Effect of laser application on microtensile bond strength of an orthodontic adhesive to water-aged composite

Aim

This study evaluated the microtensile bond strength (MTBS) of an orthodontic adhesive to water-aged composite surfaces using different surface treatments.

Subjects and Methods

Twelve composite blocks (10 mm × 10 mm × 5 mm) were fabricated and randomly divided into two groups. Half of the specimens were stored in distilled water for 1 day, and the other specimens were stored for 30 days. The specimens were randomly assigned to six groups according to surface treatments (n = 15): Group 1, control (no treatment); Group 2, phosphoric acid; Group 3, diamond bur; Group 4, diamond bur + phosphoric acid; Group 5, laser; and Group 6, laser + phosphoric acid. One coat of orthodontic adhesive was bonded to one surface of composite blocks, and a microhybrid composite resin was bonded to the surfaces via a Teflon mold. Bond strength was evaluated using an MTBS test. Surface topography was evaluated using scanning electron microscopy (SEM) analysis. The data were analyzed using one-way analysis of variance, Tamhane post-hoc test, and independent sample t-tests (P < 0.05).

Results

Bond strength values tended to decrease in all groups (with the exception of Group 2) after storage in water for 30 days (P < 0.05). Laser and diamond bur application (with or without phosphoric acid) enhanced the bond strength.

Conclusions

An Er,Cr:YSGG laser application may be a feasible alternative to diamond bur for enhancing the bond strength of orthodontic adhesive to composite resin.

The effects of cavity disinfection on the nanoleakage of compomer restorations: an in vitro study

Purpose:

Cavity disinfection, in addition to routine caries removal methods, is recommended to eliminate the microorganisms. The aim of this study was to compare the effect of various systems Er,Cr:YSGG lasers, diode lasers and FotoSan and agents Corsodyl; Cervitec and Cervitec Plus and Fluor Protector—on the nanoleakage of compomer restorations when used for cavity disinfection.

Materials and methods:

A total of 40 intact human deciduous molar teeth containing Black V cavities (3×2×1.5 mm) on the buccal and lingual surfaces parallel to the cementoenamel junction were randomly divided into 8 groups according to the cavity disinfection methods. The antibacterial agents and systems were applied according to the manufacturer’s instructions. Restorations were completed using a compomer. The restored teeth were then subjected to thermocycling for 500 cycles in a water bath at 5°C and 55°C with a dwell time of 30 seconds. After the thermocycling procedures, 1-mm sticks were obtained from the center of each cavity to prepare for the nanoleakage test. After the teeth were sectioned, they were immersed in 50 wt % ammoniacal silver nitrate solution for 24 hours and dipped in photo-developing solutions for 8 hours with fluorescent light irradiation. The samples were examined under a scanning electron microscope (SEM). The non-parametric Kruskal-Wallis and Mann-Whitney U test (p<0.05) were applied.

Results:

The Er,Cr:YSGG laser group showed significantly less nanoleakage than all of the tested groups (p<0.01). The diode laser, Fluor protector and FotoSan groups showed similar nanoleakage to that of the control group (p>0.05). The Corsodyl (p<0.01) and Cervitec (p<0.001) groups showed significantly higher nanoleakage than the control group.

Conclusion:

Er,Cr:YSGG laser irradiation which showed lower nanoleakage scores from either control or tested groups can be recommended for cavity disinfection Additionally, a diode laser and FotoSan, which have antibacterial effects and no negative effect on leakage, can be used for cavity disinfection.

Effect of Fiber Laser Irradiation on the Shear Bond Strength between Acrylic Resin and Titanium

OBJECTIVES

The aim of this study is to investigate the shear bond strength of an acrylic resin to titanium after different surface treatment methods.

MATERIAL AND METHODS

A total of seventy-two disc-shaped specimens (10 mm × 10 mm × 2 mm) were prepared from titanium alloy. The specimens were randomly allocated to six equal groups: Group S (sandblasting), Group MP (metal primer), Group 10W (fiber laser 10 W), Group 20W (fiber laser 20 W), Group 10WMP (fiber laser 10 W+metal primer), and Group 20WMP (fiber laser 20 W+metal primer). All of the specimens were thermocycled up to 5000 cycles. After thermal cycling, a shear bond strength test was conducted. The shear bond strength data were analyzed with one-way ANOVA and Tukey's post hoc pairwise comparisons (p < 0.05).

