Application of the Remineralizing Therapy During At-Home Vital Teeth Whitening

Transcription

1 Application of the Remineralizing Therapy During At-Home Vital Teeth Whitening Zheleznyy P.A., M.D., professor Bazin А.К., Candidate of Medical Science, associate professor Zheleznaya Y.K., Candidate of Medical Science, associate professor Rusakova E.Y., Candidate of Medical Science, associate professor Zheleznaya А.P., Perminov А.S., Shashkova О.V. Childhood dentistry department of the Novosibirsk state medical university, Regional dentists association of Novosibirsk Matelo S.K. Group of Companies DRC, Moscow INTRODUCTION In the course of the last decade one can observe an increase in the aesthetic requirements of patients caused by various reasons including the impact of foreign mass media promoting natural beauty of healthy teeth [1, 2]. The idea of tooth whitening attracts many patients. When they come to a dentist s room for medical advice regarding this procedure, in most cases they question about safety. [3, 8, 16]. Quite often dentists do not possess information that could be considered sufficiently objective because Russia as well as other countries of the whole globe feel the deficiency of scientific data about influence of the bleaching systems upon human teeth. In the year of 2006 H. Hasson and his co-auth. published an analytical survey of clinical investigations of the dental bleaching procedure carried out at the home place. Having analyzed 416 articles devoted to teeth whitening, it was found out that just 25 works included data, which could be analyzed by using statistical methods. The inclusion criteria had been met only in these 25 cases as well. All analyzed works included information about the dental whitening results, which were received immediately after this procedure completion, while data obtained 1-2 weeks later after the investigation of the medical course had been finished, were given just in 13 papers. The follow-up results (1 month later and more) of the investigation were registered just in 6 works. It is significant that all the researches had been sponsored by the dental bleaching system manufacturers. The authors of the analytical survey drew a conclusion that information about the influence of whitening methods upon the oral cavity organs was fragmentary and chaotic and there was a strong necessity to conduct

2 independent clinical researches that would include the assessment of the stability of the aesthetic treatment results and long-term consequences [14]. Enamel hyperesthesia (14 78% of the cases) and irritation of soft tissues (that is why it is recommended to thoroughly isolate gums from contact with the peroxide gel) are the most wide-spread side effects [24]. Tooth hyperesthesia can be a result of the demineralization of the dental hard tissues. The demineralization effect can be caused not only by peroxidates but also by the components of the base. This point of view can be confirmed by information provided by Jorgensen M.G., Carroll W.B. According to their data almost 30% of the patients, who were using the placebo gel, noticed light forms of hyperesthesia after 3 weeks of use [15]. It is wellknown that in the majority of cases of at-home teeth whitening the increased dental sensitivity is caused by the carbopol polymer based whitening systems, which are more viscous in contrast to preparations that are less viscous [23]. There are evidences proving that protracted applications of carbopol can also result in the enamel demineralization [20]. The data proving the facts of demineralization of tooth hard tissues during the whitening procedure are not of rare occurrence nowadays [9, 12, 17, 22, 11, 13]. As the methods of investigations are being constantly improved they helped obtain evidences regarding morphological changes in the surface layer of the enamel. For instance, enamel porosity starts developing, which is a result of the disappearance of the aprismatic mineral layer [17, 25]. Using the method of microtomography, the registered depth of the enamel demineralization area is equal to 50 micrometers [12]. Moreover, in recent years a whole array of works has been published that describe changes in the mechanical qualities of the demineralized tissues. As a result of dental whitening procedure, in such demineralized tissues one can observe a significant decrease in their microhardness [9, 17, 20], in the strength (Young s Modulus) of the nontubular dentin and enamel [9], values of the filling material adhesion [21] and in other indicators that characterize the biomechanical status of teeth. We are uncertain about the viewpoint, according to which there is no increased risk of the development/progression of erosions and dental caries [19, 7], especially if to take into consideration the fact that authors make their conclusions upon the basis of in vitro investigations. Virtually no literature work contains information that would describe the dynamics of biochemical characteristics of saliva during the teeth bleaching procedure [3, 5, 18]. In spite of the high prevalence of this method, up till now many Russian specialists still regard dental bleaching as a procedure that damages teeth rather significantly. Analogous fears are expressed by western specialists referring to cases from their clinical practice [10, 12]. On the other hand, the question of follow-up results of such exposure has not been studied properly yet. The problem of the increased risk of the formation of caries and other pathologies of tooth hard tissues still remains unclear and requires more accurate information [14].

