Sinus dental implant

A sinus dental implant for implanting into an alveolar hole on a patient’s upper gum, comprising:

• a main body having two opposite ends defined as a drilling end and a connection end, and an embedment peripheral surface extended from the drilling end toward the connection end;
• and the drilling end having an outer peripheral area formed into a drilling zone capable of contacting with a bottom of the alveolar hole and a sunken central area formed into a recess surrounded by the drilling zone;
• an external thread being formed on the embedment peripheral surface of the main body to extend in a first spiral direction for engaging with a side wall surface of the alveolar hole;
• and
• a plurality of spiral cutting flutes being formed on the main body and the external thread to extend from the drilling zone toward the connection end in a second spiral direction, which is opposite to the first spiral direction, and a cut being formed between every spiral cutting flute and the recess for communicating the spiral cutting flute with the recess;
• and
• the sinus dental implant being characterized in that the drilling zone is divided by the spiral cutting flutes into a plurality of drilling segments that are circumferentially spaced along the recess;
• and that every drilling segment has a lowest portion defined as a lower drilling portion, from the lower drilling portion of the drilling segment rises gradually toward one of the spiral cutting flutes to form an upper drilling portion, so that a guide surface is formed between the lower drilling portion and the upper drilling portion while a guide space is also formed between the lower drilling portion and the upper drilling portion to communicate with the recess and the spiral cutting flute.