Use of fluorescent compounds in assessing bonded resin-based restorations: a literature review

OBJECTIVES: This work reviews fundamental concepts involved with fluorescent imaging in the dental materials field. DATA: Fluorescent dyes have been widely used: incorporated into adhesive system components, placed in the pulp chamber and allowed to diffuse toward the restorative interface, as well as used as a visible tracer in microleakage tests. CONCLUSIONS: Although use of fluorescent imaging has substantially contributed to the existing knowledge base, there is no standardized methodology used, and as a result, interpretation of study results as well as comparison of results among studies remains questionable.     

IN VITRO STUDY OF THE EFFECT OF ER:YAG LASER IRRADIATION ON THE APICAL SEALING OF DIFFERENT ROOT CANAL SEALERS

Objectives:

The aim of this study was to determine the effect of Er:YAG laser irradiation used to clean dentinal walls on the apical sealing of root canals filled with different types of sealers.

Background Data:

Laser application to the dentinal walls removed debris, rendering the root canals free of smear layers and leaving the dentinal canaliculi open.

Methods:

Sixty-four maxillary canines obtained from laboratory files were instrumented with K-files (Dentsply, Maillefer, Ballaigues, Switzerland) using the crown-down technique, and irrigated with a 0.5% sodium hypochlorite solution. The specimens were divided into two groups of 32 teeth each. In group I, the teeth were instrumented and irrigated with sodium hypochlorite solution, and divided into four subgroups to be sealed with the different materials (Endofill, N-Rickert, Sealapex and Sealer 26). In group II, the root canals were subjected to Er:YAG laser irradiation (200 mJ, 7 Hz and 60 J total energy), followed by root canal sealing as in group I.

Results:

The data showed lower levels of apical microleakage in the teeth filled with N-Rickert, Sealapex and Sealer 26 cements than in those sealed with Endofill (p < 0.01). No significant difference in microleakage was observed between teeth irrigated only with 0.5% sodium hypochlorite and those submitted to Er:YAG laser application (p > 0.05).

Conclusions:

The Er:YAG laser irradiation applied to the root canal walls was not able to prevent apical microleakage.     

Influence of cavity dimensions, insertion technique and adhesive system on microleakage of Class V restorations

BACKGROUND: The authors evaluated the influence of cavity dimensions, insertion technique and adhesive system on microleakage of Class composite restorations. METHODS: The authors prepared cylindrical cavities with enamel margins of 3-millimeter diameter by 1-mm depth or 6-mm diameter by 2-mm depth on the labial surface of bovine incisors. They defined experimental groups (n = 15) according to cavity size, insertion technique (bulk or incremental) and adhesive system applied (Single Bond, 3M ESPE, St. Paul, Minn., or Excite, Ivoclar Vivadent, Amherst, N.Y.). They restored preparations with Tetric Ceram (Ivoclar Vivadent). After 36 hours' storage in distilled water at 37 C, specimens were submitted to microleakage using 50 percent silver nitrate as tracer. Teeth were sectioned twice and dye penetration on the axial wall was determined in millimeters. RESULTS: The authors analyzed the data using analysis of variance/Tukey test (a = .05). For large restorations, the use of Single Bond resulted in higher microleakage than Excite (1.56 +/- standard deviation [SD] 0.26 mm and 0.63 +/- SD 0.56 mm, respectively; P < .001), whereas for small restorations there was no statistical difference between adhesives (Excite: 0.47 +/- SD 0.28 mm; Single Bond: 0.46 +/- SD 0.28 mm). CONCLUSION: The choice of adhesive system influenced microleakage only for large restorations. Incremental insertion of the composite did not affect dye penetration. CLINICAL IMPLICATIONS: Microleakage of composite restorations cannot be predicted only on the basis of the restorations' dimensions. In large restorations, it also depends on the choice of adhesive system, whereas in small restorations, the adhesive used does not seem to be an influential factor. Incremental insertion did not seem to reduce restorations' microleakage.     

Laser Florence 2009

In this study, we compared the microleakage of composite fillings cured with halogen bulb, LED and argon ion laser (488 nm). Twenty-four extracted human molars were divided randomly in three groups. Six cavities were prepared on the coronal part of each tooth. Standard cavities (1.7 × 2 mm) were prepared. Cavities were acid etched, sealed with Scotch Bond 1 and filled by a hybrid composite. Cavities were exposed to one light source, thermocycled and immersed in a 2% methylene blue dye solution. Dye penetration in the leakage of cavities was recorded using a digital optical microscope. Mean values of percentage of dye penetrations in microleakages of cavities were 49.303 ± 5.178% for cavities cured with LED, 44.486 ± 6.075% with halogen bulb and 36.647 ± 5.936% for those cured by argon laser. Statistically significant difference exists between cavities cured by halogen vs LED (P < 0.01), halogen vs laser (P < 0.001) and LED vs laser (P < 0.001). The lowest microleakage was observed in the cavities and composites cured with argon ion laser.     

