Journal
of Otal
Rehahililation.
1992, Volutiic 19, pages 1 1 1 - 1 1 3
The antimicrobial effect of an iron-binding agent on Streptococcus mutans M . S . B A PN A , S . M U K H E R.) E E (/»(/ R . M U R P H Y Utiiversity of Illinois at Chicago. College of Dentistry, Chicago, Illinois, U.S.A.
Summary The antitnicrobial activity of 2,2'-bipyridine, an iron-binding agent, was investigated by incorporating this agent into Scotchbotid® detUal adhesive resiti. The growth of Streptococcus nititaits on the surface of r'esiti, media atid culture vessel was determined by optical density measurements. It was observed that 2,2'-bipyridene exhibited excellent antimierobial properties. Introduction The control of plaqtre, gingivitis and periodontitis by antimicrobial cliemotlicrapeutic measures is desirable for a number of reasons (Guggenheim & Sclitnid, 1989). The antitnierobial activity of agents can be understood in tertns of their ability to inhibit bacterial growth through various bacteriocidal or baeteriostatic mechanisms. Such mechanisms include inhibition of essential metabolic or synthetic processes, or' interference with membrane functions. A non-bacteriocidal approach may involve inhibition of bacterial colonization by blocking or altering receptor sites on pellicle or bacterial surfaces. An ideal chemotherapeutic cotnpoirnd for control of the plaque has not yet been identified (The .lournal of the American Dental Association, 1986). In this paper we describe the antibiotic activity of a chetnieal that deprives the bacteria of nutritional elements required for their growth. Iron is known to be an cssetitial eletnent for the growth of micro-organisms because it is required at various stages of cell metabolism (Latikforxl, 1973; Neilatids, 1981). Furthermore, several studies have rejiortcd that the addition of iron enliatices the gr'owth of pathogens (Wcinbcrg, 1978; Bullen, 1981; Finkelstein et al., 1983) and bacterical virulance (Hill, 1978; Weinbcrg, 1978; Bullen, 1981; Finkelstein et al., 1983). Thus a decrease in unbottnd iron in the saliva and ccrvicular fiuid could have a ehemotherapeutic effect on the control of plaqtre, gingivitis and periodontitis. In an earlier paper (Bapna et al., 1988), the antimicrobial activity of several chemical agents was reported. The antimicrobial effect of these agents was measured by incorporating them into Scotchbond® dentitie adhesive* resin and following the tiiethod of Evans et al. (1977). This study showed that sodittm fiuoride and dodecylamine, an organic amine, exhibited excelletit antimicrobial properties, while chelating agetits such as vanillic acid, syringic acid, and ethylcnediamitie-ti,n' diacetic acid (EDDA) were not effective as antimicrobial agents. * 3M Co.. St Paul, Minnesota, U.S.A. Cortespondetiee: Dr M.S. Baptia, Utiiversity of Illinois, College of Detitistry, Departtiient of Prosthodonties, 8t)l S. Paulina Street, Chicago. IL 6t)612, U.S.A. Ill
112
M.S. Bapna et al.
Materials and melhods 2,2' Bipyridinc (C|()H2N2)* is known as ati iroti binding agent, and is used as a reagent for the determination of iron. This compound was incorporated into Scotchbond® dentine adhesive resin at a eoncentration ranging from 25 — 50 wt% by stirring the cotnpound into the liquid resin for L5—20s and pouring the mix into a cylindrical tnould for preparation of 4 x 8 m m samples. Control samples (Scotchbond® resiti alone) were prepared similarly. The details of the procedure for testing these samples for antibacterial activity, and the analysis of the results have been described previously (Bapna el al., 1988). Brielly, 10 to 12 samples of each type wer'c separately strspetided in cultures of .V. intitans in TYS Brotlif contaitiing 1% sucrose. Samples vver'e transferred to tubes of fresh broth after 24h. After incubation for a Further 24h, the cells adherent to the resin, to the test-tube, and in the medium were eaeh transferred to 2 ml of 0-1 N NaOH solution. The optieal density (OD) of each of the three fractions was measured at 54()titn oti a Colemati 55 Spcctrophotometcr:!: in a cuvette with a 1-cm light path. The total OD, the resin-adherent OD ol the test and the control samples were used as described previously (Bapna et al., 1988) to calculate the percentage distribution and per"centage inhibition of adherent cells in the test samples. Results and di.scussion
It was expected that the bipyridine would fortn a stable cotnplex by chelating iroti, and would effectively cut off the supply of free iron for' bacterial growth. Table 1 shows the results obtained for test and control samples. A reduction iti total optical density due to the presence of bipyridine in the resin compared to the control total is indicative of inhibition o'i bacterial gr'owth by the compound. The results show that
Table I. Effect of 2—2' bipyridine in dentine adhesive resin oji bacterial attachment ami growth
of Otal
Rehahililation.