3 MATERIALS AND METHODS Among the patients complaining about the change in their teeth colour 78 people aged from 25 to 35 years old with indications for at-home whitening of vital teeth located in front sections of the lower and upper jaws were selected. Prior to the whitening procedure all the patients had a satisfactory hygienic state of their oral cavities (OHI-S did not exceed 1,6), a healthy periodontium or a light degree of inflammation of the gingival margin. The dental caries intensity was assessed using the DMF index (decayed, missing, filled teeth). All patients had an average level of dental caries intensity. Oral cavity sanation and professional hygienic treatment were fulfilled prior to the teeth bleaching procedure. Personal hygienic care, diet and habits were corrected before dental whitening as well. All patients gave their written consent for their teeth to be bleached. Before the whitening procedure the initial tooth colour was determined in all the patients by using the standard Vita scale (table 1). Table 1. METHOD OF TOOTH COLOUR CHANGES ASSESSMENT WITH VITA SCALE ORDER OF SHADES FROM LIGHT TO DARK Shade on the scale B1 A1 C1 B2 A2 D2 A3 D3 B3 D4 C2 C3 B4 C4 A3.5 A Assigned number Patients were divided into 3 equivalent groups. Treatment was carried out in conformity with the schemes given in table 2. Table 2. IMPLEMENTATED SCHEMES OF DENTAL BLEACHING Group 1 (28 people) 2 (27 people) 3 (23 people) Correction of hygienic habits Professional hygienic treatment and sanation Whitening yes yes At home during 1 month. Applications: once a day for 20 min. yes yes At home during 1 month. Applications: once a day for 20 min. yes yes At home during 1 month. Applications: once a day for 20 min. Remineralizing therapy No At home, after the whitening procedures, once a day for 20 min. In ambulatory conditions. Every other day. Applications of 5% calcium glycerophosphate solution for 10 minutes. 3 minutes oral rinsing with 0,2 % NaF solution.

4 Tooth whitening was carried out by at-home method using an individual mouth-piece together with commercial samples of the gel containing 10% of carbamide peroxide. The dental bleaching course lasted for one month. Applications of peroxide gel were made daily, one time a day for 20 minutes. Remineralizing therapy was carried out using two schemes. In group 2 a commercial composition, R.O.C.S. Medical Minerals gel was used. The patients were given this remineralizing gel to be used at home as 20 minutes applications immediately after the whitening gel has been used. Patients from group 3 followed a standard methodology of the remineralizing therapy, which implied the use of the 5% calcium glycerophosphate solution applications in the course of 10 minutes and oral rinsing (mouth bath) with 0,2% sodium fluoride solution in the course of 3 minutes. The remineralizing procedures were started one day later after the whitening course had begun and were carried out every other day in the course of one month (all in all, 14 remineralizing procedures were made). Hyperesthesia prevalence in the groups of patients was determined in the percent correlation and its presence or absence was taken as a basis. Classification by Fedorov Yu.A. [6] was used for diagnosing the hyperesthesia of the tooth hard tissues. According to this classification in case of the first degree of severity the teeth react to temperature irritants (cold, hot); in case of the second degree of severity they react to chemical irritants (sweet, sour) while in case of the third degree they react to all irritant types (temperature, chemical and tactile). Then, the following characteristics were under control in the course of one year: 1. Tooth colour 2. Hyperesthesia presence 3. Dental caries intensity according to DMF index (decayed, missing, filled teeth) 4. Calcium content in the oral cavity fluid The received results of the clinical investigations underwent the statistical treatment with the determination of the average arithmetical value (М), the average quadratic deviation (у), the average quadratic mistake (m) and the validation criterion (t). Taking this criterion as a basis the reliability of the studied characteristic (P) was determined using the Student s table. The differences were considered to be trustworthy in case of p<0,05.

5 RESULTS AND DISCUSSION Efficacy of the aesthetic treatment The scheme of the peroxide gel use was in conformance with the manufacturer s recommendations and made it possible to improve the tooth colour. On the average, the tooth colour improvement equaled 2,09 points of Vita scale. Better results were registered in the groups, in which at-home bleaching methods and remineralizing therapy were combined. The results in group 2 and group 3 amounted to 3,45 and 3,41 points, respectively. In average, the combination of methods of dental whitening with the peroxide gel and remineralizing therapy with calcium and phosphorus salts ensured 65% rise in the aesthetical treatment effectiveness (pic. 1). Unstable achieved results are one of the most serious problems arising after the aesthetical treatment by using the dental whitening method. Continuance of the aesthetical results is dependent upon the hygienic regime, dietary preferences and harmful habits. In our investigation the monitoring of the groups was fulfilled in the course of one year and this characteristic was assessed three months and one year later after the dental bleaching course had been finished. In group 1 the average values of the tooth colour became worse after 3 months (the average value was equal to 7,21±0,35) and one year later they virtually returned to the initial state (prior to the whitening course) with the average value of 8,07±0,41. In groups 2 and 3, where the patients were using whitening methods together with the remineralizing therapy, valid changes in tooth colour were not registered during the whole year. The result achieved during

