• Journal of the korean academy of Pediatric Dentistry
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• v.39 no.1
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• pp.84-89
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• 2012

The radicular cyst is the most common odontogenic cyst which is caused by pulpal inflammation, pulp death, and secondary to trauma or dental caries. Usually, the radicular cyst is asymptomatic, but a secondary inflammation can cause pain, swelling and redness. Getting larger, the radicular cyst can cause facial asymmetry and paresthesia by pressure on nerves. It requires conservative endodontic treatment or surgical approach. When the size of cyst is large or invasion of the adjacent tissue is not expected, cyst enucleation is carried out. And most of the case can be completely cured and shows low recurrence. In these radicular cysts cases, by cyst enucleation or apicoectomy after root canal treatment simultaneously, the infected teeth can be preserved successfully.

• Restorative Dentistry and Endodontics
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• v.38 no.4
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• pp.258-262
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• 2013

The restorative management of deep carious lesions and the preservation of pulp vitality of immature teeth present real challenges for dental practitioners. New tricalcium silicate cements are of interest in the treatment of such cases. This case describes the immediate management and the follow-up of an extensive carious lesion on an immature second right mandibular premolar. Following anesthesia and rubber dam isolation, the carious lesion was removed and a partial pulpotomy was performed. After obtaining hemostasis, the exposed pulp was covered with a tricalcium silicate cement (Biodentine, Septodont) and a glass ionomer cement (Fuji IX extra, GC Corp.) restoration was placed over the tricalcium silicate cement. A review appointment was arranged after seven days, where the tooth was asymptomatic with the patient reporting no pain during the intervening period. At both 3 and 6 mon follow up, it was noted that the tooth was vital, with normal responses to thermal tests. Radiographic examination of the tooth indicated dentin-bridge formation in the pulp chamber and the continuous root formation. This case report demonstrates a fast tissue response both at the pulpal and root dentin level. The use of tricalcium silicate cement should be considered as a conservative intervention in the treatment of symptomatic immature teeth.

• Journal of Dental Anesthesia and Pain Medicine
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• v.15 no.2
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• pp.69-76
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• 2015

Background: There have been few studies on the effect of an elevated concentration of lidocaine hydrochloride in the surgical removal of an impacted lower third molar. This study aimed to examine the efficacy of 4% lidocaine along with 1:100,000 epinephrine compared to 2% lidocaine along with 1:100,000 epinephrine as inferior alveolar nerve block for the removal of an impacted lower third molar. Methods: This single-blind study involved 31 healthy patients (mean age: 23 y; range: 19-33 y) with symmetrically impacted lower third molars as observed on panoramic radiographs. Volunteers required 2 surgical interventions by the same surgeon with a 3-week washout period. The volunteers were assigned either 4% lidocaine with 1:100,000 epinephrine or 2% lidocaine with 1:100,000 epinephrine as local anesthetic during each operation. Results: We recorded the time of administration, need for additional anesthetic administration, total volume of anesthetic used. We found that the patient's preference for either of the 2 types of local anesthetic were significantly different (P < 0.05). However, the extent of pulpal anesthesia, surgical duration, and duration of soft tissue anesthesia were not significantly different. Conclusions: Our study suggested that inferior alveolar nerve block using 4% lidocaine HCl with 1:100,000 epinephrine as a local anesthetic was clinically more effective than that using 2% lidocaine HCl with 1:100,000 epinephrine; the surgical duration was not affected, and no clinically adverse effects were encountered.

• Journal of Oral Medicine and Pain
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• v.30 no.3
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• pp.375-381
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• 2005

