Many people wonder what happens to human teeth during the cremation process. It is a common misconception that teeth, like other organic materials, simply burn away into ash. Understanding the unique composition of teeth and the specifics of modern cremation reveals a more nuanced outcome than complete combustion.
The Composition of Teeth
Human teeth possess a complex and highly mineralized structure that contributes to their durability. The outermost layer, enamel, is the hardest substance in the human body, composed almost entirely of inorganic mineral salts, primarily a form of calcium phosphate known as hydroxyapatite. This crystalline structure accounts for approximately 96% of enamel’s composition.
Beneath the enamel lies dentin, a calcified tissue that forms the bulk of the tooth. Dentin is also rich in hydroxyapatite, making up about 70-72% of its weight, but it also contains a significant proportion of organic materials, mainly collagen, and water. The innermost part of the tooth, the pulp, consists of soft tissues, nerves, and blood vessels. This dense mineral content, especially in the enamel, provides teeth with a remarkable resistance to heat compared to other body tissues.
The Cremation Process and Tooth Transformation
During cremation, the body is exposed to extreme temperatures, typically ranging from 1400 to 1800 degrees Fahrenheit (760 to 980 degrees Celsius). At these temperatures, the organic components of the teeth, such as the pulp and the organic matrix within the dentin, are consumed through incineration or evaporation. The water content also dehydrates rapidly.
However, the highly mineralized structure, particularly the enamel and the hydroxyapatite in dentin, does not combust in the same way as soft tissues. Instead, the inorganic material undergoes calcification and embrittlement. The teeth become very fragile, discolored, and are prone to fracturing or crumbling into smaller pieces. While much of the tooth structure is affected, the mineral components persist as brittle fragments rather than fully burning away.
From Fragments to Cremated Remains
After the cremation process, what remains are bone fragments and tooth fragments. These materials are collected from the cremation chamber after a cooling period. Any metal items, such as surgical implants, are often removed at this stage.
The remaining bone and tooth fragments are then transferred to a specialized machine known as a cremulator or pulverizer. This device mechanically processes the fragments, reducing them to a fine, uniform consistency. The resulting material, commonly referred to as “cremated remains” or “ashes,” is primarily composed of pulverized bone and tooth fragments and is not true ash from combustion.