RESULTS

While the highest values were determined in Group MP, the lowest values were observed in Group S. Additionally, Group MP exhibited significantly higher shear bond strength values than any of the other groups (p < 0.05) except Group 10WMP. Similar results were observed between Group MP and Group 10WMP (p > 0.05). The groups in which a metal primer was applied (Group MP, 10WMP, and 20WMP) showed significantly higher values than Group S. The shear bond strength values of Group 10W and Group 20W were similar.

CONCLUSIONS

The application of a metal primer significantly improved the bond strength of acrylic resin to titanium. Fiber laser application may be an alternative method to sandblasting for improving the bond strength of acrylic resin to titanium.

Antimicrobial activity and volatile constituent analysis of three commercial herbal toothpastes containing Aloe vera L. and Fragaria vesca L. extracts

AIMS

This work was designed to evaluate the antimicrobial activity of three different commercial herbal (Aloe vera L. and Fragaria vesca L. extracts) toothpastes [LR Aloe vera (HTP1), ESI Aloe fresh (HTP2) and ROCS Teens (HTP3)] against two microorganisms that cause tooth infections.

MATERIALS AND METHODS

An agar disk diffusion method was used to test the antimicrobial activity of three herbal gel toothpastes in the amount of 100 μL against Streptococcus mutans and Staphylococcus aureus. In the second part of the work, the volatile organic compounds of three different commercial herbal toothpastes (HTP1-3) were determined by solid-phase microextraction/gas chromatography-mass spectrometry-flame ionization detection (SPME/GC-MS-FID).

RESULTS

The sensitivity of the tested herbal toothpastes toward each microorganism was expressed as the mean of the clear zone within the range of 6-16 mm diameters. HTP1 and HTP2 were found to be more effective against both bacteria compared with HTP3. Oxygenated monoterpenes (99.34%, 91.44%, and 83.48%) were the most abundant groups in the SPME of HTP1-3, respectively. Menthol (25.41%, 35.82%, and 31.15%) and anethole (52.01%, 23.62%, and 38.79%) were the major compounds identified in the SPME analysis of HTP1-3, respectively. Carvone was found only in HTP3 (0.49%) in a small quantity.

CONCLUSION

The commercial herbal toothpastes could have advantages in decreasing bacterial accumulation on teeth with protection of the oral cavity.

Evaluation of the knowledge, attitudes and behaviors of pre-school teachers on oral and dental health in the city center of Trabzon

Purpose:

Educators can also contribute to the prevention of early childhood caries (ECC) by educating children about oral diseases and hygiene practices. The aim of this study was to assess the knowledge, attitudes, and behaviors of pre-school teachers concerning oral and dental health in Trabzon.

Subjects and methods:

The study was carried out with 226 pre-school teachers in the city center using a self-administered questionnaire to evaluate their knowledge, attitudes, and behaviors concerning the oral and dental health of children.

Results:

Only 29.8% of the respondents had a prior dental education. Although 83% of the teachers said that regular visits to the dentist were effective for caries prevention, only 13.2% said that they made regular visits to a dentist. Approximately 65.8% of the teachers agreed that fluoride strengthens tooth enamel and 35.1% of the teachers said that there were oral health activities in their schools. Additionally, 74.6% of teachers said that they would participate in dental education about children’s oral health in the future.

Conclusion:

Preventive dental health program could be implemented including the proper behaviors related to the importance and treatability of primary teeth, first tooth cleaning, dental visits, the use of fluoride toothpaste, and oral hygiene into the pre-school teachers’ undergraduate education programs in the future. This program should be repeated at certain intervals for the prevention of ECC.