Er:YAG laser has been considered a promising alternative to dental drill and many researches indicate that adjustment to variable parameters, including water flow rate, pulse energy and pulse repetition rate, can be made to improve ablation ability and efficiency of the laser. Of these parameters, addition of water spray during irradiation has been thought to ablate dental hard tissue more rapidly and safely. The purpose of this study was to investigate tooth ablation amount by Er:YAG laser irradiation as related to varied water flow rates added and, ultimately to find the most effective water flow rate for ablation. In addition, the temperature change of pulp chamber during irradiation was also monitored on the irradiated and opposite pulpal walls, respectively. An Er:YAG laser with contact mode was employed. Extracted human molars were split into two pieces for ablation experiment. Pulse energies of 200 and 300 mJ with a pulse repetition rate of 20 Hz and 5 water flow rates (1.6, 3.0, 5.0, 7.0, and 10.0 ml/min) were applied. Each irradiation was performed for 3 seconds. According to these parameters, experimental groups were divided into 10 subgroups which consisted of 5 specimens. For temperature experiment, another 5 tooth-specimens were prepared in the manner that pulp chamber was open through access cavity preparation and two temperature-measuring probes were placed respectively on the irradiated and the opposite walls of pulp chamber. From the experiment on ablation amount related to different water flow rates, it was shown that the least water flow rate of 1.6 ml/min ablated more than any other water flow rates (p<0.000). When the irradiation for 3 seconds, combined with the pulse repetition time of 20Hz and the water flow rate of 1.6 ml/min was done to tooth specimen, the temperature rise was not noticeable both on the irradiated and the opposite pulpal walls (less than 3$^{\circ}C$) and there was no significant difference in temperature rise between the two pulse energies, 200 and 300 mJ. From the results of this study, it is suggested that tooth ablation with Er:YAG laser can be done effectively and safely at a energy between 200 and 300 mJ/pulse and a pulse repetition rate of 20 Hz when the lasing is conjugated with the water flow rate of 1.6ml/min.

• Journal of Periodontal and Implant Science
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• v.29 no.1
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• pp.51-63
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• 1999

Exposure of the root surface due to gingival recession after periodontal surgery, elicit pain response when exposed to mechanical, heat, chemical or osmotic irritation. Especially patients treated with periodontal surgery, show high frequency. There have been reports that the 1 out of 7 patients complains of dentinal hypersensitivity. There have been many studies on the clinical effects of various materials on the treatment of dentinal hypersensitivity. The purposes of this study were to evaluate the effect of sodium chloride and potassium oxalate and to observe the relationship between the dentinal hypersensitivity and surface characteristics such as dentinal tubule size and number. This study included 20 teeth which were scheduled for extraction and had no pulpal disease. These teeth were divided into Root planing group, EDTA group, NaCl group and Oxalate group. Dentinal hypersensitivity is measured by tactile, pressured air and cold water using NRS (Numerical Rating Scales). Teeth were extracted under local anesthesia and each specimen was sectioned to a size about 3 X 5 mm and was examined under the scanning electron microscope (X2,000) The results were as follows, 1. The EDTA group exhibited significantly increased dentinal hypersensitivity comparing with the other groups. 2. The NaCl and Oxalate groups showed significantly reduced dentinal hypersensitivity comparing with the EDTA group. 3. As a method for dentinal hypersensitivity measurement, it was presumed thet tactile sensitivity test was not sensitive method but air blast test and cold water test were adequate method. 4. In a SEM study, the root planing group exhibited amorphous smear layer and showed no dentinal tubule orifice, but the EDTA group showed the large number of dentinal tubules. On the other hand, the NaCl and Oxalate groups did not show exposed dentinal tubules. The NaCl group showed more rough root surface than the EDTA group, and the Oxalate group showed many participates to be presumed as calcium oxalate particle. As the results from this study, root planing couldn't expose the dentinal tubule and NaCl and potassium oxalate occluded exposed dentinal tubule effectively. Dentinal hypersensitivity has close relationship with the exposure of dentinal tubules, especially with it's size and number.

• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.4
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• pp.558-563
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• 2000

The lasers have been used in dentistry for more than 30 years and the application of lasers for drilling dental hard tissue has been investigated since the early developement of lasers. Recently, the Er:YAG laser was invented for hard tissue ablation. The Er:YAG laser, having a wavelength of 2.94um, is highly absorbed in both water and hydroxiapatite, leading to a very effective material for hard tissue removal by bursting off the solid tissue component that is, enamel and dentin are removed by the Er :YAG laser by water vaporization and microexplosion, without any melting of inorganic tissues. Therefore, the Er:YAG laser produced round craters with well defined margins and the surrounding tissues had no cracks and no charring. When used for cavity preparation, pulpal damage should not occur if hear buildup is minimized by careful selection of exposure parameters and by use of a water spray. The present study demonstrated that the Er:YAG laser cut the tooth substance adequately for composite resin restoration, without having undesirable side effects such as harmful effects on the pulp, discoloration or cracking etc. Also, the child patients were well cooperative during laser treatment mainly because of little noise, lesser vibration and minimal pain compared to conventional means of cavity preparation.

