• Journal of the korean academy of Pediatric Dentistry
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• v.25 no.4
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• pp.749-760
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• 1998

The main purpose of this study was to evaluate the effect of dentin with various pretreatment application time on the dentin surface structure and the bond strength of glass ionomer restorative matrials between primary and permanent tooth. There are difference of composition, structure and pretreated effect of dentin conditioning between the primary and permanent teeth. Inspite of thease fact, we used the same application time of permanent tooth. This study intends to determine the most effective application time using SEM analysis of the surface change by dentin conditioning. Forty five intact primary and permanent teeth were splited mesiodistally with seperating diamond disk. Each eight specimens were prepared for shear bond strength test. (randomely devided eight group as follows:) group I conditioning for five seconds group II conditioning for ten seconds group III conditioning for fifteen seconds group IV conditioning for twenty seconds Additional specimens were prepared to SEM analysis. The result are as follows: 1. Primary teeth are higher shear bond strength in group I and group II. 2. There was no statistically significant difference between primary and permanent teeth in group III and group IV. 3. In SEM analysis, smear layer removal by dentin pretreatment of primary teeth was faster than permanent teeth. Primary teeth may require shorter pretreatment time of dentin for G-I restoration than that of permanent teeth.

• Journal of Periodontal and Implant Science
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• v.29 no.4
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• pp.861-872
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• 1999

Since pathologic changes of exposed root surface inhibit cell attachment and new attachment of connective tissue have been made, many efforts were apply to change the exposed root surface condition. Scaling and root planing can not remove the endotoxin completely and forms the smear layer which prohibits the new attachment of connective tissue. Therefore, many kinds of chemicals were used for controlling the pathologic change of the root surface. The purposes of this study was to compare and observe the changes of the exposed root surface treated by scaling and root planning, Tetracycline HCl and Argon Laser. After the scaling and root planning of ten extracted premolars, the differences & the root surface among groups were observed under SEM. Control group showed smear layer and irregular amorphous surface. The dentinal tubule was not exposed. The debris and scale like texture were also observed. Tetracycline HCl treated group showed relatively smooth surface and the collagen fiber was observed in the dentinal tubule. Argon Laser treated group showed the most effective results under the conditions of 0.8 to 1.0w irradiation for 0.5 to 1.0 sec with pulse wave. The results of this study showed that the root surface change was associated with the intensity and the duration of Argon Laser irradiation. Further investigation for the surface change with the Argon Laser irradiation is recommended for understanding of clinical effect.

• Journal of Periodontal and Implant Science
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• v.29 no.4
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• pp.847-863
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• 1999

The present study was performed to evaluate the effect of EDTA on diseased root surfaces with regard to the removal of the smear layer, exposure of dentinal tubule openings, and demineralization of the peritubular dentin. 20 periodontally involved single rooted teeth were used. After scaling and root planing, root conditioning was carried out with 3%, 17%, and 24% EDTA solution for 20 sec., 3 min., and 5 min. respectively. Then, the specimens were rinsed with tap water for 5 min. and processed for scanning electron microscopic observation. The following results were obtained. 1. In control group which was conditioned with cotton pellets soaked with saline for 3 min., the surface showed an amorphous irregular coating. The tubule orifices seemed to be com-pressed in the direction of the curette strokes. 2. In test group which was conditioned with EDTA solution, the number of opening dentinal tubules and the extent of the dentinal tubule opening increased with time irrespective of the concentration of EDTA solution. 3. In the group which was conditioned with EDTA solution for 20 sec., the smear layer was not completely removed. 4. If the time of root conditioning is above 3 min., collagen-like fibers covering the circum tubular dentin surface were shown even in the group which was conditioned with 3% EDTA solution. In conclusion, EDTA solution was a very effective root conditioning agent like low pH root conditioning agents which had various disadvantages. Therefore, using EDTA solution, more successful periodontal regeneration could be obtained.

