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Aust Endod J 2014; 40: 17–20
ORIGINAL RESEARCH
Clinical comparison between the bleaching efficacy of light-emitting diode and diode laser with sodium perborate Sibel Koçak, PhD, DDS; Mustafa Murat Koçak, PhD, DDS; and Baran Can Sag˘lam, PhD, DDS Department of Endodontics, Faculty of Dentistry, Bülent Ecevit University, Zonguldak, Turkey
Keywords diode laser, intracoronal bleaching, light-emitting diode, sodium perborate. Correspondence Dr Mustafa Murat Koçak, Department of Endodontics, Faculty of Dentistry, Bülent Ecevit University, 67600, Zonguldak, Turkey. Email: [email protected] doi:10.1111/aej.12015
Abstract The aim of this clinical study was to test the efficacy of a light-emitting diode (LED) light and a diode laser, when bleaching with sodium perborate. Thirty volunteers were selected to participate in the study. The patients were randomly divided into two groups. The initial colour of each tooth to be bleached was quantified with a spectrophotometer. In group A, sodium perborate and distilled water were mixed and placed into the pulp chamber, and the LED light was source applied. In group B, the same mixture was used, and the 810 nm diode laser was applied. The final colour of each tooth was quantified with the same spectrophotometer. Initial and final spectrophotometer values were recorded. Mann–Whitney U-test and Wicoxon tests were used to test differences between both groups. Both devices successfully whitened the teeth. No statistical difference was found between the efficacy of the LED light and the diode laser.
Introduction Currently, more and more patients attend dental clinics to have their teeth whitened. Dentists and patients continually seek better techniques and treatments in this field of dental aesthetics. The contamination of the pulp cavity, irrigants, root canal and other restorative materials and pulpal injury may cause the discolouration of endodontically treated teeth (1,2). In discoloured non-vital teeth, the intracoronal bleaching procedure is widely used because it is efficient, relatively simple and low cost, and because it preserves the dental hard tissue better than prosthetic treatment (3). In the past, many techniques have been used for dental bleaching, especially for non-vital teeth, but the majority of them rely on an oxidation reaction in order to reverse the chromatic alteration of the dental tissues (4). Hydrogen peroxide, sodium perborate and carbamide peroxide are widely used as intracoronal bleaching agents for the treatment of discoloured teeth. Both hydrogen peroxide and sodium perborate, which also contains a small amount of hydrogen peroxide, remove the colour in stained dentine by oxidation. Hydrogen peroxide in concentrations of 30–35% has been shown to be caustic and may cause external cervical resorption, especially when the thermocatalytic technique is used (5).
© 2013 The Authors Australian Endodontic Journal © 2013 Australian Society of Endodontology
Sodium perborate is an oxidising agent available as a powder. It is stable when dry. However, in the presence of acid, warm air or water, it breaks down to form sodium metaborate, hydrogen peroxide and nascent oxygen (6). Sodium perborate occurs in the form of mono-, tri- or tetrahydrate (NaBO2 • H2O2 • 3H2O). Upon adding water, H2O2 is released. The bleaching effect is not weakened if sodium perborate is mixed with water instead of hydrogen peroxide (3). Rotstein et al. (7) reported that a mixture of sodium perborate and distilled water was effective as an intracoronal bleaching agent, and this paste has been recommended to decrease the risk of external resorption (8). Sodium perborate is easier to control and safer than concentrated hydrogen peroxide solutions (6). In order to provide faster and more effective treatment, bleaching agents have been used in association with an energy source with the goal of accelerating whitening gel’s oxi-reduction reaction (9). For many years, heat or light has been used to speed the breakdown of hydrogen peroxide, resulting in faster whitening. Many devices, such as halogen curing lights, light-emitting diodes (LEDs), diode lasers, argon lasers and plasma arc lamps have been used (10,11). However, lasers have recently become popular as an energy source during intracoronal bleaching. Alternatively, LEDs are relatively low cost, and 17
Bleaching Efficacy of LED and Laser
they require less energy to generate light (12). The efficacy of LEDs is also better than halogen lamps from light-curing units, and as a result, LEDs produce comparatively less heat (13). The aim of this clinical study was to evaluate the intracoronal bleaching ability of a sodium perborate and distilled water mixture when activated by either a LED light or a diode laser.