Peri-implant plastic surgery techniques to hard and soft tissue augmentation in implant rehabilitation

This report presents the clinical results of peri-implant plastic surgical approaches for hard and soft tissues before and during the implant placement in a patient with vertical ridge deformation and a shallow vestibule sulcus, and the subsequently performed prosthetic rehabilitation. The surgical approaches used in this case reduced the crown-height space and crown-to-implant ratio and ensured that the implants were placed in their ideal positions, and peri-implant tissue health was maintained. In conclusion, developments in the peri-implant plastic surgery enable the successful augmentation of hard and soft tissue defects and provide the implant-supported fixed prosthetic rehabilitation.

The effect of ultrafast fiber laser application on the bond strength of resin cement to titanium

The purpose of this study was to investigate the effect of ultrafast fiber laser treatment on the bond strength between titanium and resin cement. A total of 60 pure titanium discs (15 mm × 2 mm) were divided into six test groups (n = 10) according to the surface treatment used: group (1) control, machining; group (2) grinding with a diamond bur; group (3) ultrafast fiber laser application; group (4) resorbable blast media (RBM) application; group (5) electro-erosion with copper; and group (6) sandblasting. After surface treatments, resin cements were applied to the treated titanium surfaces. Shear bond strength testing of the samples was performed with a universal testing machine after storing in distilled water at 37 °C for 24 h. One-way ANOVA and Tukey's HSD post hoc test were used to analyse the data (P < 0.05). The highest bond strength values were observed in the laser application group, while the lowest values were observed in the grinding group. Sandblasting and laser application resulted in significantly higher bond strengths than control treatment (P < 0.05). Ultrafast fiber laser treatment and sandblasting may improve the bond strength between resin cement and titanium.

A combined peri-implant plastic surgery approach for implants in the esthetic zone using a novel technique: A series of 10 cases

OBJECTIVE

In this study, 12-month follow-up clinical results of a combined peri-implant plastic surgery approach for hard and soft tissue augmentation in implant rehabilitation in the esthetic zone are presented.

METHOD AND MATERIALS

Ten individuals who required extraction due to severe periodontal destruction in the maxillary and mandibular area were included in the study. Implant surgery was performed in the same session as the combined peri-implant plastic surgeries, which involved guided bone regeneration and free periosteal grafts. Prosthetic treatment was administered in the sixth month following the surgeries.

RESULTS

Hard and soft tissue augmentation with sufficient keratinized mucosa width (≥ 2 mm) was achieved with the combined surgical approaches. Pleasing esthetic results were obtained by careful positioning of the implants.

CONCLUSIONS

In implant rehabilitation, in cases where there are insufficient hard and soft tissues in the esthetic zone, a combined peri-implant plastic surgery approach not only enables the ideal implant position where both function and esthetics are ensured but also provides effective protection of peri-implant tissue health.

Release of cetyl pyridinium chloride from fatty acid chelate temporary dental cement

Objective To determine whether the antimicrobial nature of a fatty acid chelate temporary dental cement can be enhanced by the addition of 5% cetyl pyridinium chloride (CPC).

Materials and methods The temporary cement, Cavex Temporary was employed, and additions of CPC were made to either the base or the catalyst paste prior to mixing the cement. Release of CPC from set cement specimens was followed using reverse-phase HPLC for a period of up to 2 weeks following specimen preparation. Potential interactions between Cavex and CPC were examined by Fourier transform infrared spectroscopy (FTIR) and antimicrobial effects were determined using zone of inhibition measurements after 24 h with disc-shaped specimens in cultured Streptococcus mutans.

Results FTIR showed no interaction between CPC and the components of the cement. CPC release was found to follow a diffusion mechanism for the first 6 h or so, and to equilibrate after approximately 2 weeks, with no significant differences between release profiles when the additive was incorporated into the base or the catalyst paste. Diffusion was rapid, and had a diffusion coefficient of approximately 1 × 10⁻⁹ m² s⁻¹ in both cases. Total release was in the range 10–12% of the CPC loading. Zones of inhibition around discs containing CPC were significantly larger than those around the control discs of CPC-free cement.

Conclusions The antimicrobial character of this temporary cement can be enhanced by the addition of CPC. Such enhancement is of potential clinical value, though further in vivo work is needed to confirm this.

