**3. Conclusion**

**Figure 4.** a-e: Penetration of radiopaque contrast media in cancellous bone shows penetration after crestal injection on

Our study showed there was a statistically significant difference (p<0.001) in the onset of anesthesia between CA (7.00+0.71 sec) and IANB (3.30+0.67 min). A statistically significant difference was also present (p<0.05) between the duration of anesthesia in CA and IANB which lasted 23.10+2.13 min and 32.10+2.02 min respectively. Thus, the anesthesia was virtually instantaneous for CA and more lasting in IANB. The anesthetic success rates are presented in

axial CT scan.

38 A Textbook of Advanced Oral and Maxillofacial Surgery Volume 2

Table 1.

Although, the CA method or other similar methods of injection such as the intraseptal method (utilizing the alveolar bone nutritional canals) are traditionally considered as supplementary injections, they are successfully used by numerous clinicians as a primary route of anesthetic administration and high success rates of anesthesia and satisfaction both by patients and dentists have been obtained.

The benefits of conventional Intraosseous Injections (I0I) are clearly known. With the advances in this area and introduction of new instruments and techniques patients and dentists benefit from profound anesthesia without unnecessary lip and tongue anesthesia. Unfortunately above facts have not made IOI as popular as the infiltration and block techniques.

Unsuccessful injections in the premolar region may be due to dense cortical bone of mental foramen that acts like a dam and reduces the diffusion rate of anesthetic solution. Also reduced diameter and fewer nutrient canals compared to posterior region may play a role. Reported primary intraligamentary anesthesia success rates of 74-92% were <99% observed in CA. (10) It seems that the high success rate of CA is due to fast (or even immediate) diffusion of anesthetic agent through the very porous region of the tooth socket.

Longer duration of anesthesia in IANB compared to CA was an expected finding. CA produced duration of anesthesia similar to those of reported intraligamentary injection (2).

Another advantage of CA is its 0% of positive aspiration. The above facts might explain the reason for the statistically lesser readings of blood pressure and the heart (pulse) rate. As with intraosseous types of injections, the CA allows bilateral treatment of mandibular areas without complete mandibular numbness or lack of tongue control.

CA injections penetrate the uncomplicated tissue structures aseptically that probably account for mild post injection discomfort (gingival soreness). The presence of anatomical anomalies such as tori at the proposed site of injection would preclude the dentist from using the CA effectively.

Crestal anesthesia is an efficient, fast, and reliable technique in posterior mandibular dental restorative procedures and may be considered as a reliable and safe primary injection method in posterior mandibular teeth for exodontias or restorative dental procedures.