Materials and methods This study was performed under the regulations of the ethics committee of Bülent Ecevit University (protocol number: 2012-29-06/03). Patients referred to Department of Endodontics, Faculty of Dentistry, Bülent Ecevit University, were selected for this study. Thirty volunteers with a minimum shade of A3 were selected to participate in this single-blind (examiner-blinded), single-centre, two-group clinical study. Informed written consent in full accordance with ethical principles was obtained from each patient before treatment was initiated. Endodontically treated central incisors, lateral incisors or canines with colour changes were included. Selection was based on the patient’s request for treatment and an absence of gingival inflammation. Patients who had teeth with inadequate root canal treatment, signs of apical periodontitis with extensive restoration on the buccal surface, insufficient residual crown structure to guarantee successful application of the composite materials or enamel cracks were excluded. The initial colour of each tooth was measured with a spectrophotometer (VITA Easyshade Compact, VITA Zahnfabrik, Bad Säckingen, Germany) under standardised lighting conditions. After registering the initial colour, surrounding soft tissues were covered with Vaseline; discoloured teeth were placed under a rubber dam and tied with wax thread so that the sheet perfectly sealed the neck of the teeth, preventing the bleaching agent from reaching periodontal tissues. Standard access cavities were performed. During the preparation of access cavities, remnants of restorative materials, rootfilling materials and necrotic pulp tissue were completely removed. The cervical thirds of the canals were prepared with Gates-Glidden drills (Dentsply Maillefer, Ballaigues, Switzerland). Approximately 2 mm of Cavit (3M ESPE, Seefeld, Germany) was placed coronal to the gutta-percha in the canal, before the bleaching mixture was inserted into the pulp chamber. The patients were randomly divided into two groups (n = 15) as follows. For group A (with 11 central incisors and 4 lateral incisors), sodium perborate and distilled water were mixed to form a thick paste and placed into the pulp chamber. A LED light source (Elipar 18
S. Koçak et al.
S10, 3M ESPE) was applied for 30 s from the palatinal and 30 s from labial surfaces of the tooth with optical power 1200 mW cm-2 intensity. Group B (with 10 central incisors, 4 lateral incisors and 1 canine) received the same mixture as group A and an 810 nm diode laser (810 ⫾ 10 nm, AMD Picasso, Indianapolis, IN, USA) with standard handpiece and 400 mm fibre optic cable was applied for 30 s from the palatal and 30 s from the labial surfaces of the tooth. A power setting of 7 W was used. A continuous mode was chosen for the procedure. A cotton pellet was placed on the bleaching material to isolate it from the temporary filling. The access cavity was temporarily sealed with Cavit. Two days after the initial procedure was completed, the patients were recalled. The same procedures were applied at each recall appointment. Bleaching sessions were performed up to a maximum of three appointments to obtain acceptable results. After the last bleaching session, a calcium hydroxide paste was applied to pulp chambers for 7 days to neutralise the by-products of the bleaching agents. When acceptable results were obtained, the tooth was permanently restored by placing photo-activated composite resin (Filtek Ultimate, 3M ESPE, St Paul, MN, USA) in the pulp chamber. The final tooth colour was recorded with the same spectrophotometer used in the initial reading. All treatment procedures were performed by an endodontist with at least 5 years of experience. The tabs of the shade guide were arranged from B1 (the lightest colour) to C4 (the darkest colour), corresponding to a whitening scale graded from 1 to 16 in which a smaller number indicates a lighter shade of tooth enamel. Three measurements were made with the active point of the instrument focused on the middle third of each tooth. The spectrophotometer measures the colour of teeth based on the Commission Internationale de I’Eclairage’s CIELAB colour space system. The image of the tooth is automatically transformed to derive a set of numerical values in terms of the L* a* b* system. The L* a* b* system allows colour specification within threedimensional space. The L* axis represents the degree of lightness within a tooth and ranges from 0 (black) to 100 (white). The a* plane represents the degree of green– red, while the b* plane represents the degree of blue– yellow in the teeth being measured. DE is the total colour difference, or the distance between two colours. The difference between colour coordinates is calculated 2 2 2 12 as ΔE * = (( ΔL*) + ( Δa*) + ( Δb*) ) . Statistical analysis was performed with SPSS 18.0 software (SPSS, Inc., Chicago, IL, USA). Testing for violations of normality was checked by the Shapiro–Wilk W-test. The data set was normally distributed (P > 0.05). The difference between initial and final DE values were analysed by paired sample t test. Mann–Whitney U-test and
© 2013 The Authors Australian Endodontic Journal © 2013 Australian Society of Endodontology
Bleaching Efficacy of LED and Laser
S. Koçak et al.
Wicoxon tests were used to determine the differences between groups. P-values of less than 0.05 were considered statistically significant for all tests.
Results All 30 participants completed the study. Initial DE values ranged from grades 9.4 to 15.6, and final DE values ranged from grades 1.9 to 6.7 (Table 1). Both the LED and diodelaser energy sources proved to be effective at whitening, with a mean value of 8.67 ⫾ 1.885 for the LED group, and 8.74 ⫾ 1.847 for the diode-laser group. The mean initial and final DE values are shown in Table 2. The lower final mean DE value was obtained when the diode laser was used. However, the difference between the two devices was not found to be statistically significant (P > 0.05).