6 the course of the aesthetic treatment was successfully maintained during the whole period of observation. Increased tooth sensibility In some patients tooth sensibility appears after the first whitening procedure and it is worth mentioning that it does not appear immediately after the procedure completion but only a day later. In our investigation the increased tooth sensibility appearing one day later after the very first whitening manipulation was registered just in group 1. The maximum number of the patients take notice of the dental hyperesthesia at the end of the first week of the at-home dental bleaching procedure. In group 1 we observed the increase in the number of cases of tooth sensibility: after a day the dental hyperesthesia was registered in 32% of the patients while one week later it was found in 61% of them. One month later after the whitening course completion the hyperesthesia prevalence in group 1 dropped to the level of 36%, which is 3,3 times higher prior to whitening (pic. 2). In groups 2 and 3 the number of cases of the increased tooth sensibility dropped during whitening treatment and the hyperesthesia prevalence was below the initial level during the whole period of observation. Dental caries All the patient undergoing the dental bleaching procedure had either a high or average degree of the enamel resistance to the carious process (the average DMF value amounted to 12,35 in the groups under investigation. No demineralization foci were found).

7 While assessing the degree of the dental caries intensity in patients from group 1, this index value rose and amounted to 14,26 ±0,03, which corresponded to the high degree of the caries intensity. In patients from group 2 DMF index was equal to 12,47±0,07 one year later. In patients from group 3 the average value of DMF index equaled to 12,67±0,07 after one year. It means that group 1 had the maximum annual increment of the dental caries intensity, which amounted to 1,91 and was authentically higher in contrast to groups 2 and 3 (pic.3). The minimum rate of dental caries increase was registered in group 2, where the remineralizing therapy was implied through the use of R.O.C.S. Medical Minerals gel. Calcium content in saliva Despite the fact that the analysis of the calcium content in the oral cavity fluid did not detect any reliable differences in the groups of patients during the whole investigation period, this question is of indisputable interest (pic. 4).

8 From our view point, this phenomenon can be explained in such a way: in groups 2 and 3 the calcium content was replenished at the cost of remineralizing preparations while in group 1 it was washed out from the dental enamel, which was clinically proved by the high increment of the DMF index together with high level of dental hyperesthesia occurrence in this group. In the current clinical investigation they used calcium glycerophosphate as a source of calcium and phosphorus for tooth remineralization. It is common knowledge that the dental remineralization process is supported by enzymes. To be precise, the inclusion of phosphates and calcium into the dental enamel gets significantly activated under the influence of phosphatases. Calcium glycerophosphate is a substrate for the alkaline and acid phosphatases. As a result of hydrolysis of calcium glycerophosphate as well as enzyme impact ions of calcium and phosphate are released. The energy, which is also released during hydrolysis, is believed to be used for ion transference into the dental enamel. Investigations with the use of immobilized alkaline phosphatase conducted at the Central research institute of dentistry demonstrated that in comparison with other calcium-phosphate substrates it is glycerophosphate that contributes to the ultimate success of the dental remineralization [4]. Application of R.O.C.S. Medical Minerals gel for tooth remineralization is more comfortable both for a dentist and a patient as the gel is a finished form suitable for home and ambulatory conditions. The classical scheme of remineralizing therapy, which received its implementation in group 3, requires attending the dentist s room at a regular basis, which is not convenient for many modern patients. The absence of age and ecological limits that could influence upon the regular and prolonged use of this gel can be undoubtedly regarded as an important advantage of the product.

9 CONCLUSIONS The analysis of the results obtained during the current clinical investigation demonstrates that while conducting the at-home dental bleaching manipulations it is reasonable to supplement the aesthetic treatment algorithm with renewing procedures, where the enamel and dentine remineralization with a help of calcium and phosphate, basic elements of hydroxyapatite, is the most essential one. The combination of dental bleaching methods and the remineralizing therapy ensured the following: Improvement of results of the at-home tooth whitening by 65% on average with these results remaining unchanged for not less than a year. Elimination of the risk of dental hyperesthesia appearance, which is the most widespread complication after tooth bleaching. 83% drop in the risk of dental caries development. The use of R.O.C.S. Medical Minerals gel as a remedy for the remineralizing therapy decreases the caries risk by 93%.