Esthetic improvements through systematic diagnosis and treatment procedures in patients with unesthetic maxillary anterior teeth proportion after orthodontic treatment: Case report / 대한치과보철학회지

The treatment of areas demanding esthetic requirements, such as maxillary anterior teeth, should take into account the achievement of a healthy, harmonious to the surrounding tissue, and an attractive smile line. In this case report, smile line, soft tissue and hard tissue morphology, and the anatomy and proportion of the tooth, must be considered. In patients with unesthetic maxillary anterior ratio due to inadequate gingival contour and diastema caused by peg lateralis, it would be challenging to achieve an esthetic restoration by orthodontic treatment alone. In such case, after orthodontic treatment, dento-gingivo-facial compositional diagnosis and analysis, followed by gingivectomy and prosthodontic restoration is needed to improve the interdental mesial/distal, width/length ratio to achieve a satisfactory esthetic result. In addition, when improving the tooth proportion of peg lateralis by prosthodontic treatment, Porcelain laminate veneer (PLV), which results in less tooth structure loss, reproduction of similar shade to that of the proximal tooth and high transparency, is recommended. This case report demonstrates esthetic improvements by prosthodontic restoration through systematic diagnosis and treatment procedure in patients with unesthetic maxillary anterior proportion after orthodontic treatment due to peg lateralis by means of two female patients aged twenty years old.

In vitro evaluation of the fracture resistance and microleakage of porcelain laminate veneers bonded to teeth with composite fillings after cyclic loading

PURPOSE: There is insufficient data regarding the durability of porcelain laminate veneers bonded to existing composite fillings. The aim of the present study was to evaluate the fracture resistance and microleakage of porcelain laminate veneers bonded to teeth with existing composite fillings. MATERIALS AND METHODS: Thirty maxillary central incisors were divided into three groups (for each group, n=10): intact teeth (NP), teeth with class III composite fillings (C3) and teeth with class IV cavities (C4). Porcelain laminate veneers were made using IPS-Empress ceramic and bonded with Panavia F2 resin cement. The microleakage of all of the specimens was tested before and after cyclic loading (1 x 10(6) cycles, 1.2 Hz). The fracture resistance values (N) were measured using a universal testing machine, and the mode of failure was also examined. The statistical analyses were performed using one-way ANOVA and Tukey post hoc tests (alpha=0.05). RESULTS: There was a significant difference in the mean microleakage of group C4 compared with group NT (P=.013). There was no significant difference in the fracture loads among the groups. CONCLUSION: The microleakage and failure loads of porcelain laminate veneers bonded to intact teeth and teeth with standard class III composite fillings were not significantly different.

A study on enamel thickness of maxillary incisors using X-ray micro computed tomography / 대한치과보철학회지

PURPOSE: The objectives of the current study are to assess the accuracy of X-Ray Micro Computed Tomography (microCT) in measuring enamel thickness and to evaluate enamel thickness in maxillary incisors of Koreans. MATERIAL AND METHODS: Five maxillary incisors were embedded in resin block. These teeth were longitudinally sectioned labiolingually through the medial axis. After polishing, the teeth were scanned using a microCT (X-EYE SYSTEM; DRGEM, Seoul, Korea). On a scanning electron microscope (S-4300; Hitachi, Tokyo, Japan) (x20) and a microCT, nearly identical planes were reconstructed. In each tooth, the thickness of labial enamel was measured 1, 3 and 5 mm above the cementoenamel junction (CEJ). Thus, the accuracy of the microCT was evaluated. In addition, using 26 maxillary central incisors and 11 maxillary lateral incisors, in the medial axis and 2 mm remote areas mesially and distally from the medial axis, the thickness of labial enamel was measured 1, 3 and 5 mm above the CEJ along the long axis of the teeth RESULTS: Measurements from nearly identical planes in physical and microCT sections differed by 3.81%. An independent t-test was performed and this showed that there were no significant differences in the measurements between the two methods. Mean values of labial enamel thickness in maxillary central incisors 1, 3 and 5 mm above the CEJ were 0.32 +/- 0.01, 0.50 +/- 0.02 and 0.70 +/- 0.02 mm, respectively. Mean values of labial enamel thickness in maxillary lateral incisors 1, 3 and 5 mm above the CEJ were 0.30 +/- 0.01, 0.55 +/- 0.03 and 0.80 +/- 0.02 mm, respectively. CONCLUSION: In measuring enamel thickness, microCT is one of useful way of measurement. So according to the results of this research, when restoring a porcelain laminate veneer on maxillary incisors in Koreans, careful consideration is needed in the amount of enamel reduction.