• Journal of Oral Medicine and Pain
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• v.30 no.4
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• pp.457-464
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• 2005

The purpose of our study was to investigate whether the intrapulpal temperature during cavity preparation of enamel or dentin with Er:YAG laser still remained in range of safety for dental pulp protection when combined with appropriate water flow rate. The effect of different pulse repetition rates at the same pulse energy during ablation was evaluated as well. Caries-free, restoration-free extracted human molar teeth were prepared for the specimen and divided two experimental groups of enamel and dentin. Each group comprised 5 specimens and each of tooth specimens were embedded into a resin block each and measuring probe was placed on the irradiated pulpal walls. For experiments of dentin ablation, enamel layers were prepared to produce dentin specimen with a same dentin thickness of 2 mm. A pulse energy of Er:YAG laser was set to 300 mJ and three different pulse repetition rates of 20 Hz, 15 Hz and 10 Hz were employed. Laser beam was delivered with 3 seconds and less per application over enamel and dentin surfaces constant sized by $3\;mm{\times}2\;mm$ and water spray added during irradiation was a rate of 1.6 ml/min. Temperature change induced by Er:YAG laser irradiation was monitored and recorded While enamel was ablated, there was no significant difference of temperature related to pulse repetition rates(p=0.358) and temperature change at any pulse repetition rate was negligible. Significant statistical difference in temperature changes during cavity preparation in dentin existed among three different pulse groups(p=0.001). While temperature rise was noticeable when the dentinal wall was perforated, actual change of temperature due to Er:YAG laser irradiation was not enough to compromise safety of dental pulp when irradiation was conjugated with appropriate water spray. Conclusively, it can be said that cavity preparation on enamel or dentin with an Er:YAG laser is performed safely without pulp damage if appropriate volume of water is sprayed properly over the irradiated site.

• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.2
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• pp.219-227
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• 2001

Little is known about processing mechanism of pain sensation of the oral cavity at the 1st synapse of trigeminal sensory nuclei. Serial ultrathin sections of tooth pulp afferent terminals, identified by the transganglionic transport of 1% wheatgerm agglutinin conjugated horseradish peroxidase, were investigated with electron microscope. Quantitative ultrastructural analysis was performed on digitizing tablet connected to Macintoshi personal computer (software; NIH Image 1.60, NIH, Bethesda, MD). Labeled boutons could be classified into two types by the shapes of containing vesicles : S bouton, which contained mainly spherical vesicles (Dia. 45-55 nm) and few large dense cored vesicles (Dia, 80-120nm), and LDCV bouton, which contained spherical vesicles as well as large number of large dense cored vesicles. Most of the parameters on the ultrastructural characteristic and synaptic organization of labeled boutons were similar between S and LDCV boutons, except shapes of containing vesicles. Majority of the labeled boutons showed simple synaptic arrangement. The labeled boutons were frequency presynaptic to dendritic spine, and to a lesser extent, dendritic shaft. They rarely synapsed with soma and adjacent proximal dendrite. A small proportion of labeled boutons made synaptic contacts with presynaptic, pleomorphic vesicles containing endings and synaptic triad. Morphometric parameters of labeled boutons including volume and surface area, total apposed area, mitochondrial volume, active zone area, vesicle number and density showed wide variation and these were not significantly different between S and LDCV boutons. The present study revealed characteristic features on ultrastructure and synaptic connection of pulpal afferents which may involved in transmission of oral pain sensation.

• Journal of Oral Medicine and Pain
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• v.31 no.3
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• pp.223-229
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• 2006

The objectives of this study was to investigate the amount of tooth ablation and the change of intrapulpal temperature by Er:YAG laser as it relates to pulse energy and pulse repetition rate at the identical power and, thereby, to reveal which of the two parameters strongly relates with ablation efficiency and intrapulpal temperature. Extracted healthy human molar teeth were sectioned into two pieces and each specimen was irradiated within the combination of pulse energy and pulse repetition time at the same power of 3W; $300mJy{\times}10Hz$ group, $200mJy{\times}15Hz$ group, and $150mJy{\times}20Hz$ group. Each specimen comprised ten tooth specimens. A laser beam with conjunction of a water flow rate of 1.6 ml/min was applied over enamel surfaces of the specimens during 3 seconds and the ablation amount was determined by difference in weight before and after irradiation. To investigate the temperature change in the pulp according to the above groups, another five extracted healthy human molar teeth were prepared. Each tooth was embedded into resin block and the temperature-measuring probes were kept on the irradiated and the opposite walls in the dental pulp during lasing. When the power was kept constant at 3W, ablation amount increased with pulse energy rather than pulse repetition rate (p=0.000). Although intrapulpal temperature increased with pulse repetition rate, there were no significant differences among the groups and between the irradiated and the opposite pulpal walls, except at a condition of $150y{\times}20Hz$ (p=0.033). Conclusively, it is suggested that ablation efficacy is influenced by pulse energy rather than pulse repetition rate.