Discussion In this clinical study, the efficacy of the LED light source and the 810 nm diode laser used with a mixture of sodium perborate and distilled water on intracoronal bleaching was determined. Several in vitro and in vivo studies have already investigated the efficacy of devices including halogens, LEDs and lasers during intracoronal bleaching. All devices were used with various bleaching agents, including hydrogen peroxide, carbamide
Table 1 Initial and final DE values of patients LED
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Diode laser
Initial
Final
Initial
Final
14.7 10.1 9.4 10.8 14.2 12.1 12.7 13.7 15.0 13.4 10.3 10.4 12.3 13.2 14.8
6.7 5.3 4.2 3.9 4.1 4.6 3.9 3.1 3.5 3.2 2.2 3.8 3.3 2.4 1.9
10.8 11.7 14.6 12.5 13.7 14.1 15.6 11.4 10.3 9.8 10.3 14.4 10.7 12.8 13.6
3.2 2.6 2.5 2.2 4.1 3.2 2.9 4.1 2.5 2.7 2.1 2.6 3.3 2.5 4.7
Table 2 Mean initial and final DE values
LED Diode laser
n
Mean initial DE
Mean final DE
15 15
12.47 ⫾ 1.885 12.42 ⫾ 1.847
3.74 ⫾ 1.219 3.01 ⫾ 0.760
© 2013 The Authors Australian Endodontic Journal © 2013 Australian Society of Endodontology
peroxide and sodium perborate by themselves or in direct comparison with each other. However, neither in vitro nor in vivo results are truly representative of clinical situations where the whole treatment is done in the mouth. On the other hand, clinical studies, such as those mentioned previously, may provide a high level of evidence for clinical practice since they reflect a more strictly clinical condition. A root filling does not adequately prevent diffusion of bleaching agents from the pulpal chamber to the apical foramen (14). A base is required to prevent radicular penetration of bleaching agents (15). Therefore, sealing the root filling with a base is essential. A variety of dental materials have been suggested for use as an interim sealing agent during bleaching techniques (6). Cavit-G was used as the intracoronal barrier to minimise the risk of root resorption. Hydrogen peroxide is very effective at bleaching teeth, but Barkhordar et al. (16) and Friedman (17) reported that using hydrogen peroxide was related to an increase in cervical resorption. Holmstrup et al. (18) did not detect external cervical resorption in pulpless teeth after intracoronal bleaching with a mixture of sodium perborate and water after an evaluation of 3 years. Sodium perborate demonstrated satisfactory results in clinical tests of dental bleaching (3,18). Ari and Üngör (3) verified that no statistically significant difference in aesthetic results was found when all three types of sodium perborate were used with water or when using 30% hydrogen peroxide in the intracoronal bleaching of pulpless teeth. Ari and Üngör (3) also reported that sodium perborate should be mixed with water rather than with hydrogen peroxide in order to prevent or minimise the occurrence of bleachingrelated external root resorption. To accelerate the oxidation reaction and increase the efficacy of sodium perborate, various sources of irradiation can be used. In this study, sodium perborate and water presented satisfactory aesthetic results. These results are in agreement with several previous studies that demonstrated that the sodium perborate with water is an effective bleaching agent. The biocompatibility of the bleaching agent is more important than the efficiency and rapidity of its results. Instead of using products with cytotoxic potential, biocompatible substitutes must be the first choice, despite being more time-consuming in intracoronal bleaching procedures (17). Heat or light sources have been used to speed up the breakdown of bleaching material for a faster whitening result (9). Previous studies reported that activation of bleaching agents with light sources showed significantly better results than when the same agent was used alone (9,10,19). Therefore, the efficacy of sources must be well considered. The different lasers used in dentistry 19
Bleaching Efficacy of LED and Laser
approved by the U.S. Food and Drug Administration are diode, erbium, CO2, argon and neodymium-doped yttrium aluminum garnet (Nd:YAG). At present, diode, erbium, CO2 and (Nd:YAG) are the most commonly used lasers in dentistry. Dental laser use in tooth bleaching appears to be increasing. Dostalova et al. (20) reported that the laser is the most valuable energy source for power bleaching even with simple and short applications. The diode laser employs a solid-state semiconductor that uses a combination of aluminum, gallium and arsenide to change electric energy into light energy. Wave lengths range from 800 to 980 nm. The main advantage of the diode laser is that it can be packaged in a relatively small size instrument. In the present study, an 810 nm diode laser was used. Previously, Dantas et al. (21) reported that the phototherapy with a low-intensity laser compensated for the cytotoxic effects of substances released by bleaching gel. When using a 980 nm diode laser at 0.8 W, the resulting temperature rise recorded was higher than when an LED was used (22). To the author’s knowledge, no literature has been published concerning the efficacy of an 810 nm diode laser for the bleaching of discoloured, endodontically treated teeth. When the initial and final DE values were compared, both LED and diode laser devices were found statistically and clinically efficient in the intracoronal bleaching of non-vital teeth. Specifically, the results revealed that the 810 nm diode laser used in this study was effective for the whitening of discoloured teeth. Moreover, the compact size of the device provides another significant advantage in clinical practice.