Peri-Implant Plastic Surgical Approaches to Increasing Keratinized Mucosa Width: Which to Use and When?

The long-term efficacy of adequate keratinized mucosa (&gt;2 mm) in dental implants is controversial. Peri-implant plastic surgeries are currently used because they increase keratinized mucosa width (KMW), helping to regain peri-implant health and maintaining it over the long-term. We present the clinical findings using free-gingival-graft (FGG) and free-periosteal-graft (FPG) techniques in peri-implant plastic surgery for implant rehabilitation patients. We included 20 patients with implant indications of inadequate KMW (KMW &lt; 2 mm for postimplantation) in the maxilla and mandible. All underwent clinical and radiographic measurements and a treatment protocol was prepared for implant rehabilitation and subsequent peri-implant plastic surgery. A decision as to whether and when FGG or FPG techniques would be used was made. FGG/FPG was performed pre-implantation (before monocortical block-bone augmentation) or postimplantation (before/during/after stage 2 surgery). KMW was ≥ 2 mm after application of FGG/FPG pre- or post-implantation. Moreover, peri-implant tissue health was regained/maintained in all cases from 6 months to 4 years. Peri-implant plastic surgery techniques can prevent hard- and soft-tissue problems after implant rehabilitation and during treatment of developing problems. However, surgical design and timing, and an interdisciplinary perspective determine the success of peri-implant plastic surgery.

Combined soft and hard tissue peri-implant plastic surgery techniques to enhance implant rehabilitation: a case report

This case report presents an implant-aided prosthetic treatment in which peri-implant plastic surgery techniques were applied in combination to satisfactorily attain functional aesthetic expectations. Peri-implant plastic surgery enables the successful reconstruction and restoration of the balance between soft and hard tissues and allows the option of implant-aided fixed prosthetic rehabilitation.

The effect of an erbium, chromium: yttrium-scandium-gallium-garnet laser on the microleakage and bond strength of silorane and micro-hybrid composite restorations

Objective:

The aim of this in vitro study was to compare the microleakage and bond strength of Class V silorane-based and universal micro-hybrid composite restorations prepared either with diamond bur or with an erbium, chromium: yttrium-scandium-gallium-garnet (Er, Cr:YSGG) laser.

Materials and Methods:

A total of 160 molar teeth were used for microleakage assessment and shear bond strength (SBS) test. The specimens were prepared using either diamond bur or 3 W-, 4 W- and 5 W-20 Hz Er, Cr:YSGG laser irradiation. All specimens were subjected to thermocycling (500 times at 5 ± 2°C to 55 ± 2°C, dwell time 15 s and transfer time 10 s). Microleakage was assessed using a 0.5% basic-fuchsin solution. The bond strengths were determined using a microtensile tester at a crosshead speed of 0.5 mm/min. The Kruskal Wallis test was used for the analysis of microleakage and a one-way analysis of variance test was used to analyze the SBS (P < 0.05).

Results:

No statistically significant differences were found (P > 0.05) between Er, Cr:YSGG laser and bur preparation methods regarding microleakage and bond strength values.

Conclusion:

Irradiation with Er, Cr:YSGG laser was confirmed to be as effective as conventional methods for preparing cavities before adhesive restorations.

Do surface treatments affect the optical properties of ceramic veneers?

STATEMENT OF PROBLEM

Surface treatments may affect the optical properties of ceramic veneers before cementation.

PURPOSE

The purpose of this study was to evaluate whether various surface treatments affect the optical properties of different types of ceramic veneers.

MATERIAL AND METHODS

Disk-shaped ceramic veneers (N=280) were prepared from the IPS e.max Press, e.max CAD, Empress Esthetic, e.max Ceram, and Inline ceramic systems with 0.5-mm and 1.0-mm thicknesses. The ceramics were divided into 4 groups: no surface treatments; etched with hydrofluoric acid; airborne-particle abraded with 30-μm Al2O3; and irradiated with erbium:yttrium-aluminum-garnet laser. A translucent shade of resin was chosen for cementation. Color parameters were examined with a colorimeter. Statistical analyses were done with 3-way ANOVA and the Bonferroni test (P=.05).

