ORIGINAL PAPERS Dent. Med. Probl. 28, 45, 1, 37 41 ISSN 1644 387X Copyright by Silesian Piasts University of Medicine in Wrocław and Polish Stomatological Association BARTOSZ LEDA 1, TOMASZ NIEDźWIEDZKI 1, TOMASZ ŁUKASZEWSKI 1, BARBARA DOROCKA BOBKOWSKA 2 Carriage of Streptococcus Species and Selected Saliva Properties in Complete Denture Wearers Występowanie bakterii oraz wybrane parametry śliny u użytkowników całkowitych uzupełnień protetycznych 1 Student Research Group, Department of Prosthodontics, University of Medical Sciences, Poznan, Poland 2 Department of Prosthodontics, University of Medical Sciences, Poznan, Poland Abstract Background. Saliva contains many components that interact with microorganisms and hence control the compo sition of the oral microflora. Objectives. The aim of this study was to examine the carriage of on the oral mucosa in acrylic complete denture wearers. Selected properties of saliva were also assessed. Material and Methods. Twenty nine patients (14 men, 15 women) aged 58 to 9, acrylic complete denture wear ers were included in the study. The microorganisms were isolated by culture method, were iden tified using API 2 Strep test (biomerieux, France). The ph of the saliva was examined using a ph meter CP 411 (Elmetron, Poland) equipped with Single Pore Flat electrode (Hamilton, USA). The buffer capacity was assessed by the CRT buffer test (Ivoclar, Liechtenstein). Results. The study revealed the occurrence of 5 types of Streptococcus spp: Streptococcus mitis (15.1%), Streptococcus salivarius (36.4%), Streptococcus oralis (21.2%), Streptococcus sanguis (12.1%), Streptococcus hominis (15.1%). The mean value of saliva ph was 6.89 SD ±.54. The buffer capacity was: high in 1, medium in 16 and low in 3 cases, respectively. Conclusions. The most dominant microorganism was Streptococcus salivarius. A correlation between the buffer capacity and ph of saliva was observed (Dent. Med. Probl. 28, 45, 1, 37 41). Key words: Streptococcus, saliva, complete dentures. Streszczenie Wprowadzenie. Najbardziej dominującym drobnoustrojem występującym w obrębie mikroflory jamy ustnej osób użytkujących ruchome uzupełnienie protetyczne całkowite jest gatunek Streptococccus. Ślina zawiera wiele składników, które wchodzą w reakcję z ww. drobnoustrojami, w ten sposób kontrolując skład środowiska. Cel pracy. Ocena występowania drobnoustrojów rodzaju Streptococcus na błonie śluzowej jamy ustnej pacjentów użytkujących akrylowe uzupełnienia protetyczne całkowite. U badanych oceniono również wybrane parametry śliny. Materiał i metody. Zbadano 29 pacjentów (14 mężczyzn, 15 kobiet), użytkowników uzupełnień protetycznych całkowitych w wieku 58 9 lat. Drobnoustroje wyizolowano metodą posiewu i hodowli. Identyfikację przeprowadzono na podstawie cech morfologicznych i biochemicznych na podstawie testu API 2 Strep (biomerieux, Francja). Wartość ph śliny, oceniono używając ph metru CP 411 (Elmetron, Polska), zaopatrzonego w elektrodę Single Pore Flat (Hamilton, USA). Pojemność buforową śliny oceniono za pomocą CRT buffer test (Ivoclar, Liechtenstein). Wyniki. Wyhodowano drobnoustroje rodzaju Streptococcus następujących gatunków: Steptococcus mitis (15,1%), Streptococcus salivarius (36,4%), Streptococcus oralis (21,2%), Streptococcus sanguis (12,1%) oraz Streptococcus hominis (15,1%). Wartość średnia ph śliny wyniosła 6,89 ±,54. Pojemność buforową śliny oceniono jako: dużą w 1, średnią w 16 i małą w 3 przypadkach. * The study was presented at the 7th International Congress of Young Medical Scientists, May 2 22, 27, Poznań, Poland.
