- The main organic matrix of dental enamel is primarily composed of amelogenins and enamelins.
- These proteins play a crucial role in the formation and mineralization of enamel, which is the hardest tissue in the human body.
- Amelogenins constitute the majority of the enamel matrix proteins and are essential for the regulation of hydroxyapatite crystal growth and enamel rod formation.
- Enamelins, although present in smaller amounts compared to amelogenins, are critical for the structural integrity and proper mineralization of enamel.

The other options such as collagen and keratin, fibronectin and laminin, and elastin and chondroitin sulfate are associated with other tissues like dentin, connective tissue, and extracellular matrix components but are not significant constituents of enamel.

Therefore, understanding the role of amelogenins and enamelins is fundamental in dental biology and in developing treatments for enamel defects.

Reference: Orban's Oral Histology, 14th Edition, Chapter 6: Dental Enamel / Page 110-115