Evaluation of selective caries removal in deciduous teeth by a fluorescence feedback-controlled Er:YAG laser in vivo

Abstract

This study investigated the ability and efficacy of an Er:YAG laser with a fluorescence feedback system for caries removal in deciduous teeth. Seventy-nine carious lesions were excavated using a fluorescence-controlled Er:YAG laser. Endpoint of treatment was defined by emission of fluorescence from the dentine surface below the pre-selected threshold level of 7 units and the subsequent termination of Er:YAG laser radiation. Dentine samples were obtained from the cavity floor, and viable counts of both Streptococcus mutans and Lactobacilli, expressed as colony forming units (log CFU), were evaluated. Preparation time was recorded to assess efficacy of the treatment procedure. S. mutans and/or Lactobacilli were found in 25 out of 79 lesions. Regarding the counts for S. mutans and Lactobacilli, the median log CFU was 0 (min, 0; max, 5.5) and 0 (min, 0; max, 6), respectively, with 2.4% of all samples yielding more than 100 CFU S. mutans and 4.8% yielding more than 100 CFU Lactobacilli. In 8 out of 79 cases, laser excavated cavities were not judged being caries-free using the conventional tactile criterion for assessing caries tissue. Focussing on these teeth, the median log CFU was 0 (min, 0; max, 0.5) for S. mutans and 0 (min, 0; max, 1.6) for Lactobacilli. The mean time for treatment was 2.3+/-1.2 min. Of the children, 93.8% rated the laser treatment to be comfortable. The study indicates that the fluorescence feedback-controlled Er:YAG laser might be an appropriate device for caries removal in children using the suggested threshold level of 7 units.

Deri̇n Denti̇n Çürükleri̇ni̇n Tedavi̇si̇nde Alternati̇f Yeni̇ Yöntemler

“…Dokuya temas etmeden çalıĢma zorunluluğunun getirdiği kontrol kaybı, floresans geribildirim özelliği ile kombine edilmiĢ Er:YAG lazerler ve Er, Cr:YSGG lazerlere eklenen sesli uyarı sistemi ile giderilmeye çalıĢılmıĢtır. [51][52][53] Çürüğü uzaklaĢtırmak amacıyla kullanılan CO 2 , Nd:YAG ve Erbium lazerler sağlıklı doku ile çürük dokunun ayırt edilmesini sağlarken, enfekte ve etkilenmiĢ dentin ayrımını sağlayamamaktadır. Bu nedenle daha selektif yaklaĢımlar için gerekli dalga boyları ve lazer tipleri geliĢtirilmeye çalıĢılmaktadır.…”

Laser Technology for Caries Removal

“…However, the adjustment of laser energy density in commercial equipments is sometimes difficult to promote the selective ablation of infected dentin and in order to preserve the affected dentin, and the clinical results still depend on the experience and knowledge of the professional, added to the use of manual instruments for correct diagnosis of remaining tissue. In fact, clinical trials report the well acceptance of patients (Dommisch et al, 2008;Krause et al, 2008), the maintenance of pulp vitality and marginal seal, the good quality of restorations and the absence of secondary caries even after two years (Yazici et al, 2010). Also, it is reported that these lasers can fulfill the requirements of Minimal Invasive Dentistry, due to the possibility of conservation of the sound tissue structure during caries removal and to the possibility of surface decontamination of affected dentin (Kornblit et al, 2008).…”

“…To determine an end point for caries removal, there are some equipments that associate Er:YAG laser irradiation to the diagnosis by laser fluorescence (Dommisch et al, 2008;Eberhard et al, 2008;Jepsen et al, 2008;Krause et al, 2008;). The essential principle of this application is that the fluorescence of sound tissue differs from the fluorescence of carious tissue due to the variation in chemical composition, such as the presence of proteins, bacteria and other contents.…”

“…In this equipment, the fluorescence is induced by red laser that emits at the wavelength of 655 nm, and the Er:YAG laser is turned off when significant changes on fluorescence are detected during caries removal, established by a cut-off value that indicates that all decayed tissue was removed. Some in vitro Jepsen et al, 2008) and in vivo (Dommisch et al, 2008;Krause et al, 2008) studies showed the feasibility of this equipment; however, there is no consensus about the correct values of cutoff in different clinical conditions. Also, it must be emphasized that there are limitations of this technique mainly in dentin Krause et al, 2008), when falsepositive can be reported due to the presence of pigments in affected or tertiary dentin, for instance, which should not be removed.…”

“…Some in vitro Jepsen et al, 2008) and in vivo (Dommisch et al, 2008;Krause et al, 2008) studies showed the feasibility of this equipment; however, there is no consensus about the correct values of cutoff in different clinical conditions. Also, it must be emphasized that there are limitations of this technique mainly in dentin Krause et al, 2008), when falsepositive can be reported due to the presence of pigments in affected or tertiary dentin, for instance, which should not be removed. In this way, the association of manual instruments and is still necessary to assure a safe and correct clinical removal of dental caries.…”