The explanation of new dynasty beginning could probably be only the fact, that its founder Teti wasn't a son of Pharaoh Unas, but his son-in-law. The length of his reign is not known, but Manetho set it for 30 years in his lists.
We don’t know much about Teti’s reign and his actions. Teti provided privileges to the temple in Abydos (Abdju) and took part in expansion of goddess Hathor worshipping in Dendera.
Teti’s pyramidal complex in Saqqara
Teti let build his pyramidal complex in northern Saqqara, several hundred of meters from known step pyramid of the King Djoser. Teti’s pyramid was quite small, it measured about 43 meters with the base of size 64 x 64 meters. Only a mound of rocks and grit preserved from it till the present.
Teti’s pyramid was built from not thoroughly worked blocks of granite. The remains of its inner part are extensively damaged by both, the burglars and ravages of time. But a great part of the Pyramid Texts was preserved, by which the pyramid was decorated. Surprisingly the Teti’s sarcophagus was preserved as well.
Most of the Teti’s period dignitaries is buried around his pyramid. Some of the pyramids were destroyed intentionally still at the time of the ruler’s reign. This can be a sign of a fact, that Teti settled accounts hard with his opposition, because such a punishment meant no after death existence of the dissents.