학회지

The aim of this study was to investigate the influence of light-curing on the translucency change and color-stability of amine(tertiary)-free dual-cured resin cements after accelerated aging. Two curing modes (dual-curing and self-curing) were applied on three dual-cured resin cements (Duo-Link Universal [DLU], Nexus Third Generation [NX3] and RelyX Ultimate [RXU]) in this study. Ten specimens were fabricated for each group. In dual-cured groups only, light-activation was performed with polywave-LED curing unit (Bluphase, Ivoclar Vivadent, Schaan, Liechtenstein), where each sides of the samples were photo-polymerized for 60 seconds. Self-cured groups were kept in the dark storage for 24 hours. The color of the specimens was measured with spectrocolorimeter (NF999, Nippon Denshoku, Japan) after 24 hours of making samples. After the initial color measurements, the specimens were subjected to accelerated aging procedure. Spectrophotometric analysis was carried out on day 7, day 14, day 21 and day 28 of accelerated aging in 60 ℃ of distilled water. The color characteristics, color difference (ΔE*), and translucency parameter (TP) of specimens were calculated according to the CIE L*a*b* color system before and after aging. All the ΔE* values and TP values were analyzed by 2-way analysis of variance. After aging, all groups revealed clinically perceptible color differences (ΔE*>3.3). Differences in ΔE* values of self-cured groups were significantly higher than those of dual-cured groups in NX3 and RXU. But there were no significant differences in ΔE* between dual-cured mode and self-cured mode of DLU. All mean b* values increased after aging. All mean L* values decreased after aging except for self-cured RXU cement. TP values also decreased with aging. TP values of self-cured groups were significantly lower than those of dual-cured groups in NX3 and RXU. Hence, in conclusion, despite the absence of tertiary amine in the dual-cured resin cements, such resin cements should be polymerized with the dual-cure modes to ensure long-term color-stability.

Oral manifestation and root canal therapy of the patient with mucopolysaccharidosis

Mucopolysaccharidosis (MPS) is an inherited metabolic disorder caused by a deficiency in enzymes that participate in the degradation of glycosaminoglycans (GAGs) such as heparin sulfate and dermatan sulfate. Left untreated, patients show progressive mental and physical deterioration due to deposition of GAGs in organs. Death often occurs due to cardiac or respiratory failure before patients reach their early twenties. MPS has several oral and dental manifestations. An enlarged head, short neck, and open mouth associated with a large tongue are major characteristics of MPS patients. Dental complications can be severe, including unerupted dentition, dentigerous cyst-like follicles, malocclusions, condylar defects, and gingival hyperplasia. A 21-year-old female patient with MPS was described in this article, with special emphasis on oral manifestations and dental treatment.

Effects of various root canal sealers on tooth discoloration and internal bleaching / 대한치과재료학회지

There are several causes of tooth discoloration following root canal treatment. In this study, we evaluated the effects of sealers on tooth discoloration and internal bleaching. Twenty-four teeth were divided into 4 groups: control group, AH plus, Endosequece BC, and MTA fillapex group. Root canal filling was performed using each sealer conventionally and non-vital bleaching was performed with sodium perborate. The L, a, and b values were measured using Vita easyshade. Tooth discoloration after root canal treatment occurs irrespective of the type of sealers and may cause discoloration with only gutta-percha cone. The effect of non-vital bleaching following the use of calcium silicate-based sealers such as Endosequece BC and MTA fillapex was higher than that of AH plus. Therefore, it needs careful use of sealers in endodontics and calcium silicate-based sealers have advantages of bleaching in case of discolored tooth.

Effects of RetroMTA on osteoblastic differentiation in MC3T3-E1 cells / 대한치과재료학회지

Mineral trioxide aggregate (MTA) provides a very good sealing, acceptable biocompatibility, dentin bridge formation and osteo-inductive effect. However, MTA has a few drawbacks. RetroMTA including calcium-zirconia complex has been developed to overcome drawbacks of MTA, especially long setting time and difficult handling characteristics. Therefore, the aim of this study was to evaluate the effects of RetroMTA on biocompatibility, osteogenic differentiation and mineralization in MC3T3-E1 cells compared with conventional MTA. Cytotoxicity was assessed by WST-1 assay. The gene expression of osteogenic markers was detected by real-time PCR. ALP activity and mineralization behavior were evaluated using ALP and alizarin red staining. There was no statistically significant difference between ProRoot MTA and RetroMTA with material extracts at dilutions of 1/4, 1/10 and 1/50 in cell viability assay. Expression of osteogenic markers in both ProRoot MTA and RetroMTA groups was significantly higher than in control group. In the mineralization assay, RetroMTA showed significantly higher formation of mineralized nodules than in control. In conclusion, RetroMTA promotes osteogenic differentiation and potential mineralization. It appears to be a potential alternative to ProRoot MTA as a root-end filling material.