• Journal of Periodontal and Implant Science
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• v.23 no.3
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• pp.564-576
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• 1993

The purpose of this study was to evaluate the effects of Nd:YAG laser treatment on removal of smear layer and exposure of dentinal tubules. The experimental specimens were obtained from root planed surface of 30 human teeth which were extracted due to severe periodontal disease. The specimens were assigned randomly of three groups: root planed group, Tetracycline HCl(100mg/ml, 5min) group, and Nd:YAG laser ($Laser-35^{TM}$, U.S.A. 5 seconds )group. Nd:YAG laser group was divided into 4 subgroups according to 3.0W, 3.5W, 4.0W, 4.5W of power. The surface change of specimens were evaluated by scanning electron microscopy. The number of exposed dentinal tubules and percentage of area occupied by dentinal tubule orifices per unit area between each group was statistically analyzed by paired Student t-test. The results were as follows: 1. By root planing only, dentinal tubule was not exposed, but scale-like smear layer and parallel instrument tracks were resulted. 2. Tetracycline HCl treated surfaces exhibited the small number of partially exposed dentinal tubules with long orifices. The number($3.80{\pm}0.79$) of exposed dentinal tubules on Tetracycline HCl group was significantly less than that in laser groups above 3.5W of power(P<0.001), and the percentage ($0.68{\pm}0.19$) of area occufied by dentinal tubule orifices per unit area($192\;{\mu}m^2$) was significantly lower than that of any laser group(P<0.001). 3. The laser group irradiated with 4.5W of power showed both the most number($10.60{\pm}0.97$) of exposed dentinal tubules among the experimental groups, and the highest percentage($3.75{\pm}0.55\;%$) of area occupied by dentinal tubule orifices. 4. Energy Surge during laser pulsing and overlapping passes of the fiber resulted in melted and resolidified surface textures with lava-like appearance.

• Restorative Dentistry and Endodontics
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• v.43 no.2
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• pp.14.1-14.16
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• 2018

Objectives: The aim of this systematic review was to critically analyze previously published studies of the effects of dentin surface pretreatment with deproteinizing agents on the bonding of self-etch (SE) adhesives to dentin. Additionally, a meta-analysis was conducted to quantify the effects of the above-mentioned surface pretreatment methods on the bonding of SE adhesives to dentin. Materials and Methods: An electronic search was performed using the following databases: Scopus, PubMed and ScienceDirect. The online search was performed using the following keywords: 'dentin' or 'hypochlorous acid' or 'sodium hypochlorite' and 'self-etch adhesive.' The following categories were excluded during the assessment process: non-English articles, randomized clinical trials, case reports, animal studies, and review articles. The reviewed studies were subjected to meta-analysis to quantify the effect of the application time and concentration of sodium hypochlorite (NaOCl) and hypochlorous acid (HOCl) deproteinizing agents on bonding to dentin. Results: Only 9 laboratory studies fit the inclusion criteria of this systematic review. The results of the meta-analysis revealed that the pooled average microtensile bond strength values to dentin pre-treated with deproteinizing agents (15.71 MPa) was significantly lower than those of the non-treated control group (20.94 MPa). Conclusions: In light of the currently available scientific evidence, dentin surface pretreatment with deproteinizing agents does not enhance the bonding of SE adhesives to dentin. The HOCl deproteinizing agent exhibited minimal adverse effects on bonding to dentin in comparison with NaOCl solutions.

• Restorative Dentistry and Endodontics
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• v.23 no.1
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• pp.515-524
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• 1998

The purposes of this study were to observe the cavity wall morphology and to evaluate the degree of cavity cleanliness when root-end retrograde cavity preparation was done with ultrasonic diamond instruments. To observe the morphology of retrocavity and to evaluate the degree of cavity cleanliness. root-end resections were done on 20 palatal roots of extracted maxillary first molars after canal filling with gutta-percha. Retrocavities were prepared using either ultrasonic diamond instruments or stainless steel ones of medium power setting of level 6 ($Miniendo^{TM}$, EIE, CA, U.S.A.). Morphology of the cavity. degrees of the remaining canal debris and smear layer were evaluated under the scanning electron microscope. The results were as follows: Cavities prepared with ultrasonic diamond instruments showed scratched appearance of wall, while ultrasonic stainless steel preparation showed hatcheted appearance. Ultrasonic diamond instruments induced more smear layer than stainless steel ones did (p<0.01) in the cavity. However, there was no significant difference in canal debris (p>0.05).