Conclusion Both the LED light source and the diode laser similarly and successfully bleached discoloured endodontically treated teeth with a mixture of sodium perborate and distilled water used as a bleaching agent.
References 1. Zimmerli B, Jeger F, Lussi A. Bleaching of nonvital teeth. A clinically relevant literature review. Schweiz Monatsschr Zahnmed 2010; 120: 306–20. 2. Attin T, Paqué F, Ajam F, Lennon ÁM. Review of the current status of tooth whitening with the walking bleach technique. Int Endod J 2003; 36: 313–29. 3. Ari H, Üngör M. In vitro comparison of different types of sodium perborate used for intracoronal bleaching of discoloured teeth. Int Endod J 2002; 35: 433–6. 4. Smigel I. Laser tooth whitening. Dent Today 1996; 15: 32–6. 5. Harrington GN, Natkin E. External resorption associated with bleaching of pulpless teeth. J Endod 1979; 5: 344–8.
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6. Plotino G, Buono L, Grande NM, Pameijer CH, Somma F. Nonvital tooth bleaching: a review of the literature and clinical procedures. J Endod 2008; 34: 394–407. 7. Rotstein I, Mor C, Friedman S. Prognosis of intracoronal bleaching with sodium perborate preparation in vitro: 1-year study. J Endod 1993; 19: 10–12. 8. Rotstein I, Zalkind M, Mor C, Tarabeah A, Friedman S. In vitro efficiency of sodium perborate preparations used for intracoronal bleaching of nonvital teeth. Endod Dent Traumatol 1991; 7: 177–88. 9. Lima DA, Aguiar FH, Liporoni PC, Munin E, Ambrosano GM, Lovadino JR. In vitro evaluation of the effectiveness of bleaching agents activated by different light sources. J Prosthodont 2009; 18: 249–54. 10. Luk K, Tam L, Hubert M. Effect of light energy on peroxide tooth bleaching. J Am Dent Assoc 2004; 135: 194– 201. 11. Buchalla W, Attin T. External bleaching therapy with activation by heat, light or laser – A systematic review. Dent Mater 2007; 23: 586–96. 12. Kurachi C, Tuboy AM, Magalhães DV, Bagnato VS. Hardness evaluation of a dental composite polimerized with experimental LED-based devices. Dent Mater 2001; 17: 309–15. 13. Yap AU, Soh MS. Thermal emission by different lightcuring units. Oper Dent 2003; 28: 260–6. 14. Smith JJ, Cunningham CJ, Montgomery S. Cervical canal leakage after internal bleaching procedures. J Endod 1992; 18: 476–81. 15. Hansen-Bayless J, Davis R. Sealing ability of two intermediate restorative materials in bleached teeth. Am J Dent 1992; 5: 151–4. 16. Barkhordar RA, Kempler D, Plesh O. Effect of nonvital tooth bleaching on microleakage of resin composite restorations. Quintessence Int 1997; 28: 341–4. 17. Friedman S. Internal bleaching: long-term outcomes and complications. J Am Dent Assoc 1997; 128: 51s–55. 18. Holmstrup G, Palm AM, Lambjerg-Hansen H. Bleaching of discolored root-filled teeth. Endod Dent Traumatol 1988; 4: 197–201. 19. Wetter NU, Barroso MC, Pelino JE. Dental bleaching efficacy with diode laser and LED irradiation: an in vitro study. Lasers Surg Med 2004; 35: 254–8. 20. Dostalova T, Jelinkova H, Housova D et al. Diode laser-activated bleaching. Braz Dent J 2004; 15: SI3–8. 21. Dantas CM, Vivan CL, Ferreira LS, Freitas PM, Marques MM. In vitro effect of low intensity laser on the cytotoxicity produced by substances released by bleaching gel. Braz Oral Res 2010; 24: 460–6. 22. Zhang C, Wang X, Kinoshita J et al. Effects of KTP laser irradiation, diode laser, and LED on tooth bleaching: a comparative study. Photomed Laser Surg 2007; 25: 91–5.
