In: Anesthesia11 Nov 2009
The DP is not recommended by the manufacturer for use in children younger than 12 years, since the clinical trials have not been performed for children. The DP contained 46.1 mg of lidocaine, which is the equivalent to the amount of lidocaine found in 1.28 cartridges of 2% lidocaine with 1:100,000 epinephrine. The peak lidocaine plasma level for a 15-minute application period is 16-22 ng/mL, which is about one tenth of the peak lidocaine plasma level for an injection of 1 carpule of 2% lidocaine with 1:100,000 epinephrine. Therefore, the DP was determined to have very low toxicity. Based on these pharmacologic data, it was determined that the DP would be safe to use in children.
The decision to use half the DP was based on the assumption that half the DP was long enough to cover the gingival area subjected to the rubber dam clamp. According to the product literature, 20% benzocaine should be applied for 20-30 seconds to be effective. Since the swab was alternated between the facial and lingual gingival tissue for 1 minute, the topical anesthetic was presumed to be as effective as if a full swab had been used for 1 minute. It is possible that half the DP and topical anesthetic were less effective than if a full DP or a full swab was used. Since both the DP and topical anesthetic may have been less effective, the overall results might not have changed.
Generally, enameloplasty is not a painful procedure, but some patients complain that it is painful. The reason that enameloplasty was analyzed was to determine whether it was a confounding variable, which could potentially affect the patient’s pain scores.
The average per-child fraction of DPs that adhered for 5 minutes to the oral mucosa was 29.7%. An interesting finding was that the DP tended to adhere to the oral mucosa more with increased age in girls, but there was no such relationship in boys (Figure 4). None of the other studies that evaluated the DP mentioned the adherence problem of the DP to the oral mucosa. A potential explanation of the variation may relate to salivary flow. Several studies have found that males have higher salivary flow rates than females. The salivary flow rates in both males and females increase with age. The sex difference in salivary flow rates has been observed in children and adults. The fact that females have lower salivary flow rates may be part of the reason that the DP adhered better in girls in our study.
Figure 4. Displaced nonadhesive patch.
There was some tendency for the VAS scores to cluster around the faces on the pain scale slide rule. The first cluster (36 scores) was around the first happy face on the left, which covered VAS scores of 2.5-13. The second cluster (38 scores) was around the second happy face, which covered VAS scores of 24-33.5. The third cluster (14 scores) was around the face in the middle, which covered VAS scores of 45-55. The fourth cluster (8 scores) was around the first sad face, which covered VAS scores of 66-76. The rest of the data were scattered before and between all these clusters, with 52 scores falling between the clusters described herein. Most subjects experienced mild pain.
The pain scores showed that the DP was not superior to the topical anesthetic swab. A post hoc power computation, made using the data from this study, indicated that the study had 90% power to find a difference of 9 mm on the 100-mm scale. Thus, it is highly unlikely that the DP and the topical anesthetic swab differ by even this amount. These findings do not agree with the 2 studies that compared the DP with the topical anesthetic swab. The pain scores in the study by Kreider et al did not show significant results. Kreider et al found a significant decrease in pain sounds when the DP was used, where sounds were measured by applying the Sounds, Eyes, and Motor Scale to the patients’ videotaped be havior. A possible explanation for the difference in results may be related to the longer application period for the DP used in the study by Kreider et al. A better correlation between behaviors may have been observed if the sessions were evaluated from a videotape and if the same behavior rating scale was used. Carr and Hor-ton found that the DP was highly effective for needle-sticks and equally effective for scaling and root planing when compared with the topical anesthetic swab. The treatment application period was not given for the Carr and Horton study, but a longer application period may be the reason for the difference in results.
No significant difference was noted in the pain scores for the maxilla versus the mandible. Carr and Horton also found no difference in the pain scores between the maxilla and mandible as well. One reason that there was no difference is that the DP was applied to the keratinized tissue and the gingival tissue was equally anesthetized.
There was no difference in the pain scores reported for boys and girls. According to a study by Robinson et al, females are more fearful than males; however, generally, no sex differences have been noted with respect to dental fear. In addition, females usually have greater sensitivity to pain when compared with males.
It is possible that the DP was not more effective than the topical anesthetic swab because of the problems with the DPs adhering to the oral mucosa, although pain scores were not significantly related to the fraction of patch adherence (P = .14). It is possible that with a larger sample size a trend may have been clearer. In the cases where the DP did not adhere to the oral mucosa, the lidocaine may have needed to diffuse through a thicker salivary layer before entering the oral mucosa.
Neither the operator nor the subject was blinded to the treatment rendered. The subject was not informed when the different treatments were rendered, but there was a difference in the application and application times for each agent. The patient may have known when the different agents were being used, especially the older subjects. One operator performed all the procedures and therefore interoperator reliability was not an issue. generic tadalafil 20mg
Previous experience of a rubber dam clamp placed on topically anesthetized tissue was not controlled. It is very likely that the older subjects had previous experience with the rubber dam clamp, but this may not be true in the younger subjects. A subject whose previous experience with the rubber dam clamp was painful may have had a preconceived notion that it would be painful this time. Previous dental experiences strongly influence future dental anxiety and fear.
Various rubber dam clamps were used on the teeth that were sealed, since not all teeth are the same size. A record was not kept of the rubber dam clamp size.
Some of the rubber dam clamps impinge more on the gingival tissue and cementum and therefore may cause more discomfort. This could be a confounding factor, although there was no correlation between the pain scores and clamp trouble. Clamp trouble was usually associated with trying to find the correct size of rubber dam clamp.
When a local anesthetic injection is given in young children, the feeling of anesthesia is sometimes interpreted as being painful. This is a common observation in young pediatric dental patients. The parents are often told this, while their child is crying during the dental procedure, to try to allay their concern. Some of the pain scores for a few of the younger patients may have exhibited this phenomenon. If this effect occurred, it is possible that the effect of the DP was masked by it.
The DPs cost $2.00 each, whereas the Hurricaine Dry Handle Swabs cost $0.50 each, and the 50-g jar of Hurricaine gel costs less than $5.00. buy vardenafil online
Based on this study, the DP is not recommended for soft tissue anesthesia in children. Currently, the DP needs further clinical trials before being used in the pediatric dental population. There are too many disadvantages to using it, which include its poor bioadhesion, greater expense, and longer application time. In the clinical setting, poor bioadhesion is an important consideration because either a dental auxiliary or the dentist would need to hold the patch in place for the cases where it did not adhere. The longer application time did not make the DP’s performance superior to the performance of the topical anesthetic. Many clinicians may be looking for an alternative product that would be superior to the conventional product. A recent survey of pediatric dentists found that 71% would consider a different delivery system of topical anesthetic if it were available. However, if the alternative method has a longer application time than the conventional method, clinicians would be less interested in using it. The field of alternative local anesthetic delivery systems in dentistry should be explored to find a more ideal mechanism to provide topical anesthesia.
Blog invites submissions of review articles, reports on clinical techniques, case reports, conference summaries, and articles of opinion pertinent to the control of pain and anxiety in dentistry.