Microleakage in Class V Composite Restorations after Desensitizing Surface Treatment with Er:YAG and CO2 Lasers

Evaluation of the microleakage of class V composite restoration after cavity treatment with Erbium, CO2 lasers, Papain, and Bromelain enzymes

OBJECTVES

Different surface preparation and treatment methods may have dissimilar effects on the microleakage of composite resin. This study was conducted to determine the deproteinizing effect of 10% bromelain enzyme, 10% papain enzyme, CO2 , and erbium-YAG laser in regard to decrease in the microleakage of composite restorations.

MATERIALS AND METHODS

Thirty teeth were selected and 60 class V cavities were prepared on the lingual and buccal sides. They were divided into six groups (n = 10): Group 1, phosphoric acid gel; Group 2, bromelain enzyme 10%; Group 3, papain enzyme 10%; Group 4, mixed papain and bromelain enzymes 10%; Group 5, CO2 laser; and Group 6, erbium-YAG laser. They were stored in basic fuchsine and dye penetration was evaluated. Kruskal-Wallis and Mann-Whitney tests were used for statistical analysis, p < 0.05 RESULTS: In both occlusal and gingival margins, comparison of microleakage between groups 1, 2, 3, 4, and 5 showed no significant differences (p = 1) and group 6 had a significant difference with other groups (p ˂ 0.001).

CONCLUSIONS

Microleakage of composite resin in the dentin surface was not affected significantly using either bromelain or papain 10% enzymes or erbium laser. However, CO2 laser had a negative effect on the enamel and dentin margins and increased the microleakage. Erbium laser showed a better effect than enzymes on microleakage.

Effect of Various Lasers With or Without Systemp.desensitizer on Dentine Tubules: An In Vitro Scanning Electron Microscopy Analysis

Objective: The current study was carried out to evaluate the effects of laser and Systemp.desensitizer therapy. Further, scanning electron microscopy (SEM) was used to determine the effects of individual or combined desensitizers on human dentinal tubules. Background: The most common clinical condition that makes people uncomfortable is dentin hypersensitivity (DH). Both lasers and drugs that reduce sensitivity have been used to treat DH. Materials and methods: A total of 100 dentinal samples were taken from newly extracted third molars (affected) and divided into 10 groups (A to J), that is, control (A); Systemp.desensitizer (B); diode laser (980 nm) (C); Nd:YAG laser (D); Er:YAG laser (E); Er,Cr:YSGG laser (F); Systemp.desensitizer + diode laser (G); Systemp.desensitizer + Nd:YAG laser (H); Systemp.desensitizer + Er:YAG laser (I); and Systemp.desensitizer + Er,Cr:YSGG laser (J). SEM was used to evaluate the dentinal specimens in each group (longitudinal and transverse portions), and then images of each sample were captured (20 images/sample). In addition, the number of open dentinal tubules was counted and then the occlusion depth in dentinal tubules was measured. Mann-Whitney and Kruskal-Wallis tests were employed to analyze the obtained data. Results: All treatment procedures and protocols were effective in blocking dentinal tubules (p < 0.05). Compared with the other groups, dentinal tubules in the laser and laser combination therapy groups were significantly obstructed (p < 0.05). Diode and Nd:YAG lasers with or without Systemp.desensitizer showed significantly more tubule occlusion and greater sealing depth than Er:YAG and Er,Cr:YSGG lasers with or without Systemp.desensitizer (p < 0.05). Conclusions: In summary, lasers alone or in combination can play a significant role in occluding the dentinal tubules. However, combining the diode or Nd:YAG laser with Systemp.desensitizers is a more effective treatment strategy and may have immediate and long-lasting effects.

In Vitro Analysis of Quality of Dental Adhesive Bond Systems Applied in Various Conditions

Introduction: There are several methods of reducing a microleakage, and one of them is choosing appropriate adhesive material. The aim of the work was the in vitro analysis of 4 bonds: 3M ESPE “Single bond”, Dentsply “Prime and Bond Active”, Coltene “One Coat 7 Universal”, and Kuraray “Clearfil Universal Bond Quick”. Material and methods: 136 healthy molar teeth were collected and randomly split into 4 groups and Vth Class cavities were prepared. Chosen adhesives were used in four groups of teeth with the same composite. Teeth were the thermocycled, sealed, covered with lacquer, and submerged in 1% methylene blue solution for 24 h. After the thermocycling, the vertices of each tooth were sealed using dental wax. Each tooth was then fully covered with lacquer. All teeth were then submerged into 1% methylene blue solution for 24 h in room temperature. In the next step they were transversely cut through a center of restoration. The Olympus BX43 microscope was used to photograph each cut tooth. With the usage of Olympus stream software, measurement of the dye’s leakage was performed. Results. The statistical analysis proved that the most effective material when applied to ideally prepared cavity surface was Dentsply “Prime and Bond Active”. The second material was 3M ESPE “Single Bond”, third—Coltene “One Coat 7 Universal” and fourth—Kuraray “Clearfil Universal Bond Quick”. The most effective material applied to a too-dry surface was Dentsply “Prime and Bond Active”, second—3M ESPE “Single Bond”, third—Coltene “One Coat 7 Universal” and fourth—Kuraray “Clearfil Universal Bond Quick”. When it comes to too damp surfaces the best results were obtained with Dentsply “Prime and Bond Active” then Coltene “One Coat 7 Universal”, 3M ESPE “Single Bond” and Kuraray “Clearfil Universal Bond Quick”. Conclusion: The level of cavity dampness influences the quality of adhesives. Better results are obtained with over-dried surfaces than over-damp, which is connected with the dilution of the material.

