Uses
Topical anesthesia is a local anesthesia that is mainly used to numb an external area of our skin. Its use helps in controlling the pain, which is associated with certain procedures, which require laceration repair. It is used to avoid using local anesthesia injections, which cause a lot of pain. It can be used for relieving itching and pain caused by small cuts, poisonous plants, insect stings and bites, minor burns and sunburns, skin eruptions, like in chickenpox, and scratches.
It can also be used in optometry and ophthalmology for numbing the surface around the eye. Certain topical anesthetics, like oxybuprocaine, can also be used in otolaryngology. Manual Small Incision Cataract Surgery or MSICS also uses topical anesthesia. It is used in various mucous membrane and skin conditions. It is sometimes also used as a local analgesia on undamaged skin. It is also used for numbing the inner side of our nose, throat, ear, genital area and anus. (Mace, 2005)
Topical anesthesia is also used for minimizing the discomfort and pain experienced during a routine hysteroscopy by endometrial biopsy, which diagnoses infertility and in endometrial pathology. It is sometimes also used to determine whether the pain felt by the patient is coming from the surface of his body or from inside of his body which the tropical anesthesia is not able to touch. Topical anesthesia is available as jellies, lotions, ointments, aerosols, patches, sprays and creams. Some topical anesthetics are – tetracaine, proparacaine, oxybuprocaine, benzocaine, proxymetacaine, pramoxine, lidocaine, dibucaine and butamben.
Depth of penetration
The depth of penetration for the topical anesthetics typically ranges from 2 to 4 mm, plus or minus 1 mm. (Mace, 2005)
Oraqix and Dentipatch
Oraqix is a non-injectable local anesthetic gel, which has been specifically designed and used for Scaling / Root Planning (SRP) procedures in dentistry. It looks like a liquid and comes in 1.7 gm dental carpules. It has been marked as a periodontal gel and its each carpule contains 2.5 % of prilocaine and 2.5 % of lidocaine, i.e. they are in a 1:1 weight ratio, and thermosetting agents. Unlike other local anesthetics that have to be injected, Oraqix has to be applied around the periodontal pocket by a particular blunt tip applier. (Kumar, 2002)
On the other hand, Dentipatch is an oral transmucosal release system, which comes as an anesthetic dental patch. It is a very small adhesive band containing lidocaine, which is frequently used in dentistry. It prevents pain caused during soft tissue dental operations and by oral injections. Thus, instead of injecting us with local anesthesia our dentists can simply place the adhesive strip on our gum numbing the area within minutes before giving an injection. (Kumar, 2002)
The main difference between Oraqix and Dentipatch is that the first comes as a gel while the latter comes as an adhesive strip. Oraqix contains prilocaine along with lidocaine while Dentipatch only contains lidocaine. The duration of Oraqix is around 20 minutes but Dentipatch remains effective even up to 45 minutes. Oraqix works by becoming gel when we expose it to body temperature. Only the tissues around the periodontal pocket get affected. Dentipatch sticks to our dry gingival tissues and releases the anesthetic through our mucous membranes present inside the mouth. However, while Oraqix can be applied anywhere inside the mouth, Dentipatch can only be placed in dry areas. (Mace, 2005)
References
Kumar, Chandra M. Chris Dodds, Gary L. Fanning; 2002; Ophthalmic Anaesthesia; Taylor & Francis.
Mace, Sharon E. & James Ducharme, Michael F. Murphy; 2005; Pain Management and Sedation: Emergency Department Management; McGraw-Hill, Medical Pub. Division.