Drug which reaches maximum concentration in gingival fluid is:
**Core Concept**
The question is testing the pharmacokinetics of local anesthetics and their ability to penetrate dental tissues. The correct answer requires an understanding of the properties of different local anesthetics and their ability to reach therapeutic concentrations in gingival fluid.
**Why the Correct Answer is Right**
Lidocaine is a widely used local anesthetic that is commonly administered topically or injected into the gingiva for dental procedures. It is a base (pKa 7.9) and thus readily penetrates the lipid-rich dental tissues, including the gingiva. The high lipid solubility of lidocaine allows it to reach maximum concentrations in gingival fluid, making it an effective anesthetic for dental procedures.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because the properties of articaine are similar to those of lidocaine, but articaine has a higher pKa (7.9 vs 7.9), which may affect its ability to penetrate dental tissues.
* **Option B:** This option is incorrect because bupivacaine is a long-acting local anesthetic that is more commonly used for regional anesthesia rather than topical anesthesia in the gingiva.
* **Option C:** This option is incorrect because mepivacaine is a local anesthetic that is similar to lidocaine but has a lower potency and a slightly longer duration of action.
**Clinical Pearl / High-Yield Fact**
When selecting a local anesthetic for dental procedures, consider the patient's age, medical history, and the type of procedure being performed. Lidocaine is a good choice for most dental procedures, but other local anesthetics may be more effective in certain situations.
**Correct Answer: C. Mepivacaine**