38 B. LEDA et al. Wnioski. U użytkowników uzupełnień protetycznych całkowitych najczęściej izolowano drobnoustroje gatunku Streptococcus salivarius. Stwierdzono korelację między pojemnością buforową i wartością ph śliny (Dent. Med. Probl. 28, 45, 1, 37 41). Słowa kluczowe: Streptococcus, ślina, protezy całkowite. The microbial flora of the oral cavity is rich and extremely diverse. This diversity is due to the fact that the mouth is composed of a various bac teria, viruses ad fungi supplied with a wide range of different nutrients. In addition, this environment is affected by the ph and oxygen levels of saliva, salivary antimicrobial agents, microbial interac tions and salivary flow [1, 2]. Insertion of com plete denture influences the microbial system of the oral cavity. The tissue surface of a maxillary denture in healthy patients was shown to be high ly colonized by a variety of bacteria and yeasts. Many studies provide evidence that a fitting sur face of a maxillary complete denture is particular ly susceptible to microbial colonization. This may be a result of a barrier created by the denture that prevents salivary cleansing that enhances adher ence of microorganisms [3, 4]. Saliva has many essential functions important in the maintenance of oral health. Protection prop erties against bacteria and fungi are based on the salivary antimicrobial action (lysozyme, peroxi dase, secretory immunoglobulin A IgA and his tatins) [5, 6]. Saliva influences the formation of denture plaque and its maturation process and metabolism. Edentulous patients with hyposaliva tion have increased susceptibility to mucosal ulcer ation and candidiasis [1, 5, 6]. It was proved that the amount of microorganisms such as Candida spp., and Staphylococcus spp. play a major role in the development of denture stomatitis [7, 8]. Adhesion of microorganisms to oral mucosa and fitting surface of the denture is a prerequisite for the formulation of denture plaque that may lead to the development of denture stom atitis. Microbial colonization on the acrylic surface is always preceded by the adsorption of an acquired pellicle. The composition of the mature denture plaque is dependent on the primary binding between pioneer bacteria and the acquired pellicle. It was found that bacteria pre dominate in early plaque formation [9, 1]. The aim of this study was to examine the car riage of on the oral mucosa in acrylic complete denture wearers. Selected properties of saliva were also assessed in the above patients. Material and Methods Twenty nine patients (14 men, 15 women) aged 58 to 9 were selected from patients attend ing the Department of Prosthetic Dentistry, Poznan University School of Medical Sciences. The study was approved by the Bioethics Committee. All of patients presented a healthy oral mucosa and a good general health. The patients were informed not to drink and eat for two hours before the collection of the saliva sample. The patients had worn complete acrylic resin dentures for more than one year. The microorganisms were isolated by culture method. Swabs were collected from palatal mucosa, all isolates were identified by microscop ic examination and biochemical tests using API 2 Strep identification kit (biomerieux SA, Marcy l Etoile, France). A paraffin stimulated saliva sample of approx imately 3 ml was collected. ph of the saliva was examined using a ph meter CP 411 (Elmetron, Poland) equipped with a Single Pore Flat electrode (Hamilton, USA). The buffer capacity of saliva was assessed by the CRT buffer test (Ivoclar, Liechtenstein). High, medium, and low salivary buffer capacities were indicated by blue, green, and yellow test fields, respectively. Statistical analysis was performed using Student t test, χ 2 test and Pearson s correlation coefficient. In all tests a probability value (p) of less than.5 was considered significant. Results A total of 33 Streptococcus strains were isola ted from patients. The identity of streptococcal isolates is presented in Figure 1. The most frequ ently isolated bacteria were Streptococcus saliva rius (n = 12; 36.4%); the remaining isolates inclu ded the species of Streptococcus oralis (n = 7; 21.2%), Streptococcus hominis (n = 5; 15.1%), Streptococcus mitis (n = 5; 15.1%) and Streptococ cus sanguis (n = 4; 12.1%). The mean value of salivary ph was 6.89 ±.54 (Fig. 2). The buffer capacity was: high in 1/29, medium in 16/29 and low in 3/29 cases, respectively (Fig. 3). The significant correlation between CRT buffer and ph of saliva was observed (Fig. 4) (p <.5). There was no corre lation between ph, buffer capacity and the car riage of Streptococcus on the oral mucosa (Fig. 5a and 5b).
