The unique environment of the mouth challenges any material seeking to form a lasting bond with teeth. Dental adhesion requires securing a restoration within a space characterized by constant moisture, extreme temperature fluctuations, and significant chewing forces. For a material to function as a dental “glue,” it must withstand these conditions while integrating safely with the living tooth structure. Professional dental materials are highly specialized and engineered to meet these biological and physical demands.
Why Household Adhesives Are Unsafe
The chemicals in common household adhesives, such as cyanoacrylate (Super Glue), are fundamentally incompatible with the biological structures of the mouth. These products are not designed to be biocompatible and release substances that cause direct harm to oral tissues. The liquid adhesive contains unreacted monomers, which are cytotoxic to living cells for up to two weeks, even after the glue hardens.
A significant danger is the exothermic reaction that occurs when cyanoacrylate polymerizes in the presence of moisture. This rapid chemical process generates heat, which can be transmitted through the dentin and potentially cause irreversible damage to the underlying pulp tissue. Heat damage to the pulp may necessitate a root canal procedure or, in severe cases, tooth extraction.
Beyond chemical risks, household glues offer no reliable long-term mechanical strength in the mouth. Saliva and chewing forces rapidly degrade the bond, causing quick failure. Furthermore, applying household glue to a broken tooth or detached crown complicates professional treatment. A dentist must perform extensive work to completely remove the hardened adhesive before a proper, lasting repair can be attempted.
The Science of Professional Dental Adhesion
The materials used in dentistry are categorized as luting agents or bonding agents, functioning through chemical or micro-mechanical retention rather than simple surface stickiness. For indirect restorations (crowns, bridges, and inlays), dentists use specialized luting agents or cements. Modern resin cements are preferred for their strong bonding capabilities and ability to form a durable seal between the restoration and the tooth.
Glass Ionomer Cements offer the advantage of releasing fluoride over time, providing a therapeutic benefit that protects the tooth from recurrent decay. These cements form a chemical bond with the tooth structure, securing the restoration and preventing microleakage—the infiltration of oral fluids and bacteria into the microscopic gap. This creates a long-lasting barrier against the harsh oral environment.
For direct restorations like composite fillings, dentists utilize a multi-step bonding system for micro-mechanical retention. The process begins with an acidic etching agent that roughens the enamel and demineralizes the dentin, creating microscopic pores. A primer and bonding resin are then applied, infiltrating these spaces and the dentin’s collagen network. This forms a “hybrid layer,” where the resin chemically interlocks with the tooth structure, providing a stable, durable, and biocompatible bond.
Immediate Steps for Dental Emergencies
If a dental restoration, such as a crown or filling, breaks or becomes loose, the first step is to contact a dental professional immediately for an urgent appointment. While waiting for professional care, gently rinse your mouth with warm water to clear the area of any debris. If a crown or tooth fragment is retrieved, it should be kept in a clean container. A natural tooth fragment, in particular, should be stored in milk or saliva to help preserve the vitality of the cells.
Any sharp edges on the remaining tooth should be carefully covered with a piece of dental wax or a temporary covering of sugar-free chewing gum to prevent irritation to the tongue and cheek. If you are experiencing discomfort, an over-the-counter pain reliever like ibuprofen can be taken to manage the pain and any associated inflammation. Avoid chewing on the side of the mouth with the damaged tooth or restoration to prevent further breakage.
You can purchase temporary dental cement from a pharmacy, which is intended for the short-term reattachment of a loose crown. If the crown is still intact, carefully clean the inside, place a small amount of the temporary cement inside, and gently attempt to seat it back onto the tooth. This should be considered a very temporary measure, and chewing on the crown must be avoided, as only a dentist can ensure a proper seal and secure fit for the restoration.