Microplastics in Dentistry—A Review
159
drug, and cosmetic products are called primary microplastics [9, 14]. Degradation
or fragmentation of larger plastic debris, by UV-radiation and mechanical abrasion
results in the formation of secondary microplastics [57]. Microplastics thus released
to the environment affects the environment due to the release of chemicals present in
them either in the form of additives originating from plastics itself or as chemicals
absorbed from surrounding.
Additives give the desired qualities of color and transparency and also resist
degradation from ozone, temperature, bacteria, and thermal and electrical resistance
[26]. Many of these chemicals have negative effects on the health of human as they
have proven to be endocrine disruptors like Bisphenol A (BPA), phthalates, as well
as some of the brominated flame retardants [12]. Endocrine disrupting chemicals
(EDC) can alter the homeostasis of the endocrine system. They can antagonize the
action of natural hormones, alter the pattern of synthesis [13, 41].
The exposure of these chemicals in the field of dentistry is of great concern with
the presence of them in the dental restoration composites as resin composites have
become a viable alternative to the dental amalgam. Composites are more advantageous than amalgam due to their aesthetic and desirable methods of restoration.
These features often makes it preferable and outweigh the local risks associated [4].
The typical application of polymers in the field of dentistry relates to the use in
dentures, fillers, and impression materials.
Transmission of harmful components from these composite resins happens during
clinical application also. These particulates containing part-polymerised monomer
are released into waste water after their polishing and finishing process. These particulate matter finally reach the water bodies. There is an increase in the usage of
highly polymerised RBC for the manufacture of dental crowns, inlays, and onlays
which create fine micro-particle waste powder in large volumes during the milling
process, and gets released into municipal wastewater. These all add to the woes of
the microparticulate and particularly microplastic pollution in environment.
European food safety authority (EFSA) has revised the daily tolerable limit of
BPA in food intake to a temporary level of 4 µg/kg bw/day which is far lower than
the limits they have prescribed earlier. Until 2015 the limit was put at 50 µg/kg
bw/day. There is significant uncertainty exists among the practitioners and scientists
regarding the cytotoxicity of these chemicals on human body. Based on the studies
conducted it is worthwhile for the clinician to understand the potential toxicity of
the chemicals they administer on the patients and the protective procedures that they
can adopt.
There is a great dearth and uncertainty in terms of the studies related to polymer
exposure from dental materials [36] among practitioners. Though significant number
of cross-sectional studies on knowledge on hazardous and general waste among
practitioners is conducted, it would be worthwhile to have a similar study on another
potential area of toxicity like polymer exposure from dental materials. A summary of
the current studies being done in the field of dentistry related to microplastic usage
is listed in Table 1. This chapter would address the current studies being done in
159
drug, and cosmetic products are called primary microplastics [9, 14]. Degradation
or fragmentation of larger plastic debris, by UV-radiation and mechanical abrasion
results in the formation of secondary microplastics [57]. Microplastics thus released
to the environment affects the environment due to the release of chemicals present in
them either in the form of additives originating from plastics itself or as chemicals
absorbed from surrounding.
Additives give the desired qualities of color and transparency and also resist
degradation from ozone, temperature, bacteria, and thermal and electrical resistance
[26]. Many of these chemicals have negative effects on the health of human as they
have proven to be endocrine disruptors like Bisphenol A (BPA), phthalates, as well
as some of the brominated flame retardants [12]. Endocrine disrupting chemicals
(EDC) can alter the homeostasis of the endocrine system. They can antagonize the
action of natural hormones, alter the pattern of synthesis [13, 41].
The exposure of these chemicals in the field of dentistry is of great concern with
the presence of them in the dental restoration composites as resin composites have
become a viable alternative to the dental amalgam. Composites are more advantageous than amalgam due to their aesthetic and desirable methods of restoration.
These features often makes it preferable and outweigh the local risks associated [4].
The typical application of polymers in the field of dentistry relates to the use in
dentures, fillers, and impression materials.
Transmission of harmful components from these composite resins happens during
clinical application also. These particulates containing part-polymerised monomer
are released into waste water after their polishing and finishing process. These particulate matter finally reach the water bodies. There is an increase in the usage of
highly polymerised RBC for the manufacture of dental crowns, inlays, and onlays
which create fine micro-particle waste powder in large volumes during the milling
process, and gets released into municipal wastewater. These all add to the woes of
the microparticulate and particularly microplastic pollution in environment.
European food safety authority (EFSA) has revised the daily tolerable limit of
BPA in food intake to a temporary level of 4 µg/kg bw/day which is far lower than
the limits they have prescribed earlier. Until 2015 the limit was put at 50 µg/kg
bw/day. There is significant uncertainty exists among the practitioners and scientists
regarding the cytotoxicity of these chemicals on human body. Based on the studies
conducted it is worthwhile for the clinician to understand the potential toxicity of
the chemicals they administer on the patients and the protective procedures that they
can adopt.
There is a great dearth and uncertainty in terms of the studies related to polymer
exposure from dental materials [36] among practitioners. Though significant number
of cross-sectional studies on knowledge on hazardous and general waste among
practitioners is conducted, it would be worthwhile to have a similar study on another
potential area of toxicity like polymer exposure from dental materials. A summary of
the current studies being done in the field of dentistry related to microplastic usage
is listed in Table 1. This chapter would address the current studies being done in