The effect of the amount of interdental spacing on the stress distribution in maxillary central incisors restored with porcelain laminate veneer and composite resin: A 3D-finite element analysis / 대한치과보존학회지

This study evaluated the influence of the type of restoration and the amount of interdental spacing on the stress distribution in maxillary central incisors restored by means of porcelain laminate veneers and direct composite resin restorations. Three-dimensional finite element models were fabricated to represent different types of restorations. Four clinical situations were considered. Type I, closing diastema using composite resin. Labial border of composite resin was extended just enough to cover the interdental space; Type II, closing diastema using composite resin without reduction of labial surface. Labial border of composite resin was extended distally to cover the half of the total labial surface; Type III, closing diastema using composite resin with reduction of labial surface. Labial border of the preparation and restored composite resin was extended distally two-thirds of the total labial surface; Type IV, closing diastema using porcelain laminate veneer with a feathered-edge preparation technique. Four different interdental spaces (1.0, 2.0, 3.0, 4.0 mm) were applied for each type of restorations. For all types of restoration, adding the width of free extension of the porcelain laminate veneer and composite resin increased the stress occurred at the bonding layer. The maximum stress values observed at the bonding layer of Type IV were higher than that of Type I, II and III. However, the increasing rate of maximum stress value of Type IV was lower than that of Type I, II and III.

A study on the color stability of resin cements luted for porcelain laminate veneer / 대한치과보철학회지

STATEMENT OF PROBLEMS: Long-term success of esthetic restorations, depends on various factors, especially on color stability of the restorations. The color stability is affected by resin cements beneath the porcelain laminate veneers. PURPOSE: The purpose of this study was to comprehend the color stability of resin cements by comparing with 4 different kinds of resin cements (Choice, Variolink II, Nexus 2, Rely-X). MATERIAL AND METHODS: Porcelain laminate disk samples were luted with resin cements. After thermocycling of each 1000, 2000 and 3000 cycle, specimens were measured by spectrophotometers and the color differences were. RESULTS: 1. After thermocycling of 1000, 2000 and 3000cycle, color difference, (deltaE*) of all specimens were incresed, but were not statiscally significant differences. 2. In the Choice of A1 shade and the Nexus 2 of A3 shade, color difference(deltaE*) after thermocycling of 3000cycle was incre*ased significantly than after thermocycling of 1000cycle. However, other groups did not show any statistically significant differences (P<0.05). 3. After thermocycling of 3000cycle, color difference(deltaE*) between A1 shade and A3 shade of Nexus 2 showed statistically significant difference. However no statistically significant differences were observed in other groups (P<0.05). 4. The mean of color difference(deltaE*) is 1.0-2.06 after 3000 thermocycling and the data were ranked in the ascending order of Variolink II, Nexus 2, Choice and Rely-X in A1 shade group and Choice, Rely-X, Variolink II and Nexus 2 in A3 shade group. CONCLUSION: Above results revealed that, after 3000thermocycing, the color difference (deltaE*) of experimental resin cements was within clinically acceptable ranges. Color stability of 4 different resin cements was comparatively excellent.

The color comparison of various resin cements with try-in pastes used in porcelain laminate veneer / 대한치과보철학회지

STATEMENT OF PROBLEM: The color change of final restoration resulting from resin cement is variable since the amount of the tooth is prepared is minimum. PURPOSE: The purpose of this study was to compare the color accuracy of try-in paste and their corresponding resin cements and the color stability of restoration intermediated resin cement according to two shades of three products(Rely-X, Variolink II, Choice). MATERIAL AND METHOD: Color was measured for porcelain disk sample without try-in paste, and porcelain disk sample intermediated by try-in paste and resin cement, then color differences were calculated. RESULTS: 1. Color difference(delta E*) between try-in paste and resin cement showed the lowest value at Variolink II and increased in the order Choice and Rely-X statistically significant, and delta E* of three resin cements was greater in A3 then A1. 2. The values of delta L* and delta a* between try-in paste and resin cement was in the increasing order of Variolink II, Choice and Rely-X. The delta b* value was increased in this order Choice, Rely-X and Variolink II in A1, on the other hand Variolink II, Rely-X and Choice in A3. 3. Color difference(delta E*) before and after resin cement showed the lowest value at Variolink II and increased in the order Rely-X and Choice. CONCLUSION: Above result revealed that the colors of try-in paste and resin cement were more or less accurate in the range of 0.35-1.95 of color difference which was unnoticeable with human eye, and Variolink II was superior to the other resin cements in color accuracy.

Clinical evaluation of porcelain laminate veneer in front teeth / 中华医学美学美容杂志

Objective To evaluate the clinical performance of porcelain laminate veneer in front teeth. Metheds 79 porcelain laminate veneers in front teeth in 38 cases were observed after finished repair and 18-month follow-up. The evaluator examined the restoration for shade, surface lubricity, marginal fit, plaque index and gingival index. Results Shade satisfaction was 82 % and 87 %, surface lubricity satisfaction was 100 % and 100 %, marginal fit satisfaction 84 % after restoration and 18-month follow-up. The plaque index of experince atal groups was 0.73?0.45 and the gingival index of experinceatal groups was 0.28?0.67. There was no statistically significant difference with regard 82 % and to plaque index and gingival index. Conclusion The effect of porcelain laminate veneer in front teeth is satisfactory.