Effect of Er:YAG laser energy densities on thermally affected dentin layer: Morphological study

BACKGROUND AND AIMS

Physical and chemical composition of dentin is subject to modification when irradiated with Er:YAG laser. Temperature rise causes water evaporation and micro-mechanical ablation of dentin. The misuse of laser parameters could affect negatively dentin collagen fibers leading to failure in bonded composite restorations. The aim of this in vitro study was to evaluate the effect of Er:YAG laser radiation at different levels of energy on the morphology of thermally affected dentin layer.

MATERIALS AND METHODS

Forty-eight freshly extracted human third molars were randomly divided into six groups (n = 8). In all groups, except for the control groups, dentin was subject to irradiation with H02 handpiece Er:YAG laser in non-contact mode (SSP mode = 50 µs; 10 Hz; speed of 1 mm/second; air 6 mL/min; and water 4 mL/min) with the following levels of energy (40, 60, 80, 100, and 120 mJ) respectively. Teeth were sliced longitudinally. Photo-ablated cavities were observed. The cavity depth and dentin fiber collagen deterioration were measured.

RESULTS

Laser irradiation increased the depth of dentinal crater from 46.57 µm to 178.2 µm, when energy level increased from 40 mJ to 120 mJ. A superficial black layer, representing dentinal affected collagen fibers, was present in all groups except for control group. When comparing the thickness of the black layer, there was no significant difference between groups. It increased at 40 mJ to 28.17 µm then decreased to 15.19 µm at 60 mJ and then increased again for 80 mJ to 19.93 µm, 100 mJ to 22.87 µm and 120 mJ to 28.53 µm. Only one group (60 mJ) showed low values and significant difference as compared to the other irradiated groups, when multiple comparisons tests (ANOVA) were made using Newman-Keuls test.

CONCLUSION

Dentin organic matrix presented the minimum alteration when Er:YAG laser is used specifically at an appropriate level of energy (60 mJ).

Evaluation of the effects of Er:YAG laser, Nd:YAG laser, and two different desensitizers on dentin permeability: in vitro study

The purpose of this in vitro study was to evaluate and compare the efficacy of erbium-doped yttrium aluminum garnet (Er:YAG) laser, neodymium-doped yttrium aluminum garnet (Nd:YAG) laser, PrevDent nano-hydroxyapatite toothpaste plus Repairing Serum Kit (PNH), and NUPRO Sensodyne Prophylaxis Paste with NovaMin (NPP) on dentin permeability reduction. Forty dentin discs obtained from bovine incisors were divided into four study groups: Er:YAG laser-treated (2940 nm; 0.2 W, 80 mJ/pulse, 3 Hz); Nd:YAG laser-treated (1064 nm; 1 W, 10 Hz); PNH-treated; and NPP-treated groups. The quantitative changes in permeability of each dentin disc were measured using a computerized fluid filtration method (CFFM) before and after desensitizer treatments. The data were analyzed using the Wilcoxon, paired-samples t, Kruskal-Wallis, and Mann-Whitney U tests. The dentin surfaces and tubules were also morphologically detected by scanning electron microscopy (SEM). In all groups, dentin permeability was significantly reduced after the desensitizer and laser treatments (p < 0.05). Among the groups, we detected a significant difference in only when comparing the Er:YAG laser- and NPP-treated groups (p = 0.034). SEM analysis revealed physical changes in the dentin surface in all groups. This in vitro study shows that all tested desensitizers and laser treatments reduced dentin permeability. Also, surface changes, such as complete or partial occlusion or shrinkage of dentin tubules, were observed in all groups. Although the laser groups performed best, the PNH protocol can be considered as an alternative therapeutic product. In addition, clinical and laboratory studies should be performed for this product, and their efficacy should be assessed by combined therapy with lasers.