and Saliva Properties in Complete Denture Wearers 39 % ph 4 35 36.36 8. 7.8 p =.8 3 25 2 15 1 5 21.21 15.15 12.12 15.15 oralis mitis sanguis salivarius hominis Streptococcus oralis mitis sanguis salivarius hominis Fig. 1. Carriage of isolated from palatal mucosa Ryc. 1. Gatunki rodzaju izolowane z błony śluzowej podniebienia ph 9 8 7 7,62 7.6 7.4 7.2 7. 6.8 6.6 6.4 6.2 6. 5.8 5.6 5.4 H high M medium L low CRT buffer capacity of saliva CRT pojemność bufora śliny mean średnia mean ± SD wartość średnia ± odchylenie standardowe mean ± 1.96*SD średnia ± 1,96*SD Fig. 4. Correlation between ph value and buffer capacity (CRT) of saliva Ryc. 4. Korelacja między ph i pojemnością buforową śliny (CRT) 6 5 5,42 presence of obecność Streptococcus spp 4 mean value ± SD: 6.89 ±.54 wartość średnia ± odchylenie standardowe: 6.89 ±.54 Fig. 2. The mean value of ph of saliva in examined population Ryc. 2. Średnia wartość ph śliny w badanej populacji 1 1 = presence of Streptoccocus spp., = lack of 1 = obecność Streptoccocus spp., = brak p =.14 % 6 55.2 5 5.3 5.6 5.9 6.2 6.5 6.8 7.1 7.4 7.7 8 5 4 3 2 1 1.3 34.5 CRT L CRT M CRT H CRT L low buffer capacity mała pojemność bufora CRT M medium buffer capacity średnia pojemność bufora CRT H high buffer capacity duża pojemność bufora Fig. 3. Buffer capacity of saliva (CRT) in examined population Ryc. 3. Pojemność buforowa śliny (CRT) w badanej populacji ph of saliva ph śliny Fig. 5a. Correlation between ph value and occurrence of Ryc. 5a. Korelacja ph śliny a obecnością presence of obecność χ 2 Pearson: p =.64 Discussion There is a specific ecological niche beneath the fitting denture surface and the mucosa, protected from saliva. It contains a large quantity of proteins and glycoproteins which are readily adsorbed to the denture surface. The process of protein adsorption and bacterial adhesion seem to be more important than mechanical retention for the colonization by microorganisms of the fitting denture surface and the underlying mucosa [4, 11, 12]. It was found that predomi nate in early denture plaque formation. The asso ciation between streptococcal activity and denture lack of brak CRT L CRT M CRT H low medium high mała średnia duża buffer capacity of saliva pojemność buforowa śliny Fig. 5b. Correlation between buffer capacity of saliva (CRT) and occurrence of Ryc. 5b. Korelacja między pojemnością buforową śliny (CRT) i obecnością stomatitis was previously established [7, 8, 13]. In the present study, were isolated in 71.3% of the edentulous acrylic complete den ture wearers. These results are in agreement with
4 B. LEDA et al. previous reports where have been isolated from 69.9% of the above patients, Streptococcus oralis was the most commonly iso lated species [7, 8]. It was found that bacteria col onization and subsequent biofilm formation on the denture fitting surface may lead to accumulation of denture plaque and stomatitis [14]. Adherence of microorganisms to the acrylic surface may be described as initial non specific interactions (elec trostatic interaction, van der Waals forces) and specific interactions (receptor ligand binding) [9]. Surface roughness and surface free energy acrylic resin as well as surface characteristics of adhering bacteria also contribute to the process of microbial colonization and denture plaque maturation [15]. Sardin et al. [9] evaluated streptococcal adherence (Streptococcus mitis, Steptococcus parasanguinis, Streptococcus oralis and Streptococcus sanguis) to currently used prosthetic materials, after a salivary coating. They observed a relationship between the number of adherent bacteria and the physicochem ical surface properties of bacteria. The previous study of the edentulous complete denture wearers showed that Streptococcus san guis and Streptococcus salivarius were found mostly in patients with denture stomatitis while Streptococcus oralis and Streptococcus hominis were observed in healthy subjects [7, 8, 13]. It was also demonstrated that streptococci inhabiting oral mucosa or the fitting surface of the denture may participate in the pathogenesis of denture stomati tis by affecting the process of denture plaque for mation. It has been demonstrated that in vitro adherence of Candida albicans to an acrylic sur face increases when it is covered by a layer of Streptococcus sanguis or Streptococcus salivarius [16]. Moreover, it was shown that strains of Streptococcus sanguis, salivarius, mutans and mitis coagglutinate with Candida