Dental management of patients with X-linked hypophosphatemia

X-linked hypophosphatemia (XLH) is a hereditary metabolic disease caused by the loss of phosphate through the renal tubules into the urine, and an associated decrease in serum calcium and potassium phosphate. Its dental features include spontaneous dental abscesses that occur in the absence of trauma or dental caries. The aim of this case report was to describe the dental problems of XLH patients and to evaluate limitations in their treatment. A 14 year old male and a 38 year old female with XLH were referred to the Department of Conservative Dentistry for endodontic treatment. The dental findings were periapical abscesses without obvious trauma or caries. Conservative endodontic treatment was performed in teeth with pulp necrosis and abscess. In case 1, the treated teeth showed improvements in bone healing, without clinical symptoms. However, in case 2, the implants and the treated tooth showed hypermobility, and the final restoration was therefore postponed. Early diagnosis, periodic examinations, and communication with the patient's pediatrician are important in the dental management of patients with XLH.

Quantitative Analysis of Tooth Mineral Content by High Resolution Micro-computed Tomography

Teeth and bones are highly mineralized tissues containing inorganic minerals such as calcium phosphate, and a growing number of evidences show that their mineral content is associated with many diseases. Although the quantification of mineral contents by micro-computed tomography(micro- CT) has been used in diagnosis and evaluation for treating bone diseases, its application for teeth diseases has not been well established. In this study, we attempted to estimate a usefulness of a high-resolution micro-CT in analysis of human teeth. The teeth were scanned by using the Skyscan 1172 micro-CT. In order to measure tooth mineral content, beam hardening effect of the machine was corrected with a radiopaque iodinecontaining substance, iodoacetamide. Under the maximum resolution of 6.6 µm, X-ray densities in teeth and hydroxyapatite standards were obtained with Hounsfield unit (HU), and they were then converted to an absolute mineral concentration by a CT Analyzer software. In enamel layer of cusp area, the mean mineral concentration was about 2.14 mg/mm³ and there was a constant mineral concentration gradient from the enamel surface to the dentinoenamel junction. In the dentin of middle 1/3 of tooth, the mean mineral concentration was approximately 1.27 mg/mm³ and there was a constant mineral concentration gradient from the outer of root to the pulp side, ranging from 1.3 to 1.06 mg/mm³. In decay region of dentin, the mineral content was gradually decreased from the intact inner side to the decayed surface. These results suggest that high-resolution micro-CT can be as a useful tool for non-invasive measurement of mineral concentration in teeth.

Evaluation of reparative dentin formation of ProRoot MTA, Biodentine and BioAggregate using micro-CT and immunohistochemistry

OBJECTIVES: The purpose of this study was to assess the ability of two new calcium silicate-based pulp-capping materials (Biodentine and BioAggregate) to induce healing in a rat pulp injury model and to compare them with mineral trioxide aggregate (MTA). MATERIALS AND METHODS: Eighteen rats were anesthetized, cavities were prepared and the pulp was capped with either of ProRoot MTA, Biodentine, or BioAggregate. The specimens were scanned using a high-resolution micro-computed tomography (micro-CT) system and were prepared and evaluated histologically and immunohistochemically using dentin sialoprotein (DSP). RESULTS: On micro-CT analysis, the ProRoot MTA and Biodentine groups showed significantly thicker hard tissue formation (p < 0.05). On H&E staining, ProRoot MTA showed complete dentin bridge formation with normal pulpal histology. In the Biodentine and BioAggregate groups, a thick, homogeneous hard tissue barrier was observed. The ProRoot MTA specimens showed strong immunopositive reaction for DSP. CONCLUSIONS: Our results suggest that calcium silicate-based pulp-capping materials induce favorable effects on reparative processes during vital pulp therapy and that both Biodentine and BioAggregate could be considered as alternatives to ProRoot MTA.

Evaluation of reparative dentin formation of ProRoot MTA, Biodentine and BioAggregate using micro-CT and immunohistochemistry

OBJECTIVES: The purpose of this study was to assess the ability of two new calcium silicate-based pulp-capping materials (Biodentine and BioAggregate) to induce healing in a rat pulp injury model and to compare them with mineral trioxide aggregate (MTA). MATERIALS AND METHODS: Eighteen rats were anesthetized, cavities were prepared and the pulp was capped with either of ProRoot MTA, Biodentine, or BioAggregate. The specimens were scanned using a high-resolution micro-computed tomography (micro-CT) system and were prepared and evaluated histologically and immunohistochemically using dentin sialoprotein (DSP). RESULTS: On micro-CT analysis, the ProRoot MTA and Biodentine groups showed significantly thicker hard tissue formation (p < 0.05). On H&E staining, ProRoot MTA showed complete dentin bridge formation with normal pulpal histology. In the Biodentine and BioAggregate groups, a thick, homogeneous hard tissue barrier was observed. The ProRoot MTA specimens showed strong immunopositive reaction for DSP. CONCLUSIONS: Our results suggest that calcium silicate-based pulp-capping materials induce favorable effects on reparative processes during vital pulp therapy and that both Biodentine and BioAggregate could be considered as alternatives to ProRoot MTA.