1992, Volutiic 19, pages 1 1 1 - 1 1 3
The antimicrobial effect of an iron-binding agent on Streptococcus mutans M . S . B A PN A , S . M U K H E R.) E E (/»(/ R . M U R P H Y Utiiversity of Illinois at Chicago. College of Dentistry, Chicago, Illinois, U.S.A.
Summary The antitnicrobial activity of 2,2'-bipyridine, an iron-binding agent, was investigated by incorporating this agent into Scotchbotid® detUal adhesive resiti. The growth of Streptococcus nititaits on the surface of r'esiti, media atid culture vessel was determined by optical density measurements. It was observed that 2,2'-bipyridene exhibited excellent antimierobial properties. Introduction The control of plaqtre, gingivitis and periodontitis by antimicrobial cliemotlicrapeutic measures is desirable for a number of reasons (Guggenheim & Sclitnid, 1989). The antitnierobial activity of agents can be understood in tertns of their ability to inhibit bacterial growth through various bacteriocidal or baeteriostatic mechanisms. Such mechanisms include inhibition of essential metabolic or synthetic processes, or' interference with membrane functions. A non-bacteriocidal approach may involve inhibition of bacterial colonization by blocking or altering receptor sites on pellicle or bacterial surfaces. An ideal chemotherapeutic cotnpoirnd for control of the plaque has not yet been identified (The .lournal of the American Dental Association, 1986). In this paper we describe the antibiotic activity of a chetnieal that deprives the bacteria of nutritional elements required for their growth. Iron is known to be an cssetitial eletnent for the growth of micro-organisms because it is required at various stages of cell metabolism (Latikforxl, 1973; Neilatids, 1981). Furthermore, several studies have rejiortcd that the addition of iron enliatices the gr'owth of pathogens (Wcinbcrg, 1978; Bullen, 1981; Finkelstein et al., 1983) and bacterical virulance (Hill, 1978; Weinbcrg, 1978; Bullen, 1981; Finkelstein et al., 1983). Thus a decrease in unbottnd iron in the saliva and ccrvicular fiuid could have a ehemotherapeutic effect on the control of plaqtre, gingivitis and periodontitis. In an earlier paper (Bapna et al., 1988), the antimicrobial activity of several chemical agents was reported. The antimicrobial effect of these agents was measured by incorporating them into Scotchbond® dentitie adhesive* resin and following the tiiethod of Evans et al. (1977). This study showed that sodittm fiuoride and dodecylamine, an organic amine, exhibited excelletit antimicrobial properties, while chelating agetits such as vanillic acid, syringic acid, and ethylcnediamitie-ti,n' diacetic acid (EDDA) were not effective as antimicrobial agents. * 3M Co.. St Paul, Minnesota, U.S.A. Cortespondetiee: Dr M.S. Baptia, Utiiversity of Illinois, College of Detitistry, Departtiient of Prosthodonties, 8t)l S. Paulina Street, Chicago. IL 6t)612, U.S.A. Ill
112
M.S. Bapna et al.
Materials and melhods 2,2' Bipyridinc (C|()H2N2)* is known as ati iroti binding agent, and is used as a reagent for the determination of iron. This compound was incorporated into Scotchbond® dentine adhesive resin at a eoncentration ranging from 25 — 50 wt% by stirring the cotnpound into the liquid resin for L5—20s and pouring the mix into a cylindrical tnould for preparation of 4 x 8 m m samples. Control samples (Scotchbond® resiti alone) were prepared similarly. The details of the procedure for testing these samples for antibacterial activity, and the analysis of the results have been described previously (Bapna el al., 1988). Brielly, 10 to 12 samples of each type wer'c separately strspetided in cultures of .V. intitans in TYS Brotlif contaitiing 1% sucrose. Samples vver'e transferred to tubes of fresh broth after 24h. After incubation for a Further 24h, the cells adherent to the resin, to the test-tube, and in the medium were eaeh transferred to 2 ml of 0-1 N NaOH solution. The optieal density (OD) of each of the three fractions was measured at 54()titn oti a Colemati 55 Spcctrophotometcr:!: in a cuvette with a 1-cm light path. The total OD, the resin-adherent OD ol the test and the control samples were used as described previously (Bapna et al., 1988) to calculate the percentage distribution and per"centage inhibition of adherent cells in the test samples. Results and di.scussion
It was expected that the bipyridine would fortn a stable cotnplex by chelating iroti, and would effectively cut off the supply of free iron for' bacterial growth. Table 1 shows the results obtained for test and control samples. A reduction iti total optical density due to the presence of bipyridine in the resin compared to the control total is indicative of inhibition o'i bacterial gr'owth by the compound. The results show that
Table I. Effect of 2—2' bipyridine in dentine adhesive resin oji bacterial attachment ami growth
