LenisUSA, LLC has a planned study for the efficacy of local anesthetic administered using the Lenis™ Needle Free Injection system. The study design is based upon the original study published by Saleh, Mechaelis, Lang and Raab which is posted below. The study will focus on how the Lenis™ Needle Free Injection system reduces patient discomfort, efficacy of local anesthetic administered by the Lenis™ Needle Free Injection system, and patient preference regarding procedures requiring either traditional injection or Lenis™ Needle Free Injection system both before and after test procedure.

Quintessenz. 53, 9, 913-920 (2002)
Anesthetic Effective Potential of a Needle-free Injection System G. Saleh, A. Michaelis, H. Lang, W. Raab, Poliklin’lk für Zahnerhaltung und Präventive Zahnheilkunde, Westdeutsche Kielerklinik, Moorenstr. C’. 40225 Düsseldorf, ghassan.saleh@uni-duesseldorf.de G. Saleh, A. Michaelis, H. Lang, W. Raab, Dutpatient Clinic for Tooth Preservation and Preventative Dental Medicine, West German Drthodontics Clinic, Moorenstr. 5, 40225 Düsseldorf, Germany, e-mail: ghassan.saleh@uniduesseldorf.de

Quintessenz. 53, 9, 913-920 (2002) Anesthetic Effective Potential of a Needle-free Injection System G. Saleh, A. Michaelis, H. Lang, W. Raab, Poliklin'lk für Zahnerhaltung und Präventive Zahnheilkunde, Westdeutsche Kielerklinik, Moorenstr. C'. 40225 Düsseldorf, ghassan.saleh@uni-duesseldorf.de G. Saleh, A. Michaelis, H. Lang, W. Raab, Dutpatient Clinic for Tooth Preservation and Preventative Dental Medicine, West German Drthodontics Clinic, Moorenstr. 5, 40225 Düsseldorf, Germany, e-mail: ghassan.saleh@uniduesseldorf. de Introduction In addition to different local anesthesia compositions, numerous local anesthesia application system; are available for the fields of dental, oral, and gnathic medicine. The fear of needle injections has been widespread since the development of the conventional syringe 140 years ago. Associated problems are numerous and primarily characterized by the defense reflex of a needle phobia. Frequently, this results in the termination of the therapy or the refusal to accept treatment with the consequence that symptoms worsen. Improved application options can significantly contribute to solving this problem. The INJEX system was developed by the company Rösch AG Medizintechnik, Berlin, in 1999. The study in hand examines this new needle-free injection system (Fig. 1) promising dosage reduced and less painful oral, dental, and gnathic work and directly compares it with conventional anesthesia systems. Material and Method The change 01 the perception threshold for electrical pulpa stimulation was determined for the comparative measurement 01 the local anesthetic effect within the scope 01 the clinical test. The pulpa was stimulated according to the noninvasive method specified by Raab9 and Raab12 The sensation of pain was triggered at the receptive organ tooth pulpa by introducing a physiological condition. This method was used to ascertain the local anesthetic effect on the pain receptors over a period of time. The compound Ultracain® D-S (Aventis, Bad Soden) was used as anesthetic in all cases. One application method for dental local infiltration anesthesia each was used with 10 test subjects ranging in age from 25 to 35 (5 male and 5 female) in random sequence on one upper center incisor during two examination days at least 1 week apart. A dose 010.6 ml is was injected each time. Several measurements were taken to determine the perception threshold for the electrical stimulation before the anesthetic was applied to establish the baseline. The program Reiz V1.02 was used to determine the subjective sensation 01 pain. This program allow5 test subjects to indicate the subjectively experienced sensation 01 pain using a joystick and monitor controls. The electrical pain threshold was determined immediately after the injection process ended and then at intervals 01 2 minutes each. Perception thresholds above 200 􀁾A corresponded with a complete elimination of pain. The following parameters were calculated to ascertain the effective profile: • Uptake time = Time from end of injection until a perception threshold 01 more than 200 µA reached Therapeutic utilization time = Duration 01 threshold increase to more than 200 µA Dissipation time = Time from drop 01 threshold below 200 µA until initial value is reached The following are the results concerning the individual measurement parameters:

Uptake time: There is a significant uptake time difference between the utilized anesthesia systems (Table 1 Fig. ) Therapeutic utilization time: There is a no utilization time difference between the utilized anesthesia systems (Table 1) Dissipation time: There is a no dissipation time difference between the utilized anesthesia systems (Table 1) Subjective painfulness during application: The factor anesthesia system proved to be not significant (Table 1) Discussion A reliable and standardized method has to be applied to provide an accurate comparison between two different anesthesia systems. Different methods are available to test for local anesthetic effect; electrical pulp stimulation was considered a suitable method 2.3.'4,16.181'. Different loeal anesthesia systems have been the subject of many studies as well. The INJEX system has been tested with patients and different painful dental procedures by Krug and Rahn'. For comparison, some of the patients were anesthetized with a conventional injection. Conditions have to be equal for both systems in order to allow a direct comparison of two systems, which is why in the study at hand INJEX and the conventional injection was used with the same test subjects and applied to the same tooth. The INJEX system and the conventional anesthesia system yielded approximately the same results. The statistical result analysis shows a significantly shorter uptake time for the INJEX system (cf. Fig.). The immediate effect of the anesthesia when using iNJEX was also noticeable clinically during the experiments. In addition, the INJEX system exhibited a tendency towards a longer therapeutic utilization time in comparison with conventional anesthesia; however, the value is without statistical significance. The statistically insignificant but allusive higher subjective sensation of pain when administering with the INJEX system confirms experiences by Krug and Raab9 . Most test subjects considered the placement of the instrument on the mucosa unpleasant. Responding to the results of our study, the manufacturer has developed a soft silicone cap (Silitops) (Fig. 14), which is applied between INJEX and mucosa, rendering the injection less unpleasant for patients. Additional research about this subject is planned. Since INJEX has to be positioned on the mucosa exactly at a right angle, the product is only applicable to specific teeth. The system is well suited for dental local anesthesia within this application scope. Although the statistical results showed significant differences only for the uptake time, the time progression of the utilization profiles seems to provide clear benefits for clinical application of the INJEX system. This is due to the reliable and rapid hysteresis as weil es the safe elimination 01 pain as early as 6 to 20 minutes after the end of the injection when using the INJEX method (cf Fig. ). The INJEX system allows for dosage-reduced anaesthetizing. This is a clear benefit especially for children due to their lower body weight and the therefore significantly lower maximum dosages, Moreover, anaesthetizing without cannula offers without doubt a phycological advantage, especially with children and overly fearful or anxious patients.