© 2013 The Authors Australian Endodontic Journal © 2013 Australian Society of Endodontology
Aust Endod J 2014; 40: 17–20
ORIGINAL RESEARCH
Clinical comparison between the bleaching efficacy of light-emitting diode and diode laser with sodium perborate Sibel Koçak, PhD, DDS; Mustafa Murat Koçak, PhD, DDS; and Baran Can Sag˘lam, PhD, DDS Department of Endodontics, Faculty of Dentistry, Bülent Ecevit University, Zonguldak, Turkey
Keywords diode laser, intracoronal bleaching, light-emitting diode, sodium perborate. Correspondence Dr Mustafa Murat Koçak, Department of Endodontics, Faculty of Dentistry, Bülent Ecevit University, 67600, Zonguldak, Turkey. Email: [email protected] doi:10.1111/aej.12015
Abstract The aim of this clinical study was to test the efficacy of a light-emitting diode (LED) light and a diode laser, when bleaching with sodium perborate. Thirty volunteers were selected to participate in the study. The patients were randomly divided into two groups. The initial colour of each tooth to be bleached was quantified with a spectrophotometer. In group A, sodium perborate and distilled water were mixed and placed into the pulp chamber, and the LED light was source applied. In group B, the same mixture was used, and the 810 nm diode laser was applied. The final colour of each tooth was quantified with the same spectrophotometer. Initial and final spectrophotometer values were recorded. Mann–Whitney U-test and Wicoxon tests were used to test differences between both groups. Both devices successfully whitened the teeth. No statistical difference was found between the efficacy of the LED light and the diode laser.
Introduction Currently, more and more patients attend dental clinics to have their teeth whitened. Dentists and patients continually seek better techniques and treatments in this field of dental aesthetics. The contamination of the pulp cavity, irrigants, root canal and other restorative materials and pulpal injury may cause the discolouration of endodontically treated teeth (1,2). In discoloured non-vital teeth, the intracoronal bleaching procedure is widely used because it is efficient, relatively simple and low cost, and because it preserves the dental hard tissue better than prosthetic treatment (3). In the past, many techniques have been used for dental bleaching, especially for non-vital teeth, but the majority of them rely on an oxidation reaction in order to reverse the chromatic alteration of the dental tissues (4). Hydrogen peroxide, sodium perborate and carbamide peroxide are widely used as intracoronal bleaching agents for the treatment of discoloured teeth. Both hydrogen peroxide and sodium perborate, which also contains a small amount of hydrogen peroxide, remove the colour in stained dentine by oxidation. Hydrogen peroxide in concentrations of 30–35% has been shown to be caustic and may cause external cervical resorption, especially when the thermocatalytic technique is used (5).
© 2013 The Authors Australian Endodontic Journal © 2013 Australian Society of Endodontology
Sodium perborate is an oxidising agent available as a powder. It is stable when dry. However, in the presence of acid, warm air or water, it breaks down to form sodium metaborate, hydrogen peroxide and nascent oxygen (6). Sodium perborate occurs in the form of mono-, tri- or tetrahydrate (NaBO2 • H2O2 • 3H2O). Upon adding water, H2O2 is released. The bleaching effect is not weakened if sodium perborate is mixed with water instead of hydrogen peroxide (3). Rotstein et al. (7) reported that a mixture of sodium perborate and distilled water was effective as an intracoronal bleaching agent, and this paste has been recommended to decrease the risk of external resorption (8). Sodium perborate is easier to control and safer than concentrated hydrogen peroxide solutions (6). In order to provide faster and more effective treatment, bleaching agents have been used in association with an energy source with the goal of accelerating whitening gel’s oxi-reduction reaction (9). For many years, heat or light has been used to speed the breakdown of hydrogen peroxide, resulting in faster whitening. Many devices, such as halogen curing lights, light-emitting diodes (LEDs), diode lasers, argon lasers and plasma arc lamps have been used (10,11). However, lasers have recently become popular as an energy source during intracoronal bleaching. Alternatively, LEDs are relatively low cost, and 17
Bleaching Efficacy of LED and Laser
they require less energy to generate light (12). The efficacy of LEDs is also better than halogen lamps from light-curing units, and as a result, LEDs produce comparatively less heat (13). The aim of this clinical study was to evaluate the intracoronal bleaching ability of a sodium perborate and distilled water mixture when activated by either a LED light or a diode laser.