RESULTS

Significant interactions were noted between the surface treatments, ceramic type, and thickness for ΔE values (P=.01), and no significant interactions were noted for L* (P=.773), a* (P=.984), and b* (P=.998). The greatest color change occurred after airborne-particle abrasion with 0.5-mm-thick e.max Press (2.9 ΔE). Significant differences in ΔE values were found among the hydrofluoric acid, airborne-particle abrasion, and laser groups for 0.5-mm-thick ceramics, except IPS Inline, and among the hydrofluoric acid, airborne-particle abrasion, and laser groups for 1.0-mm-thick ceramics, except Empress Esthetic ceramics.

CONCLUSIONS

The color change of the ceramics increased after the surface treatments, particularly as the ceramics became thinner.

How will surface treatments affect the translucency of porcelain laminate veneers?

PURPOSE

The purpose of this study was to evaluate whether surface treatments affect the translucency of laminate veneers with different shades and thicknesses.

MATERIALS AND METHODS

A total of 224 disc-shaped ceramic veneers were prepared from A1, A3, HT (High Translucent) and HO (High Opaque) shades of IPS e.max Press (Ivoclar Vivadent) with 0.5 mm and 1.0 mm thicknesses. The ceramics were divided into four groups for surface treatments. Group C: no surface treatments; Group HF: etched with hydrofluoric acid; Group SB: sandblasted with 50-µm Al₂O₃; and Group L; irradiated with an Er;YAG laser. A translucent shade of resin cement (Rely X Veneer, 3M ESPE) was chosen for cementation. The color values of the veneers were measured with a colorimeter and translucency parameter (TP) values were calculated. A three-way ANOVA with interactions for TP values was performed and Bonferroni tests were used when appropriate (α=0.05).

RESULTS

There were significant interactions between the surface treatments, ceramic shades and thicknesses (P=.001). For the 0.5-mm-thick specimens there were significant differences after the SB and L treatments. There was no significant difference between the HF and C treatments for any shades or thicknesses (P>.05). For the 1-mm-thick ceramics, there was only a significant difference between the L and C treatments for the HT shade ceramics (P=.01). There were also significant differences between the SB and C treatments except not for the HO shades (P=.768).

CONCLUSION

The SB and L treatments caused laminate veneers to become more opaque; however, HF treatment did not affect the TP values. When the laminate veneers were thinner, both the shade of the ceramic and the SB and laser treatments had a greater effect on the TP values.

Peel strength of denture liner to PMMA and polyamide: laser versus air-abrasion

PURPOSE

This study investigated the effect of laser parameters and air-abrasion on the peel strength of silicon-based soft denture liner to different denture resins.

MATERIALS AND METHODS

Specimens (N=180) were prepared out of three different denture base resins (Rodex, cross-linked denture base acrylic resin; Paladent, heat-cured acrylic resin; Deflex, Polyamide resin) (75 mm × 25 mm × 3 mm). A silicon-based soft denture liner (Molloplast B) was applied to the denture resins after the following conditioning methods: a) Air-abrasion (50 µm), b) Er,Cr:YSGG laser (Waterlase MD Turbo, Biolase Technology) at 2 W-20 Hz, c) Er,Cr:YSGG laser at 2 W-30 Hz, d) Er,Cr:YSGG laser at 3 W-20 Hz, e) Er,Cr:YSGG laser at 3 W-30 Hz. Non-conditioned group acted as the control group. Peel test was performed in a universal testing machine. Failure modes were evaluated visually. Data were analyzed using two-way ANOVA and Tukey's test (α=.05).

RESULTS

Denture liner tested showed increased peel strength after laser treatment with different parameters (3.9±0.4 - 5.58±0.6 MPa) compared to the control (3.64±0.5 - 4.58±0.5 MPa) and air-abraded groups (3.1±0.6 - 4.46±0.3 MPa), but the results were not statistically significant except for Paladent, with the pretreatment of Er,Cr:YSGG laser at 3 W-20 Hz. Polyamide resin after air-abrasion showed significantly lower peel strength than those of other groups (3.1±0.6 MPa).

