• Restorative Dentistry and Endodontics
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• v.30 no.5
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• pp.363-371
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• 2005

This study investigated the effect of thickness of flowable resin lining on marginal leakage in class II composite restorations. 80 experimental teeth were prepared with class II preparations with enamel margin or dentin margin. Each group was devided into four groups according to flowable resin lining thickness ; Control group - no flowable resin lining, Group 1 - 0.5 mm flowable resin lining, Group 2 - 1 mm flowable resin lining, Group 3 - 2 mm flowable resin lining. The cavities were restored using Scotchbond Multi-Purpose adhesive system, Filtek Flow and Filtek Z 250 composite resin. Following one day storage in distilled water, the restored teeth were thermocycled for 500 cycles and immersed in $2\%$ methylene blue for 24 hours. The results of this study were as follows : 1. Ranking of mean microleakage scores at the enamel margins was Group 1 < Control = Group 2 < Group 3. The microleakage of Group 3 was significantly higher than that of Control, Group 1 and Group 2 (p < 0.05). 2. Ranking of mean microleakage scores at the dentin margins was Group 1 < Group 2 < Control < Group 3. The microleakage of Group 3 was significantly higher than that of Control, Group 1 (p < 0.05) 3. Compared with microleakage between the enamel and dentin margins, enamel margin group were significantly lower than dentin margin group.

• Restorative Dentistry and Endodontics
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• v.32 no.4
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• pp.327-334
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• 2007

The purpose of this study was to evaluate the effect of burs on microleakage of Class V resin restorations when a self-etching primer adhesive was used. Forty Class V cavities were prepared with four different cutting burs on extracted third molars, and divided into one of four equal groups (n = 10); Group 1-plain cut carbide bur (no. 245), Group 2-cross cut carbide bur (no. 557), Group 3-fine diamond bur (TF-21F), Group 4-standard diamond bur (EX-41). The occlusal and gingival margin of cavities was located in enamel and dentin, respectively. Cavities were treated with Clearfil SE Bond and restored with Clearfil AP-X. Specimens were thermocycled, immersed in a 2% methylene blue solution for 24 hours, and bisected longitudinally. They were observed leakages at enamel and dentinal margins. Data were analyzed using Mann-Whitney and Wilcoxon signed ranked test. The results of this study were as follows; 1. At enamel margin, microleakage of group 4 was statistically higher than those of group 1, 2 and 3 (p < 0.01). 2. At dentinal margin, microleakage of group 4 was statistically higher than group 3 (p < 0.01), but group 1 and 2 were not statistically different with group 3 and 4. 3. Enamel microleakage was statistically higher than dentinal microleakage in group 1, 2 and 3 (p < 0.05), but statistical difference between the microleakage of enamel and dentinal margin was not in Group 4. In conclusion, the use of coarse diamond bur showed high microleakage at both enamel and dentinal margin when Clearfil SE Bond was used in class V cavity.

• Journal of Periodontal and Implant Science
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• v.33 no.3
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• pp.519-531
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• 2003

The aim of present investigation was to clinically measure the thickness of palatal masticatory mucosa in the hard palate as potential donor site for mucogingival surgery, to determine the relation to shape of palatal vault, form of tooth, gender, and to serve the clinical criteria t o choose the proper surgical technique. 84(mean age:25yrs) systemically and periodontally healthy volunteers participated in this study and 18 standard measurement points were defined in the hard palate, located on 3 lies which ran at different distances parallel to the gingival margin. 6 positions were designated on each of these 3 lines between the level of canine and 2nd molar and a bone sounding technique using a periodontal probe with minimal local anesthesia was utilized to assess the thickness of palatal masticatory mucosa. Student t-test was used to determine the difference in mucosal thickness between 2 groups gender, shape of palatal vault (high palatal vault vs. low palatal vault), tooth form (short-wide vs. long narrow) The result of this study were as follows: 1. Soft tissue thickness progressively increased in sites further away from the gingival margin (p<0.01). 2. Depending on position, in line a and line c the masticatory mucosal thickness increased from Ca to M2(p<0.01), but in line b the thickness increased from Ca to P2, and decreased to M1 and increased again to M2. 3. Gender did not influence the thickness of masticatory mucosa. 4. Palatal vault shape was associated with the thickness of masticatory mucosa. Thickness of low palatal vault group was thicker than high palatal group between P2 and M2 position. 5. Form of tooth did not influence the thickness of masticatory mucosa. In conclusion, palatal vault shape was associated with the thickness of masticatory mucosa. So, mucogingival surgery can be considered as a treatment modality in high palatal vault group. But, Gender and tooth form did not influence the thickness of masticatory mucosa.