• Journal of Periodontal and Implant Science
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• v.52 no.1
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• pp.54-64
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• 2022

Purpose: This in vitro study was conducted to evaluate the effects of different debridement techniques and conditioning procedures on root surface morphology and blood clot stabilization. Methods: Two debridement techniques (curette [CU] vs. high-speed ultrasound [US]) and 2 conditioning procedures (ethylenediaminetetraacetic acid [EDTA] and phosphoric acid [PA]) were used for the study. Seven experimental groups were tested on root surfaces: 1) no treatment (C); 2) CU; 3) US; 4) CU+EDTA; 5) US+EDTA; 6) CU+PA; and 7) US+PA. Three specimens per group were observed under scanning electron microscopy (SEM) for surface characterization. Additional root slices received a blood drop, and clot formation was graded according to the blood element adhesion index by a single operator. Data were statistically analyzed, using a threshold of P<0.05 for statistical significance. Results: The C group displayed the most irregular surface among the tested groups with the complete absence of blood traces. The highest frequency of blood component adhesion was shown in the CU+EDTA group (P<0.05), while no differences were detected between the CU, US+EDTA, and CU+PA groups (P<0.05), which performed better than the US and US+PA groups (P<0.05). Conclusions: In this SEM analysis, EDTA and conventional manual scaling were the most efficient procedures for enhancing smear layer removal, collagen fiber exposure, and clot stabilization on the root surface. This technique is imperative in periodontal healing and regenerative procedures.

• Restorative Dentistry and Endodontics
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• v.48 no.3
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• pp.28.1-28.13
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• 2023

Objectives: This study aimed to investigate the effect of the application method of 2% chlorhexidine (CHX) and its influence on the adhesion of fiberglass posts cemented with a self-adhesive resin cement. Materials and Methods: Sixty human mandibular premolars were endodontically treated and divided into 5 groups (n = 12), according to the canal irrigant and its application method: 2 groups with conventional syringe irrigation (CSI)-2.5% sodium hypochlorite (NaOCl) (control) and 2% CHX- and 3 groups with 2% CHX irrigation/activation-by passive ultrasonic irrigation (PUI), Easy Clean file, and XP-Endo Finisher file. Two roots per group were evaluated for smear layer (SL) removal by scanning electron microscopy. For other roots, fiber posts were luted using a self-adhesive resin cement. The roots were sectioned into 6 slices for push-out bond strength (BS) (7/group) and nanoleakage (NL) (3/group). Data from SL removal were submitted to Kruskal-Wallis and Student-Newman-Keuls tests (α = 0.05). Data from BS and NL were evaluated by 2-way analysis of variance and Tukey's test (α = 0.05). Results: For SL removal and BS, the CHX irrigation/activation promoted better values than CSI with CHX (p < 0.05), but it was not significantly different from CSI with NaOCl (p > 0.05). For NL, the lowest values were obtained by the chlorhexidine irrigation/activation groups (p < 0.05). Conclusions: Active 2% CHX irrigation can be used to improve the post space cleaning and adhesion before fiber post cementation with self-adhesive resin cements.

