<?xml version="1.0" encoding="utf-8"?><!DOCTYPE Zthes SYSTEM "http://zthes.z3950.org/xml/zthes-05.dtd">  <Zthes><term><termId>31320611</termId><termName>dentin</termName><termType>PT</termType><termNote><![CDATA[ Material comprising the primary, bone-like structure of a tooth. Dentin is hard calcareous material, with less porosity and less organic matter than bone. It is generally covered with a protective enamel layer. Layers of dentin cover animal teeth (whale, hippopotamus, boar, etc.) and tusks (ivory, elephant, walrus, etc.).  ]]></termNote><termCreatedDate>2026-03-30 20:26:25</termCreatedDate><relation><relationType>UF</relationType><termId>31320612</termId><termName>dentine</termName><termType>ND</termType></relation><relation><relationType>BT</relationType><termId>31306176</termId><termName>tooth components as material</termName><termType>PT</termType></relation><relation><relationType>NT</relationType><termId>31344944</termId><termName>ivory</termName><termType>PT</termType></relation><relation><relationType>RT</relationType><termId>31320608</termId><termName>dental enamel</termName><termType>PT</termType></relation></term>  </Zthes>