• Journal of Periodontal and Implant Science
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• v.49 no.6
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• pp.355-365
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• 2019

Purpose: The modified minimally invasive surgical technique (M-MIST) has been successfully employed to achieve periodontal regeneration. Platelet-rich fibrin (PRF) is known to enhance wound healing through the release of growth factors. This study aimed to observe the outcomes of periodontal surgery when M-MIST was used with or without PRF for the treatment of isolated intrabony defects. Methods: This randomized clinical trial was conducted on 36 systemically healthy patients, who had chronic periodontitis associated with a single-site buccal probing pocket depth (PPD) and clinical attachment level of ≥5 mm. Patients were randomly divided into 2 groups: the test group treated with M-MIST and PRF, and the control group treated with M-MIST alone. The primary periodontal parameters analyzed were PPD, relative attachment level (RAL), and relative gingival margin level. The radiographic parameters analyzed were change in alveolar crest position (C-ACP), linear bone growth (LBG), and percentage bone fill (%BF). Patients were followed up to 6 months post-surgery. Results: Intragroup comparisons at 3 and 6 months showed consistently significant improvements in PPD and RAL in both the groups. In intergroup comparisons, the improvement in PPD reduction, gain in RAL, and the level of the gingival margin was similar in both groups at 3 and 6 months of follow-up. Furthermore, an intergroup comparison of radiographic parameters also demonstrated similar improvements in C-ACP, LBG, and %BF at 6 months of follow-up. Conclusions: M-MIST with or without PRF yielded comparable periodontal tissue healing in terms of improvements in periodontal and radiographic parameters. Further investigation is required to confirm the beneficial effects of PRF with M-MIST.

• Journal of Periodontal and Implant Science
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• v.34 no.3
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• pp.573-580
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• 2004

The Palatal masticatory mucosa was widely used as a donor site in periodontal and implant surgery. but there were relatively few studies investigating the thickness of the palatal mucosa in dentate subjects. The purpose of this study was to study the thickness of palatal masticatory mucosa in korean subjects by direct clinical technique. Forty systemically and periodontally healthy subjects(20 males:20 females) participated in this study. A bone sounding method using a periodontal probe with minimal anesthesia and a prepared clear acrylic stent was utilized to assess the thickness of palatal mucosa at 24 measurement points defined according to the gingival margin and mid palatal suture. The results are as follows; 1. Mean thickness of palatal masticatory mucosa was $3.5{\pm}0.4mm$. and no gender differences were identified in the thickness of palatal masticatory mucosa. 2. The thickness of palatal masticatory mucosa increased from canine to second molar area(with the exception of the first molar area). canine and first molar areas were significantly thinner than other areas(P<0.05). 3. The thickness of palatal masticatory mucosa significantly increased in the sites farther from the gingival margin towarding the mid-palate(P<0.05). The results suggest that within the limits of the present study, premolar area appears to be the most appropriate donor site for soft tissue grafting procedures.

• Journal of the korean academy of Pediatric Dentistry
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• v.29 no.1
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• pp.57-68
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• 2002

The purpose of this study was to evaluate microleakage of etched and non-etched amalgam restorations lined with dentin bonding system primer and adhesives. Class V amalgam preparations were made in 100 extracted human premolars divided into 10 groups with 10 teeth each. SEM was taken to assess the dentin/amalgam interface. The results were as follows; 1. At the occlusal and gingival margins, all experimental groups showed lower leakage value than unlined group(p<0.05) The $Copalite^{(R)}-lined$ group showed higher leakage value than other experimental groups(p<0.05). 2. In all experimental groups, the gingival margin showed higher leakage value than the occlusal margin. 3. There were no significant difference between non-etching and etching groups, primer only and primer & adhesive groups, primer & adhesive and self-priming adhesive groups(p>0.05). 4. On the SEM observation, continuous gaps were observed in the unlined and $Copalite^{(R)}-lined$ groups, but the gaps were filled with primer or adhesive layer in other experimental groups.

• Journal of Periodontal and Implant Science
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• v.45 no.6
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• pp.252-256
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• 2015

Purpose: The purpose of this report was to describe the clinical and microbiological characteristics of two rare cases of necrotizing stomatitis, and the outcomes of a non-invasive treatment protocol applied in both cases. Methods: We report two cases of necrotizing stomatitis in a rare location in the hard palate of a 40-year-old woman and a 28-year-old man. Neither had a relevant medical history and both presented with highly painful ulceration in the palate and gingival margin that was accompanied by suppuration and necrosis. 3% hydrogen peroxide was applied to the lesions using sterile swabs, and antibiotic and anti-inflammatory treatment was prescribed to both patients in addition to two daily oral rinses of 0.2% chlorhexidine. Results: In both cases, radiological examination ruled out bone involvement, and exfoliative cytology revealed a large inflammatory component and the presence of forms compatible with fusobacteria and spirochetes. There was a rapid response to treatment and a major improvement was observed after 48 hours, with almost complete resolution of the ulcerated lesions and detachment of necrotic areas with partial decapitation of gingival papillae. Conclusions: Necrotizing periodontal lesions can hinder periodontal probing and the mechanical removal of plaque in some cases due to the extreme pain suffered by the patients. We present a non-invasive treatment approach that can manage these situations effectively.

