Non-interventional study to collect data for the application of lidocaine gel 2% during scaling and root planing and professional mechanical plaque removal

Severe periodontitis was the sixth most prevalent disease condition in the world in 2010, affecting 743 million people worldwide [1]. Even though the results of the Fifth German Oral Health Study [2] showed a significant decrease in periodontal disease in Germany, it is still widespread: 51.6% of the young adults (aged 35–44) and 64.6% of the younger elderly (aged 65 to 74) suffered from periodontitis. The Studies of Health in Pomerania (SHIP) also revealed an improvement of periodontal conditions together with an increasing number of present teeth, thereby implying a growing need for treatment of moderately diseased teeth [3]. Consensus reports of the 11th European Workshop on Periodontology have affirmed the necessity for supportive periodontal therapy regimens for periodontitis patients [4, 5]. The success of preventive measures and periodontal therapy depends on patient compliance among other factors.

Although there is usually no anesthesia given for PMPR, many patients prefer some kind of anesthesia even during supragingival tooth cleaning. Up to 30% of the patients undergoing PMPR require pain control [6]. Injection anesthesia is still the most frequent choice for non-surgical periodontal treatment. However, many patients are afraid of the pain associated with dental injections and do not like the prolonged numbness [7]. This might lead to a reduced compliance in periodontal maintenance, especially for pain-sensitive patients or patients with needle phobia, also called trypanophobia [8]. One of the results from an observational study in China was that comfort during treatment is an important factor influencing compliance of patients with chronic periodontitis [9].

Various studies have demonstrated that topical anesthetic gels are a well-accepted possible alternative to either injection anesthetics [10, 11] or placebo [12, 13] for patients who need pain control during scaling and root planing (SRP).

Therefore, the aim of this non-interventional observational study was to collect data, under real-life practice circumstances, about the use of lidocaine gel 2% (Dynexan Mundgel®, LG) as a topical anesthetic for non-surgical treatment of periodontal disease and for PMPR in dental practices all over Germany.

A major problem of studies assessing pain or pain levels is the fact that pain perception is subjective and may vary considerably between individuals. Aches and pains are considered complex products of a variety of physical, cognitive, and emotional factors. In a clinical setting as the one assessed here, the operator is an additional important factor, which may act as confounder, since dexterity and operation skills are important factors influencing the pain level perceived by the patient. Data indicates that correct communication and explanation about the topic of pain prior to therapy may lower the need for anesthetics [17]. These highly person-related factors are difficult to control even in a prospective randomized and controlled study setting. As opposed to randomized clinical trials that operate in an idealized environment with a pre-selected homogenous patient population, observational studies allow the collection of data from routine conditions in daily clinical practice [18, 19]. The aim of this observational study was to collect true-to-life data about the use of lidocaine gel 2% as a topical anesthetic in dental practices. The effect of the same anesthetic gel on pain sensitivity and wound healing, when applied following SRP, has been tested in a previous study [20]. In most cases observed in this study, the anesthetic gel was used for scaling and root planing and professional mechanical plaque removal and the overall acceptance by all patients was very high: 92% of the patients would choose LG for a similar future treatment. This clearly demonstrates the patients wish for some form of anesthesia not only for SRP but also for PMPR. A total of 38% of the patients reported no pain during treatment and another 47% were mostly pain free. Together with another 10% reporting being sufficiently pain free, about 95% of all patients were sufficiently anesthetized with LG. The average score given by the patients was 1.82 thus indicating a “mostly pain free” therapy. As expected, the pain perceived by patients undergoing SRP compared to that of patients receiving PMPR was slightly higher and so was the need for a re-application of LG with 26% for SRP and 15% for PMPR patients. However, the number of patients requiring re-application was considerably lower than that found in a randomized clinical trial (RCT) comparing injection anesthesia with two different anesthetic gels and placebo [21], where almost half of the patients needed re-application of the lidocaine/prilocaine gel for effective pain control during SRP. Nevertheless, the data collected in the current study stems from an observational design with a different investigational product and may therefore not be fully comparable to the results of Antoniazzi et al. [21].

If the choice for LG in a future treatment is regarded separately, the preference among the patients who received SRP is even higher with 97% than for the patients who received PMPR with 92%. The need for re-application seems to have no influence on the acceptance by the patients. This is consistent with studies comparing topical anesthetic gels with injection anesthesia which show a high preference for anesthetic gels by up to 80% of the patients [22, 23]. In an observational study, 72.4% of the patients preferred a lidocaine/prilocaine gel for SRP even though the treatment of deeper pockets caused increasing procedural pain levels [24]. Most likely, a certain amount of pain is accepted if an injection resulting in pain from the needle penetration as well as sustained numbness can be avoided.

The anesthetic depth that can be achieved with LG is sufficient for most patients, which can also be seen from the small percentage of patients, 5% for SRP versus 3% for PMPR, who actually needed “rescue anesthesia”. The evaluation of LG by the treating personnel with regard to the efficacy (onset and duration), handling, and patient treatability resulted in mostly “very good” and “good” grades, also demonstrating a very high acceptance. Whether freedom of pain is achieved by the use of LG or may simply be explained by the fact that the patient is less sensitive to pain cannot be assessed in an observational study. In addition, it can be assumed that subgingival debridement is perceived as being more unpleasant than supragingival cleaning. Another point to discuss is the impact of the method of instrumentation on perceived pain. Data indicates that patients may perceive hand instrumentation as being more painful than ultrasonic scaling even when topical anesthetics are applied [25]. However, data generated in a dental practice setting assessing the pain level during a routine scaling and polishing procedure revealed that without anesthesia, patients perceive curettes as less painful than ultrasonics [26]. It would have been interesting to stratify our data by instrumentation technique used; however, it was not documented, what type of instrument was used for debridement.

Only one adverse effect was observed in this non-interventional study, demonstrating a high degree of safety for LG. One patient suffered from a transitional numb tongue. It can only be speculated whether some gel was accidentally applied to the tongue or the patient moved his tongue to the gel applied to the sulcus. According to the PSR values recorded, 79% of the PMPR patients suffered from moderate or severe periodontitis, indicating that the PMPR performed could rather be classified as periodontal maintenance therapy.

Lidocaine gel 2% offers a safe, effective, and highly accepted method of achieving a pain-free treatment for periodontal and maintenance patients.