# Should the Application of Diode Laser Completely Replace Conventional Pulpotomy of Primary Tenth?
## 2 Materials and Methods  
### Study Design  
The participants of this prospective study were patients of the Department of Pediatric and Preventive Dentistry, School of Dental Medicine, University of Zagreb, who enrolled in the study according to the indications. Before patient enrollment sample size analysis was determined. Considering the required sample size of 124 subjects, and possible exclusions and withdrawals of subjects, 140 patients were enrolled in the study. The study protocol consisted of 2 allocations (pulpotomy treatment and final restoration) and 3 follow-up periods--after 6, 12, and 24 months. Subsequently, due to drop-outs, the data of 120 respondents were complete and ready for analysis (Figure 1). Although the analysis included a smaller sample than determined by the sample size analysis, the post-hoc power analysis confirmed sufficient power (83%). The research included 120 subjects (M:57, F:63) aged 5-8 years. Parents received a written explanation of the entire procedure, while written consent was obtained. Only respondents whose parents signed the informed consent were included in the research. The research was approved by the Ethics Committee of the School of Dental Medicine Zagreb (number: 05-PA-15-10/2017) in accordance with the ethical standards of the Declaration of Helsinki. It included patients with one or more deep curious lesions on primary molars with unresolved roots and feasible restorative treatment who did not mention the appearance of spontaneous or permanent pain in the anamnesis and in which it is possible to achieve hemostasis with a sterile cotton swab within 5 min after amputation. Patients with the following characteristics: the presence of swelling or fistula, insensitivity to percussion and palpation, pathological mobility, allergy to some of the ingredients of the used materials, children with special needs, and the existence of systemic disease that would further impair oral health were excluded from this research. Before the start of treatment, a clinical examination of the affected tooth, its surrounding structures, and the condition of the tooth root and periapical tissue were performed on an intraoral roentgenogram where radiographic evidence of pulp or periadicular pathosis and calcification in the pulp chamber were additional criteria for the exclusion of participants. Patients were then  
Figure 1: Sample size and the study protocol. randomly divided into two groups. In the first group, 60 subjects underwent pulotomy using the traditional method with a sterile steel drill (3M/ESPE, Seefeld, Germany) or excavator (LM-Dental, Planmeca, Parainen, Finland) under local anesthesia using Ubistesin forte (3M/ESPE, Seefeld, Germany). In the second group, devitalization was performed using a diode laser with a wavelength of 980 nm LaserHF Comfort (Hager & Werken, Duisburg, Germany). A 3 W laser beam was used continuously through an optical fibre with a diameter of 320 m in contact with the pulp tissue for two and a half minutes. In both groups, the Biodentine (Septodont, Saint-Maur-des-Fosses, France) was used to cover the root part of the pulp. Each group was further randomly divided into two subgroups according to the type of material for the definitive filling. In the first subgroup, glass ionomer Fuji IX (GC, Tokyo, Japan) was used as a material for permanent fillings, while in the second, the material of choice was Tetric Ceram composite (Ivoclar Vivadent, Schaan, Liechtenstein). Follow-up examinations were carried out 6 months, 12 months, and 24 months after the pulotomy. During the control examinations, a clinical examination and X-ray analysis using the GendexTMGXS-700 TM sensor (Gendex Dental Systems, Hatfield, PA, USA) of the treated teeth was carried out in the same way as before the procedure. The clinical examination included: intraoral and extraoral visual examination, percussion, and palpation.