## 4 Discussion
Some studies have shown that modulated polymerisation modes, especially soft start, result in better polymerisation dynamics and consequently lower shrinkage [53]. Final high irradiance would complete polymerisation, leading to a convenient degree of conversion and reaching the desired physical and mechanical properties [40]. According to [PERSON] et al., a high degree of conversion (DC) of composite polymerisation is a prerequisite for obtaining the optimal physical and mechanical properties, biocompatibility, and improved success of composite restoration [54]. Many clinical studies indicate the advantage of the soft start mode over others; however, this is true only at a distance of 0 mm. Unfortunately, 0 mm distance is seldom possible in clinical conditions, so to maintain the mentioned advantages of this mode, the exposure time should be significantly extended, even up to 1 min [40; 55]. The slight differences in lamp power observed in standard and pulse modes correspond to the results of [PERSON] et al., who examined the physicochemical properties of composites polymerised in various ways. The characteristics of the polymer exposed to standard and pulse modes were very similar [56]. The differences in modulated polymerisation modes are very subtle and difficult to detect, especially in clinical conditions, and require further analysis. As already mentioned, proper polymerisation is directly related to the degree of composite conversion. The authors suspect that in the case of increasing the distance in the pulsating and soft start modes, the degree of conversion may not even reach 50%. The next step of the research will be to combine the exposure modes, increasing the distance, and a more advanced (using a Raman microscope) measurement of the degree of conversion of the polymerised material to prove the thesis even more precisely. Dental composite is a highly aesthetic material for tooth restoration, but it causes dentists many problems and generates numerous complications [57]. Such many articles on composite complications encourage authors to search for new teaching methods and create algorithms for polymerisation procedures. Introducing dental radiometers to assess the light irradiance into everyday practice could be helpful for clinicians to evaluate and control the ability of LCUs to polymerise [14; 35]. This would have a real impact on the quality and stability of fillings and, thus, the effectiveness of treatment. One limitation of this study is that the Bluephase Meter II was brand new. However, the manufacturer guarantees proper device operation for up to 3 years as well as high measuring accuracy with a tolerance of only \(\pm\) 10% compared to the measurement with an integrating sphere. Moreover, the LCUs were not new, but they were undamaged and in good working condition; they were recharged after every five exposures. Thus, they represented what may be found in many dental offices. The positioning of the lamp in the holder relative to the radiometer also may be a limitation. In the next analyses, it is planned to use an optical bench to fasten the correct position. This article provides dental clinicians with a portion of knowledge and simple clinical tips that can be used in every dental office during the most performed procedure--direct tooth restoration using a composite material.