Materials and methods This study was performed under the regulations of the ethics committee of Bülent Ecevit University (protocol number: 2012-29-06/03). Patients referred to Department of Endodontics, Faculty of Dentistry, Bülent Ecevit University, were selected for this study. Thirty volunteers with a minimum shade of A3 were selected to participate in this single-blind (examiner-blinded), single-centre, two-group clinical study. Informed written consent in full accordance with ethical principles was obtained from each patient before treatment was initiated. Endodontically treated central incisors, lateral incisors or canines with colour changes were included. Selection was based on the patient’s request for treatment and an absence of gingival inflammation. Patients who had teeth with inadequate root canal treatment, signs of apical periodontitis with extensive restoration on the buccal surface, insufficient residual crown structure to guarantee successful application of the composite materials or enamel cracks were excluded. The initial colour of each tooth was measured with a spectrophotometer (VITA Easyshade Compact, VITA Zahnfabrik, Bad Säckingen, Germany) under standardised lighting conditions. After registering the initial colour, surrounding soft tissues were covered with Vaseline; discoloured teeth were placed under a rubber dam and tied with wax thread so that the sheet perfectly sealed the neck of the teeth, preventing the bleaching agent from reaching periodontal tissues. Standard access cavities were performed. During the preparation of access cavities, remnants of restorative materials, rootfilling materials and necrotic pulp tissue were completely removed. The cervical thirds of the canals were prepared with Gates-Glidden drills (Dentsply Maillefer, Ballaigues, Switzerland). Approximately 2 mm of Cavit (3M ESPE, Seefeld, Germany) was placed coronal to the gutta-percha in the canal, before the bleaching mixture was inserted into the pulp chamber. The patients were randomly divided into two groups (n = 15) as follows. For group A (with 11 central incisors and 4 lateral incisors), sodium perborate and distilled water were mixed to form a thick paste and placed into the pulp chamber. A LED light source (Elipar 18
S. Koçak et al.
S10, 3M ESPE) was applied for 30 s from the palatinal and 30 s from labial surfaces of the tooth with optical power 1200 mW cm-2 intensity. Group B (with 10 central incisors, 4 lateral incisors and 1 canine) received the same mixture as group A and an 810 nm diode laser (810 ⫾ 10 nm, AMD Picasso, Indianapolis, IN, USA) with standard handpiece and 400 mm fibre optic cable was applied for 30 s from the palatal and 30 s from the labial surfaces of the tooth. A power setting of 7 W was used. A continuous mode was chosen for the procedure. A cotton pellet was placed on the bleaching material to isolate it from the temporary filling. The access cavity was temporarily sealed with Cavit. Two days after the initial procedure was completed, the patients were recalled. The same procedures were applied at each recall appointment. Bleaching sessions were performed up to a maximum of three appointments to obtain acceptable results. After the last bleaching session, a calcium hydroxide paste was applied to pulp chambers for 7 days to neutralise the by-products of the bleaching agents. When acceptable results were obtained, the tooth was permanently restored by placing photo-activated composite resin (Filtek Ultimate, 3M ESPE, St Paul, MN, USA) in the pulp chamber. The final tooth colour was recorded with the same spectrophotometer used in the initial reading. All treatment procedures were performed by an endodontist with at least 5 years of experience. The tabs of the shade guide were arranged from B1 (the lightest colour) to C4 (the darkest colour), corresponding to a whitening scale graded from 1 to 16 in which a smaller number indicates a lighter shade of tooth enamel. Three measurements were made with the active point of the instrument focused on the middle third of each tooth. The spectrophotometer measures the colour of teeth based on the Commission Internationale de I’Eclairage’s CIELAB colour space system. The image of the tooth is automatically transformed to derive a set of numerical values in terms of the L* a* b* system. The L* a* b* system allows colour specification within threedimensional space. The L* axis represents the degree of lightness within a tooth and ranges from 0 (black) to 100 (white). The a* plane represents the degree of green– red, while the b* plane represents the degree of blue– yellow in the teeth being measured. DE is the total colour difference, or the distance between two colours. The difference between colour coordinates is calculated 2 2 2 12 as ΔE * = (( ΔL*) + ( Δa*) + ( Δb*) ) . Statistical analysis was performed with SPSS 18.0 software (SPSS, Inc., Chicago, IL, USA). Testing for violations of normality was checked by the Shapiro–Wilk W-test. The data set was normally distributed (P > 0.05). The difference between initial and final DE values were analysed by paired sample t test. Mann–Whitney U-test and
© 2013 The Authors Australian Endodontic Journal © 2013 Australian Society of Endodontology
Bleaching Efficacy of LED and Laser
S. Koçak et al.
Wicoxon tests were used to determine the differences between groups. P-values of less than 0.05 were considered statistically significant for all tests.
Results All 30 participants completed the study. Initial DE values ranged from grades 9.4 to 15.6, and final DE values ranged from grades 1.9 to 6.7 (Table 1). Both the LED and diodelaser energy sources proved to be effective at whitening, with a mean value of 8.67 ⫾ 1.885 for the LED group, and 8.74 ⫾ 1.847 for the diode-laser group. The mean initial and final DE values are shown in Table 2. The lower final mean DE value was obtained when the diode laser was used. However, the difference between the two devices was not found to be statistically significant (P > 0.05).
