Introduction
A little more effort is required when it comes to taking care of oral hygiene especially having done restorative dental procedures. Dental restoratives, like fillings, are essential for maintaining the structure and function of teeth. But there is always a chance that bacteria will get a hold of these restorations and develop biofilms around them, which could result in secondary caries (cavities that occur in the margins of a dental restoration) and restoration failure. Antimicrobial compounds are being added as an extra protective layer to sort this out.
What Is the Need for an Antimicrobial Addition to Dental Restoratives?
Modern-day nanofillers, ceramic fillers, resin fillers, and different types of commercially manufactured tooth-based composite fillings have some form of antimicrobial agents incorporated into them. But why is adding an antimicrobial element within the dental filling? Is not simple oral hygiene recommended by the dentist effective enough to prevent restorative failure?
According to dental research, modern restorative and conservative dentistry materials are focused on preventing bacterial adhesion to the filling material itself.
Oral bacteria, as we know, are capable of adhering both to hydrophobic (the property of a substance that repels water) and hydrophilic (having an affinity for water) surfaces. Further, a dental hypothesis exists that, because of the major and complex influence of electrostatic mechanisms, mainly like the Van der Waals forces, are responsible for the establishment of biofilm on the surface of dental fillings or restorations, causing subsequently a surface deterioration of the dental filling or restorative material used by the dentist and causing the restoration to fail or secondary caries to develop.
Oral bacteria can easily get attached to common restorative materials such as amalgam, gold, ceramic composites, resin composites, glass ionomer cement, and even the nanohybrid fillers used in present-day dentistry. To however help the dentist achieve long-term restorative or filling material success, it is imperative, hence to consider the research-based facts about restorative failure. Let us explore these facts.
Can Biofilm Form Over a Filled Tooth?
The oral cavity hosts a broad diversity of several microbial species or even bacteria that do have the innate potency to colonize your mouth. Which surfaces are more prone to microbial colonization? The most common surfaces are the tooth enamel (the outer covering of teeth that protects the tooth crown from damage and cavities), the tongue, and the oral mucosal membranes. The bacterial adhesion and proliferation on the tooth surface is what is called the dental biofilm, which is the initiator of dental plaque and calculus deposits as well.
Once initiated, dental plaque grows in favorable conditions, leading to the development of pathogenic bacteria. Whether in the absence of proper dental hygiene or lack of regular dental prophylactic visits at your dentist, this can be one of the main reasons for dental calculus deposits to harbor and develop more bacterial adhesion over time, which harbors the gram-negative anaerobes that can survive in the oral cavity and can initiate a range of gingival and periodontal infections. So what exactly is the link between this microbial contamination in the oral cavity and the type of restoration or dental filling material that your dentist is going to choose for your dental cavities?
Why Does Restorative Failure Happen?
Restorative failures occur when dental material used to fill the cavity does not provide a proper marginal seal against bacterial biofilm. A restorative or dental filling failure is when the dental material that has been used to fill the cavitation is simply not effective enough to create a good marginal seal against the bacterial biofilm or adhesion. A break in the marginal integrity or the dental filling seal can easily cause a penetration or permeability that increases this pathogenic bacterium back into the dental filling, creating a sequel called "secondary dental caries" that occurs below the dental fillings.
This brings us to the importance of why dental restorative materials need to be effective not only for esthetic or masticatory/choking functions but also for being stronger in terms of material and deformation resistance against pathogenic microbes or bacteria. It is indeed obvious, is not it, that when the bacterial microleakage occurs within the dental filling placed by your operator or dentist, you will be prone to facing restorative failure or evident issues with the dental filling material.
What Are the Different Options for Antimicrobial Agents?
So what are the different options for antimicrobial add-ons to dental fillings in modern-day practice? Most resin-based and glass ionomer cement are usually composed of superior properties like fluoride-releasing ability that can promote the remineralization of tooth enamel. Apart from acting as a potent dental filling, dental materials usually made of gold and its alloys used for restorative purposes are known to naturally prevent bacterial biofilm accumulation.
Most temporary fillings or even the interim or intermediate restorative materials that have lesser mechanical properties in comparison to permanent dental fillings (usually used for very deep carious lesions by your dentist for a short healing period or post-endodontic treatment are usually incorporated with antimicrobial and anti-inflammatory properties to prevent bacteria microleakage into the tooth. The common temporary filling material that has both these beneficial properties is a mixture of Zinc oxide and Eugenol. However, the drawback of temporary filling materials is that they do not have any mechanical resistance and are subject to easy fracture upon mastication. Hence glass ionomers and resin-based fillers or nanohybrid modern-day fillers that have antimicrobial agents incorporated as per the manufacturer of the dental filling commercial brand, would usually be the choice of material for counteracting bacterial biofilm formation on the filling or restorative surface.
The incorporation further of one percent CHX (Chlorhexidine diacetate) with improved antimicrobial resistance coupled with better fluoride-releasing properties of glass ionomers or other hybrid composites are classic examples of materials that can inhibit bacterial biofilm.
Dental research gives an insight into the need for professional consideration in the manufacture of dental filling materials because there would be not only a need for improved physical, chemical, and biological characteristics of the dental filling material used but also a need to counteract the microbial potency of the oral cavity to make the dental restoration or filling treatment successful.
Presently, the recommendations based on antimicrobial add-ons into the dental material are by incorporation of five, ten, fifteen or even up to 30 percent of the requisite agent to prevent restorative failure.
Conclusion
To conclude thus, restorative failure management in modern conservative and restorative dentistry is managed by the research-based benefits of antimicrobial elements that can be added into the dental fillings or restorative material for counteracting the bacterial biofilm formation and to prevent microleakage of bacteria into the fillings. Your dentist can give you an insight as well regarding the type of filling material used in the clinical setting and an overview of its properties.