CONCLUSION

Heat-cured acrylic resin, PMMA, may benefit from Er,Cr:YSGG laser treatment at 3 W-20 Hz irradiation. Air-abrasion of polyamide resins should be avoided not to impair their peel bond strengths to silicon-based soft denture liners.

Comparative effects of denture cleansers on physical properties of polyamide and polymethyl methacrylate base polymers

The purpose of this study was to evaluate the effect of denture cleansers on the surface roughness, hardness and color stability of two polyamides (Valpast, Deflex), a butadiene styrene copolymer PMMA (Rodex), and PMMA polymer as a control group (Paladent). Each material was divided into 5 sub-groups (n=7) as two control and three test groups. Three test groups were immersed for 20 days in commercially available three denture cleansers (CO-Corega, PR-Protefix, VA-Valclean). Two-way analysis of variance and Tukey's post hoc HSD test were used to evaluate surface roughness and hardness data (α=0.05). ΔE, ΔL*, Δa*and Δb* mean values were used for ANOVA, Tamhane test was used as post hoc. Polyamides showed low hardness and high roughness before and after immersion. A significant decrease in hardness was observed for all resins except Rodex after immersion (p<0.05). The denture cleansers changed the roughness, hardness and color of some resins.

Discoloration of provisional restorations after oral rinses

PURPOSE

Oral rinses are widely used to promote periodontal health with provisional restorations during the interim period. The aim of this study was to compare the discoloration of provisional restoration materials with different oral rinses.

MATERIAL AND METHODS

A total of 140 disc-shaped specimens (shade A2) (10 mm x 2 mm) were prepared from one PMMA-based (TemDent Classic(®)) and three different bis-acrylic-based (Protemp II(®), Luxatemp(®) and Fill-In(®)) provisional restoration materials (n=7). The color values (L*, a*, and b*) of each specimen were measured before and after exposure with a colorimeter, and the color changes (∆E) were calculated according to the CIE L*a*b* system. The specimens were immersed in each of the 4 oral rinses (alcohol-containing mouthwash, chlorhexidine, benzydamine HCl, benzydamine HCl and chlorhexidine) twice a day for 2 minutes. After 2 minutes of immersion in the oral rinses, the specimens were immersed in artificial saliva. The specimens were exposed to the oral rinses and the artificial saliva for 3 weeks. Two-way ANOVA, the Bonferroni test and the paired sample t-test were used for statistical analyses (p<0.05).

RESULTS

Comparison of the discoloration from the oral rinses after immersion for three weeks revealed no significant differences (p>0.05). The lowest color change was observed in PMMA-based Temdent in all oral rinses (p<0.05). There were no significant differences between the bis-acryl composites after immersion in saliva or the mixture of benzydamine HCl and chlorhexidine and the alcohol-containing mouthwash for 3 weeks (p>0.05). After immersion in chlorhexidine, the color change values of Protemp II and Fill-in showed significant differences (p=0.018). Protemp II also showed less discoloration than the other bis-acryl composites, and this color change was statistically significant (p <0.05). For all oral rinses, the L* value decreased while b* values increased, and this color change was found to be statistically significant (p <0.05). A* values were found to be significantly higher with oral rinses (p<0.05), except Protemp II immersed in benzydamine HCl or alcohol-containing mouthwash.

CONCLUSIONS

The type of the oral rinse did not affect the discoloration process. For long-term esthetic results, choosing MMA-based materials for provisional restorations appears to be more effective.

Complicated subgingivally fractured central and lateral incisors: case report

Dental trauma sometimes causes fractures in the maxillary anterior teeth leading to esthetic, functional and phonetic problems. In this report, we describe the treatment of central and lateral incisors simultaneously subgingivally fractured due to dental trauma. Treatment involved flap surgery, reattachment and splinting of the fractured fragments with glass-fibre and composite resin. This reattachment technique, which uses advanced adhesive systems, is an option that offers satisfactory esthetic and functional outcomes.