Discussion In this clinical study, the efficacy of the LED light source and the 810 nm diode laser used with a mixture of sodium perborate and distilled water on intracoronal bleaching was determined. Several in vitro and in vivo studies have already investigated the efficacy of devices including halogens, LEDs and lasers during intracoronal bleaching. All devices were used with various bleaching agents, including hydrogen peroxide, carbamide
Table 1 Initial and final DE values of patients LED
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Diode laser
Initial
Final
Initial
Final
14.7 10.1 9.4 10.8 14.2 12.1 12.7 13.7 15.0 13.4 10.3 10.4 12.3 13.2 14.8
6.7 5.3 4.2 3.9 4.1 4.6 3.9 3.1 3.5 3.2 2.2 3.8 3.3 2.4 1.9
10.8 11.7 14.6 12.5 13.7 14.1 15.6 11.4 10.3 9.8 10.3 14.4 10.7 12.8 13.6
3.2 2.6 2.5 2.2 4.1 3.2 2.9 4.1 2.5 2.7 2.1 2.6 3.3 2.5 4.7
Table 2 Mean initial and final DE values
LED Diode laser
n
Mean initial DE
Mean final DE
15 15
12.47 ⫾ 1.885 12.42 ⫾ 1.847
3.74 ⫾ 1.219 3.01 ⫾ 0.760
© 2013 The Authors Australian Endodontic Journal © 2013 Australian Society of Endodontology
peroxide and sodium perborate by themselves or in direct comparison with each other. However, neither in vitro nor in vivo results are truly representative of clinical situations where the whole treatment is done in the mouth. On the other hand, clinical studies, such as those mentioned previously, may provide a high level of evidence for clinical practice since they reflect a more strictly clinical condition. A root filling does not adequately prevent diffusion of bleaching agents from the pulpal chamber to the apical foramen (14). A base is required to prevent radicular penetration of bleaching agents (15). Therefore, sealing the root filling with a base is essential. A variety of dental materials have been suggested for use as an interim sealing agent during bleaching techniques (6). Cavit-G was used as the intracoronal barrier to minimise the risk of root resorption. Hydrogen peroxide is very effective at bleaching teeth, but Barkhordar et al. (16) and Friedman (17) reported that using hydrogen peroxide was related to an increase in cervical resorption. Holmstrup et al. (18) did not detect external cervical resorption in pulpless teeth after intracoronal bleaching with a mixture of sodium perborate and water after an evaluation of 3 years. Sodium perborate demonstrated satisfactory results in clinical tests of dental bleaching (3,18). Ari and Üngör (3) verified that no statistically significant difference in aesthetic results was found when all three types of sodium perborate were used with water or when using 30% hydrogen peroxide in the intracoronal bleaching of pulpless teeth. Ari and Üngör (3) also reported that sodium perborate should be mixed with water rather than with hydrogen peroxide in order to prevent or minimise the occurrence of bleachingrelated external root resorption. To accelerate the oxidation reaction and increase the efficacy of sodium perborate, various sources of irradiation can be used. In this study, sodium perborate and water presented satisfactory aesthetic results. These results are in agreement with several previous studies that demonstrated that the sodium perborate with water is an effective bleaching agent. The biocompatibility of the bleaching agent is more important than the efficiency and rapidity of its results. Instead of using products with cytotoxic potential, biocompatible substitutes must be the first choice, despite being more time-consuming in intracoronal bleaching procedures (17). Heat or light sources have been used to speed up the breakdown of bleaching material for a faster whitening result (9). Previous studies reported that activation of bleaching agents with light sources showed significantly better results than when the same agent was used alone (9,10,19). Therefore, the efficacy of sources must be well considered. The different lasers used in dentistry 19
Bleaching Efficacy of LED and Laser
approved by the U.S. Food and Drug Administration are diode, erbium, CO2, argon and neodymium-doped yttrium aluminum garnet (Nd:YAG). At present, diode, erbium, CO2 and (Nd:YAG) are the most commonly used lasers in dentistry. Dental laser use in tooth bleaching appears to be increasing. Dostalova et al. (20) reported that the laser is the most valuable energy source for power bleaching even with simple and short applications. The diode laser employs a solid-state semiconductor that uses a combination of aluminum, gallium and arsenide to change electric energy into light energy. Wave lengths range from 800 to 980 nm. The main advantage of the diode laser is that it can be packaged in a relatively small size instrument. In the present study, an 810 nm diode laser was used. Previously, Dantas et al. (21) reported that the phototherapy with a low-intensity laser compensated for the cytotoxic effects of substances released by bleaching gel. When using a 980 nm diode laser at 0.8 W, the resulting temperature rise recorded was higher than when an LED was used (22). To the author’s knowledge, no literature has been published concerning the efficacy of an 810 nm diode laser for the bleaching of discoloured, endodontically treated teeth. When the initial and final DE values were compared, both LED and diode laser devices were found statistically and clinically efficient in the intracoronal bleaching of non-vital teeth. Specifically, the results revealed that the 810 nm diode laser used in this study was effective for the whitening of discoloured teeth. Moreover, the compact size of the device provides another significant advantage in clinical practice.