• Restorative Dentistry and Endodontics
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• v.24 no.3
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• pp.465-472
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• 1999

The aim of this study was to determine the shear bond properties of four dentin bonding systems to internal cervical dentin, and to investigate the effect of the pretreatment for removing smear layer and position of dentin on shear bond strength of dentin bonding agents. The materials tested in this study were consisted of four commercially available dentin bonding systems[Allbond 2(AB), Clearfil Linerbond 2(CL), Optibond FL(OP), Scotchbond Multi-purpose(SB)], a restorative light-cured composite resin[Z100]J and a chelating agent[RC-prep(RC)]. Fifty-six freshly extracted human molars were used in this study. Dentin specimens were prepared by first cutting the root of the tooth 1mm below the cementoenamel junction with a diamond bur in a high speed handpiece under air-water coolant, and then removing occlusal part at pulp horn level by means of a second parallel section, The root canal areas were exposed by means of cutting the dent in specimens perpendicular to the root axis. Dentin specimens were randomly assigned to two groups(pretreated group, not-pretreated group) based on the pretreatment method of dentin surface. In pretreated group, RC was applied to dentin surface for 1minute and then rinsed with NaOCl. In not-pretreated group, dentin surface was rinsed with saline Each groups were subdevided into four groups according to dentin bonding systems. Four dentin bonding systems and a restorative resin were applied according to the directions of manufacturer. The dentin-resin specimens were embedded in a cold cure acrylic resin, and were cut with a low speed diamond saw to the dimension of $1{\times}1mm$. The cut specimens were divided into three groups according to the position of internal cervical dentin. The shear bond properties of dentin-resin specimens were measured with Universal testing machine (Zwick, 020, Germany) with the cross head speed of 0.5mm/min. From this experiment. the following results were obtained : 1. In case of shear bond strength, there was no significant difference among dentin bonding systems in not-pretreated groups, whereas in pretreated groups, the shear bond strengths of AB and of SB were statistically significantly higher than those of CL and of OP. 2. The shear bond strengths of AB and of SB in pretreated groups were significantly higher than those in not-pretreated groups. 3. The shear bond strengths of radicular layer of OP were higher than those of occlusal layer of OP in not-pretreated groups, and of AB in pretreated groups. The shear bond strengths of radicular layer of AB and of CL in not-pretreated groups were higher than those in pretreated group.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.2
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• pp.272-285
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• 2003

This study was conducted to observe the microscopic structures of cavities formed after ablation of primary teeth, permanent teeth, enamel and dentin in using a bur and cavities formed after ablation using laser and the following results were obtained after comparing the effects of ablation. Using a #330 bur and Er:YAG laser irradiated at 150 mJ, 200 mJ, 250 mJ and 300 mJ all at the frequency of 5 Hz, 1 mm enamel and dentin samples were ablated and the ablation time was measured. In order to measure the surfaces ablated, 5 each of primary teeth and permanent teeth were ablated using a #330 bur and Er:YAG laser at 150 mJ, 200 mJ, 250 mJ and 300 mJ for 1 sec and the cross section and vertical section were observed. The following results were obtained : 1. Cutting time of Er:YAG laser was longer than that of conventinal high-speed bur regardless of teeth type. 2. Cutting on enamel, Cutting time of conventional high-speed bur in deciduous teeth was longer than in permanent teeth(P<0.05). But Er:YAG laser was not showed any difference between the deciduous and permanent teeth(P>0.05). 3. Cutting on dentin, Cutting time of conventional high-speed bur in permanent teeth was longer than deciduous teeth. Er:YAG laser of 150 mJ, 5 Hz in permanent teeth was longer than in deciduous teeth(p<0.05). But laser of other power did not showed mean difference. 4. The cavity surface treated with the convetional high-speed bur revealed a relatively flat appearance, almost covered with a debris-like smear layer. Cavity wall showed striped appearance because of blade of bur. 5. The cavity surface treated by the Er:YAG laser system was irregular or rough surface with the absence charring, carbonization, or cracking of the dentin. In addition, there was an absence of a smear layer. Cavity floor was round and relatively smooth. According to these results, cutting time of Er:YAG laser was almostly same in permanent and deciduous teeth, but more effective in dentin than enamel. Cutting the sample, Er:YAG laser was needed more time than conventional bur. But SEM findings suggested that laser device produced favorable surface characteristic(i.e, no smear layer, irregular surface, cracking).