Cements and Liners: Your Introductory Guide
You went to your dentist with complaints of a severe toothache, pulpal inflammation, and secondary carriage. After doing an extensive examination, your dentist decided to use restoration materials to minimize the damage. Well, there are several restoration materials available in the market, and cements and liners are just two of them. But the use of restorative materials like cements and liners largely depend on the clinical scenario; for example, remaining teeth, their conditions, and the presence of any other associated oropharyngeal disease.
Sometimes materials are placed on a cavity preparation as a thin coating, largely to offer protection in conjunction with other more solid materials. These thin coatings of materials are referred to as liners. Their primary purpose is to provide protection from chemical irritation. But liners hardly provide any thermal insulation, and cannot add bulk to a deep dental cavity. In addition, liners are not suitable for use within the deep cavity, largely due to their frailty and lack of strength. Hence, their usage is fairly limited in clinical practices. Substances that could be used as liners are – calcium hydroxide, resins, varnishes etc.
Unlike liners, cement has more diverse applications. They can be used as a material that would hold restorative materials in a fixed position within the mouth. In addition to that, cement might also work as filling bases either alone or in conjunction with other strong restorative materials. They basically work by sealing off the micro leakage and shutting off the interface between the teeth and the restorative materials. An ideal cement should be:
- not highly soluble
- should have minimal impact on the overall health of pulp tissue
- High tensile strength
Furthermore, on the basis of the duration cement can be classified into two categories, namely:
- Temporary cement
- Permanent cement