Conclusion Both the LED light source and the diode laser similarly and successfully bleached discoloured endodontically treated teeth with a mixture of sodium perborate and distilled water used as a bleaching agent.
References 1. Zimmerli B, Jeger F, Lussi A. Bleaching of nonvital teeth. A clinically relevant literature review. Schweiz Monatsschr Zahnmed 2010; 120: 306–20. 2. Attin T, Paqué F, Ajam F, Lennon ÁM. Review of the current status of tooth whitening with the walking bleach technique. Int Endod J 2003; 36: 313–29. 3. Ari H, Üngör M. In vitro comparison of different types of sodium perborate used for intracoronal bleaching of discoloured teeth. Int Endod J 2002; 35: 433–6. 4. Smigel I. Laser tooth whitening. Dent Today 1996; 15: 32–6. 5. Harrington GN, Natkin E. External resorption associated with bleaching of pulpless teeth. J Endod 1979; 5: 344–8.
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S. Koçak et al.
6. Plotino G, Buono L, Grande NM, Pameijer CH, Somma F. Nonvital tooth bleaching: a review of the literature and clinical procedures. J Endod 2008; 34: 394–407. 7. Rotstein I, Mor C, Friedman S. Prognosis of intracoronal bleaching with sodium perborate preparation in vitro: 1-year study. J Endod 1993; 19: 10–12. 8. Rotstein I, Zalkind M, Mor C, Tarabeah A, Friedman S. In vitro efficiency of sodium perborate preparations used for intracoronal bleaching of nonvital teeth. Endod Dent Traumatol 1991; 7: 177–88. 9. Lima DA, Aguiar FH, Liporoni PC, Munin E, Ambrosano GM, Lovadino JR. In vitro evaluation of the effectiveness of bleaching agents activated by different light sources. J Prosthodont 2009; 18: 249–54. 10. Luk K, Tam L, Hubert M. Effect of light energy on peroxide tooth bleaching. J Am Dent Assoc 2004; 135: 194– 201. 11. Buchalla W, Attin T. External bleaching therapy with activation by heat, light or laser – A systematic review. Dent Mater 2007; 23: 586–96. 12. Kurachi C, Tuboy AM, Magalhães DV, Bagnato VS. Hardness evaluation of a dental composite polimerized with experimental LED-based devices. Dent Mater 2001; 17: 309–15. 13. Yap AU, Soh MS. Thermal emission by different lightcuring units. Oper Dent 2003; 28: 260–6. 14. Smith JJ, Cunningham CJ, Montgomery S. Cervical canal leakage after internal bleaching procedures. J Endod 1992; 18: 476–81. 15. Hansen-Bayless J, Davis R. Sealing ability of two intermediate restorative materials in bleached teeth. Am J Dent 1992; 5: 151–4. 16. Barkhordar RA, Kempler D, Plesh O. Effect of nonvital tooth bleaching on microleakage of resin composite restorations. Quintessence Int 1997; 28: 341–4. 17. Friedman S. Internal bleaching: long-term outcomes and complications. J Am Dent Assoc 1997; 128: 51s–55. 18. Holmstrup G, Palm AM, Lambjerg-Hansen H. Bleaching of discolored root-filled teeth. Endod Dent Traumatol 1988; 4: 197–201. 19. Wetter NU, Barroso MC, Pelino JE. Dental bleaching efficacy with diode laser and LED irradiation: an in vitro study. Lasers Surg Med 2004; 35: 254–8. 20. Dostalova T, Jelinkova H, Housova D et al. Diode laser-activated bleaching. Braz Dent J 2004; 15: SI3–8. 21. Dantas CM, Vivan CL, Ferreira LS, Freitas PM, Marques MM. In vitro effect of low intensity laser on the cytotoxicity produced by substances released by bleaching gel. Braz Oral Res 2010; 24: 460–6. 22. Zhang C, Wang X, Kinoshita J et al. Effects of KTP laser irradiation, diode laser, and LED on tooth bleaching: a comparative study. Photomed Laser Surg 2007; 25: 91–5.
© 2013 The Authors Australian Endodontic Journal © 2013 Australian Society of Endodontology