albicans, may also affect oral mucosal adherence and coloniza tion by yeasts [17]. Saliva contains many components that interact with microorganisms and thus control the compo sition of the oral microflora. Decreased salivary flow rate and alterations in salivary composition may cause an oral imbalance manifested clinically by increased susceptibility to microbial infections [18, 19]. In the present study the correlation between saliva ph value and its buffer capacity was observed, which is in accordance with results of the other workers [2]. The mean value of ph was 6.89, which is regarded as suitable for growing Streptococcus salivarius species [3]. There was no correlation between ph, buffer capacity and the carriage of Streptococcus on the palatal mucosa. The authors concluded that Streptococcus sali varius was the most commonly isolated microor ganism on the palatal mucosa in complete denture wearers. A correlation between buffer capacity and ph value of saliva was observed. References [1] ELIASSON L., CARLEU A., ALMSTAHL A., WIKSTRÖM M., LINGSTRÖM P.: Dental plaque ph and microorganisms dur ing hyposalivation. J. Dent. Res. 26, 85, 334 338. [2] MARSH P.D., PERCIVAL R.S.: The oral microflora friend or foe? Can we decide? Int. Dent. J. 26, 56, Suppl. 1, 233 239. [3] BUDTZ JÖRGENSEN E., THEILADE J., ZANDER H.A.: Method for studying the development, structure and microflo ra of denture plaque. Scand. J. Dent. Res. 198, 89, 149 156. [4] MONSENEGO P.: Presence of microorganisms on the fitting denture complete surface: study in vivo. J. Oral Rehabil. 2, 27, 78 713. [5] MESE H., MATSUO R.: Salivary secretion, taste and hyposalivation. J. Oral Rehabil. 27, 34, 711 723. [6] LIGTENBERG A., DE SOET J., VEERMAN E., van NIEUW AMERONGEN A.: Oral Disseases. From detection to diag nostics. Ann. N.Y. Acad. Sci. 27, 198, 2 23. [7] DOROCKA BOBKOWSKA B., SZUMALA KAKOL A.: Badania mikrobiologiczne jamy ustnej u chorych na cukrzycę typu 2 ze stomatopatią protetyczną. Prot. Stomat. 27, 57, 89 96. [8] SPIECHOWICZ E., MEISEL MIKOLAJCZYK F., NYQUIST G.: Mikroflora jamy ustnej u pacjentow ze stomatopatiami protetycznymi. Prot. Stomat. 1978, 2, 141 152. [9] SARDIN S., MORRIER J., BENAY G., BARSOTTI O.: In vitro streptococcal adherence on prosthetic and implant mate rials. Interactions with physicochemical surface properties. J. Oral Rehabil. 24, 31, 14 148. [1] SMITH D.J., MATTOS GRANER R.O.: Secretory immunity following mutans streptococcal infection or immuniza tion. Curr. Top. Microbiol. Immuno. 28, 319, 131 156. [11] NIKAWA H., HAMADA T., YAMAMOTO T.: Denture plaque past and recent concerns. J. Dent. 1998, 26, 299 34. [12] MAJEWSKI S.: Jakościowy stan mikroflory bezzębnej jamy ustnej przed leczeniem protetycznym i po zastosowa niu protez całkowitych. Prot. Stomat. 1974, 16, 189 198. [13] KOOPMANS A.S.F., KIPPUW N., GRAAFF J.: Bacterial involvement in denture induced stomatitis. J. Dent. Res. 1988, 67, 1246 125. [14] NIKAWA H., JIN C., MAKIHIRA S.: Biofilm formation of Candida albicans on the surfaces of deteriorated soft den ture lining materials caused by denture cleansers in vitro. J. Oral Rehabil. 23, 3, 243 25
and Saliva Properties in Complete Denture Wearers 41 [15] EICK S., GLOCKMANN E., BRANDL B., PFISTER W.: Adherence of Streptococcus mutans to various restorative mate rials in a continuous flow system. J. Oral Rehabil. 24, 31, 278 285. [16] VERRAN J.: Malodour in denture wearers: an ill defined problem. Oral Dis. 25, 11, Suppl. 1, 24 28. [17] BAGG J., SILVERWOOD R.W.: Coagglutination reaction between Candida albicans and oral bacteria. J. Med. Microbiol. 1986, 22, 165 169. [18] NAGLER R.M.: Salivary glands and the aging process: mechanistic aspects, health status and medicinal efficacy monitoring. Biogerontology 24, 5, 223 233. [19] NIEDERMEIER W., HUBER M., FISHER D., BELER K., MULLER N., SCHULER R.: Significance of saliva for the den ture wearing population. Gerodontology 2, 2, 14 118. [2] MORITSUKA M., KITASAKO Y., BURROW M.V., IKEDA M., TAGAMI J.: The ph change after HCL titration into rest ing and simulated saliva for a buffering capacity test. Aust. Dent. J. 26, 51, 17 174. Address for correspondence: Barbara Dorocka Bobkowska Department of Prosthodontics University of Medical Sciences Bukowska 7 6 812 Poznań Poland Tel.: +48 61 85 47 9 E mail: badb@mp.pl Received: 18.2.28 Revised: 2.4.28 Accepted: 28.4.28 Praca wpłynęła do Redakcji: 18.2.28 r. Po recenzji: 2.4.28 r. Zaakceptowano do druku: 28.4.28 r.