A review of the regenerative endodontic treatment procedure

Traditionally, apexification has been used to treat immature permanent teeth that have lost pulp vitality. This technique promotes the formation of an apical barrier to close the open apex so that the filling materials can be confined to the root canal. Because tissue regeneration cannot be achieved with apexification, a new technique called regenerative endodontic treatment was presented recently to treat immature permanent teeth. Regenerative endodontic treatment is a treatment procedure designed to replace damaged pulp tissue with viable tissue which restores the normal function of the pulp-dentin structure. After regenerative endodontic treatment, continued root development and hard tissue deposition on the dentinal wall can occur under ideal circumstances. However, it is difficult to predict the result of regenerative endodontic treatment. Therefore, the purpose of this study was to summarize multiple factors effects on the result of regenerative endodontic treatment in order to achieve more predictable results. In this study, we investigated the features of regenerative endodontic treatment in comparison with those of other pulp treatment procedures and analyzed the factors that have an effect on regenerative endodontic treatment.

Changes in SIRT gene expression during odontoblastic differentiation of human dental pulp cells

OBJECTIVES: The aim of this study was to investigate the expression of 7 different sirtuin genes (SIRT1-SIRT7) in human dental pulp cells (HDPCs), and to determine the role of SIRTs in the odontoblastic differentiation potential of HDPCs. MATERIALS AND METHODS: HDPCs were isolated from freshly extracted third molar teeth of healthy patients and cultulred in odontoblastic differentiation inducing media. Osteocalcin (OCN) and dentin sialophosphoprotein (DSPP) expression was analyzed to evaluate the odontoblastic differentiation of HDPCs by reverse transcription-polymerase chain reaction (RT-PCR), while alizarin red staining was used for the mineralization assay. To investigate the expression of SIRTs during odontoblastic differentiation of HDPCs, real time PCR was also performed with RT-PCR. RESULTS: During the culture of HDPCs in the differentiation inducing media, OCN, and DSPP mRNA expressions were increased. Mineralized nodule formation was also increased in the 14 days culture. All seven SIRT genes were expressed during the odontogenic induction period. SIRT4 expression was increased in a time-dependent manner. CONCLUSIONS: Our study identified the expression of seven different SIRT genes in HDPCs, and revealed that SIRT4 could exert an influence on the odontoblast differentiation process. Further studies are needed to determine the effects of other SIRTs on the odontogenic potential of HDPCs.

Treatment of non-vital immature teeth with amoxicillin-containing triple antibiotic paste resulting in apexification

A recent treatment option for non-vital immature teeth in young patients is revascularization with triple antibiotic paste (TAP). However, tooth discoloration was reported with the use of conventional minocycline-containing TAP. In this case report, amoxicillin-containing TAP was used for revascularization of non-vital immature teeth to prevent tooth discoloration. At the 1 yr follow up, the teeth were asymptomatic on clinical examination and showed slight discoloration of the crown due to mineral trioxide aggregate (MTA) filling rather than amoxicillin-containing TAP. Radiographic examination revealed complete resolution of the periapical radiolucency, and closed apex with obvious periodontal ligament space. However, the root growth was limited, and the treatment outcome was more like apexification rather than revascularization. These results may be due to unstable blood clot formation which could not resist the condensation force of MTA filling, whether or not a collagen matrix was in place. These cases showed that although revascularization was not successful, apexification could be expected, resulting in the resolution of the periapical radiolucency and the closure of the apex. Therefore, it is worthwhile attempting revascularization of non-vital immature teeth in young patients.

Cytotoxicity and physical properties of tricalcium silicate-based endodontic materials

OBJECTIVES: The aim of this study was to evaluate the cytotoxicity, setting time and compressive strength of MTA and two novel tricalcium silicate-based endodontic materials, Bioaggregate (BA) and Biodentine (BD). MATERIALS AND METHODS: Cytotoxicity was evaluated by using a 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-((phenylamino)carbonyl)-2H-tetrazolium hydroxide (XTT) assay. Measurements of 9 heavy metals (arsenic, cadmium, chromium, copper, iron, lead, manganese, nickel, and zinc) were performed by inductively coupled plasma-mass spectrometry (ICP-MS) of leachates obtained by soaking the materials in distilled water. Setting time and compressive strength tests were performed following ISO requirements. RESULTS: BA had comparable cell viability to MTA, whereas the cell viability of BD was significantly lower than that of MTA. The ICP-MS analysis revealed that BD released significantly higher amount of 5 heavy metals (arsenic, copper, iron, manganese, and zinc) than MTA and BA. The setting time of BD was significantly shorter than that of MTA and BA, and the compressive strength of BA was significantly lower than that of MTA and BD. CONCLUSIONS: BA and BD were biocompatible, and they did not show any cytotoxic effects on human periodontal ligament fibroblasts. BA showed comparable cytotoxicity to MTA but inferior physical properties. BD had somewhat higher cytotoxicity but superior physical properties than MTA.

Setting time of MTA

No abstract available.

Autogenous tooth transplantation for replacing a lost tooth: case reports

The autogenous tooth transplantation is an alternative treatment replacing a missing tooth when a suitable donor tooth is available. It is also a successful treatment option to save significant amount of time and cost comparing implants or conventional prosthetics. These cases, which required single tooth extraction due to deep caries and severe periodontal disease, could have good results by transplanting non-functional but sound donor tooth to the extraction site.