纤维桩系统的回顾和进展

桩核冠修复是根管充填治疗后牙齿外形重建的最主要手段之一。近几十年铸造合金桩核冠及预成金属桩加核加冠成了牙体缺损修复的主流方式，但是由于其自身存在诸多缺点限制了其在临床上的应用。自从90年代碳纤维桩问世以来，由于其自身特点得到了临床医生的青睐，随后又出现了玻璃纤维桩和石英纤维桩，聚乙烯纤维增强的树脂桩。目前玻璃纤维桩成为了纤维桩修复的主流，但是同样存在着自身缺点，这使得研究人员致力研发新一代的纤维桩，如石英纤维桩。本文回顾了纤维桩的发展过程、纤维桩的分类、最新一代的纤维桩的优点、临床操作所需要的材料和器械及所需要注意的问题。     

三种根充糊剂的根管封闭性比较研究

目的比较氧化锌丁香油糊剂、vitapex糊剂和cortisomol糊剂根充后根管侧壁和根尖区的微渗漏情况,评价三种根充糊剂根充时对于根管侧壁及根尖区的封闭性能。方法分别使用三种根充糊剂充填单根管离体牙后,染色,片切,测量染液自根尖和根管侧壁渗入的长度。结果对比染液自根尖渗入微渗漏长度数值,cortisomol糊剂组微渗漏长度数值低于氧化锌丁香油糊剂组（P〈0.001）,vitapex糊剂组低于氧化锌丁香油糊剂组（P〈0.001）,cortisomol糊剂组微渗漏长度数值低于vitapex糊剂组（0.02〈P〈0.05）;对比染液自根管侧壁渗入微渗漏长度数值,cortisomol糊剂组微渗漏长度数值低于氧化锌丁香油糊剂组（P〈0.001）,vitapex糊剂组低于氧化锌丁香油糊剂组（P〈0.001）,cortisomol糊剂组微渗漏长度数值低于vitapex糊剂组（0.01〈P〈0.02）。结论cortisomol糊剂的根管封闭性能无论在根尖还是根管侧壁均优于vitapex糊剂和氧化锌丁香油糊剂,vitapex糊剂的根管封闭性能又优于传统的氧化锌丁香油糊剂。     

Microleakage of class V composite restorations following Er:YAG and Nd:YAP laser irradiation compared to acid-etch: an In vitro study

. This study compared microleakage at enamel/composite and dentine/composite interfaces following Er:YAG laser, Nd:YAP laser, or acid-etch preparation. Class V cavities produced on the lingual and buccal surfaces of 20 extracted carie- and restoration-free human teeth were randomly assigned to four groups of 10 cavities. Teeth were treated with 37% phosphoric acid and primer (group 1), irradiated with an Er:YAG laser (group 2) or an Nd:YAP laser (group 3), or served as controls (group 4). The specimens were restored with Scotchbond Multipurpose/Z100 (3M), stored in physiological solution at 37°C for 7 days, thermocycled 500 times between 5°C and 55°C, placed in a 0.5% solution of basic fuchsin for 48 h, embedded in resin, and sectioned. Microleakage was assessed according to the depth of dye penetration along the restorative composite. The results showed that irradiation with Er:YAG and Nd:YAP lasers did not produce a good seal. Mean microleakage was greater than with acid-etch and statistically comparable to that of control cavities (Kruskal–Wallis test). Paper received 18 January 2001; accepted after revision 28 September 2001.     

树脂对种植义齿固定螺丝孔的封闭作用

目的用定量测定葡萄糖含量的方法检测种植义齿固定螺丝孔的微渗漏,并比较4种光敏树脂对固定螺丝孔的封闭性。方法首先制备80个钛合金中空半圆柱体试件(高6mm,上部1/2厚度=0·5mm,下部1/2厚度=1mm,内直径3mm,上1/2表面烤瓷0·5mm),其次试件内表面喷砂+瓷层酸蚀处理后分成4组,分别用4种光敏树脂进行封闭,用葡萄糖氧化酶-过氧化物酶法(GOD-POD法)测定各组微渗漏情况。结果4组试件间微渗漏差异有统计学意义(P<0·01)。结论封闭材料是影响固定螺丝孔微渗漏的一个重要因素;GOD-POD法是一种能定量测定种植义齿固定螺丝孔微渗漏的方法。