• Journal of Periodontal and Implant Science
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• v.30 no.4
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• pp.815-821
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• 2000

The purpose of this study was to evaluate the influence of accessibility to dental cervices of maxillary molars upon plaque control level of these areas. Fifthy-seven dental students with healthy gingiae participated in this study. Maxillary dental casts were fabricated for each participants. Using the casts, cervical accessibility was measured at the mid-palatal point of maxillary first and second molars. Cervical accessibility was defined as the perpendicular distance from the entrance of gingival sulcus to the imaginary line between the most protruded points of palatal gingiva and tooth surface, and classified into degree I(${\leq}0.5mm$), II($>0.5mm,\;{\leq}1.0mm$), III($>1.0mm,\;{\leq}1.5mm$), and IV(>1.5mm). Plaque score was recorded as the distance from crest of gingival margin to the most coronal extent of plaque. Measurements of plaque score were repeated 3 times at 1-week intervals. After the baseline measurements, the participants began to use unitufted brushes on randomly assigned right or left side. Two weeks later, a session of plaque score records identical to the baseline measurements was started. The maxillary second molars showed higher cervical accessibility than the first molars(p<0.01), but the plaque scores of maxillary second molars were also higher than those of first molars(p<0.01). For the maxillary first molars, correlation between accessibility and plaque score was statistically significant, but such correlation was not found for the second molars. Use of unitufted brushes decreased the plaque score(p<0.01). Correlation between accessibility and the degree of plaque score improvement was not found. These findings suggest that cervical accessibility may influence the amount of plaque, and use of adjunctive oral hygiene devices may be helpful in maintaining optimal oral hygiene level at the areas of low cervical accessib ility.

• Restorative Dentistry and Endodontics
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• v.20 no.2
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• pp.732-743
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• 1995

The purpose of this study was to evaluate the adaptation of light cured dentin bonding agents to tooth structure by measuring contraction gaps on interfaces between cavity wall and composite resin under SEM study. In this study, class V cavities with cementum margin were prepared on the buccal surfaces of 15 extracted human premolar teeth and teeth were randomly assigned 3 groups of 5 teeth each. The cavities were filled with three dentin bonding agents and two composite resins were investigated for this study: three dentin bonding agents; Scotchbond 2, Scotchbond Multi-Purpose. All-Bond 2, two composite resins; Silux Pius, Z-100. Group 1 : Scotchbond 2 + Silux Plus Group 2 : Scotchbond Multi~Purpose + Z-100 Group 3 : All-Bond 2 + Z-100 The restored teeth were stored in 100% relative humidity at $37^{\circ}C$ for 7 days. And then, the roots of the teeth were removed with the tapered fissure bur and the remaining crowns were sectioned occlusogingivally through the center of restorations. Adaptation at tooth-restoration interface was assesed occlusally, gingivally, and axially by scanning electron microscope. The results were as follows : 1. In Group 1, the adaptation to dentinal wall of Scotchbond 2 was poor, but the adaptation to enamel wall of Scotchbond 2 was excellent. 2. In Group 2, the adaptation to occlusal was axial wall and gingival wall of Scotchbond Multi-Purpose was excellent. Especially in axially wall, the dentin bonding agents infiltrated into dentinal tubules and there was excellent adaptation to dentinal wall. 3. In Group 3, the adaptation to occlusal wall and axial wall of All-Bond 2 was excellent. But in gingival wall, there was gap formation between composite resin and dentin bonding agent.

• Journal of the korean academy of Pediatric Dentistry
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• v.23 no.2
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• pp.389-400
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• 1996

In Class II amalgam restoration in deciduous molar, failure rate and incidence of recurrent caries are high as children become older. In order to preserve deciduous molars till the physiologic exfoliation time, stainless steel crown is a choice of the treatment. As a result of a careless treatment, such as overhanging margin, poor marginal adaptation, poor proximal contour and inadequate mesiodistal width give rise to interfering eruption of the adjacent teeth, recurrent caries and chronic gingival irritation and insufficient arch length respectively. In this study, 252 s.s. crowned teeth extracted due to physiologic exfoliation or periapical lesion. The purpose of this study is to analyze the marginal adaptation of stainless steel crown to the deciduous molar in order to obtain better clinical result. The results were as follows : 1. Between the length of s.s. crown and the marginal gap of crown, positive correlations were shown. 2. Largest amount of marginal gap was shown at buccal side in upper deciduous molars and lower first deciduous molar, lingual side in lower second deciduous molar. But no significant diffrence were found statistically compared to second most largest one. 3. Incidence of exposed restoration and recurrent caries were higher in proximal surface than buccal/lingual surface. And extension of restoration below the margin of s.s. crown gives rise to higher rate of recurrent caries. 4. Defect of contour was found in 34%, frequently found in lower 1st deciduous molar and upper 1st deciduous molar. 5. Marginal polishing defects were found in 23%. 6. Ledge was formed in 10% especially in lower 1st deciduous molar and lower 2nd deciduous molar. 7. 16% of the teeth had wear facet due to traumatic occlusion, 7% of them had occlusal perforation.