Photobiomodulation (PBM) therapy is a promising approach for the management of inflammatory conditions and autoimmune lesions, such as oral lichen planus (OLP). The aim of this retrospective study was to assess the effectiveness of PBM in the management of painful and erosive/ulcerative OLP and to compare it with the standard of care that is the topical application of corticosteroids. 96 patients were included with erosive and painful OLP. 48 patients received PBM therapy and 48 received corticosteroids. Data was collected retrospectively on pain using the visual analogue scale; clinical aspects of lesions were assessed with the REU score, and the recurrence rate was noted. One session of PBM therapy with a helium-neon red light (635 nm) was carried out every 48 h for 6 weeks. Treatments were mainly made in contact mode, using a fiber with a diameter of 600 µm (0.6 mm). The output power of the laser beam was calibrated by a power meter. A delivered power of 0.1 W was used for 40 s in a continuous wave (CW), corresponding to a delivered energy of 4 J. The delivered energy density related to the fiber diameter was 1415 J/cm2. Each treated point was considered as 1 cm2 of diameter. PBM therapy within these parameters was carried out on each point until the totality of the lesion was covered, including the non-erosive OLP area. Furthermore, healthy mucosa within 5 mm of the lesion was also irradiated with the same conditions. This PBM treatment was performed during 6 consecutive weeks. The topical corticosteroid treatment consisted of cortisone application to cover the OLP 3 times/day for 6 weeks. Follow-up was made at 6 weeks and at 3, 6 and 12 months. After 6 weeks, both groups showed complete absence of pain, and a complete disappearance of ulcerative/erosive areas. No significant difference was found for both groups concerning the recurrence rate of erosive OLP during the follow-up period; values were 0% at 6 weeks for both groups and 79% and 87.5% for the corticosteroid and PBM group, respectively, at 12 months of follow-up. PBM is effective for managing OLP and is significantly similar to topical corticosteroids without any need for the use of medication and with no reported side effects.

Introduction: An important and non-adapted delivered energy of Er:YAG laser can eliminate the total thickness of root cementum during root planing. Conversely, the preservation of a partial layer of cementum covering the roots is vital for any periodontal ligament regeneration. Thus, the assessment of the cementum ablation depth produced by each energy density of Er:YAG laser is essential before considering its use for the periodontal planing and treatment of the cementum and root surfaces. Aim of the study: Assessment of the cementum ablation depth at different energy densities of the Er:YAG laser is the aim of this study. Materials and methods: A total of 48 human caries free molars were collected and used in this study. Areas to be irradiated were delimited by two longitudinal grooves (0.5 mm depth). Roots were divided randomly into four groups (4 × n = 12). An Er:YAG laser (2.94 µm) was used with a side-firing tip (R600T) with a 600 µm diameter and a frequency of 20 Hz combined with a cooling system of air 6 mL/min and water 4 mL/min. We used a super short pulse mode (SSP: pulse duration: 50 μs). We used a single irradiation passage backward from apex to cervical parts at 1 mm/s with a slight contact and at an angle of 15° to 30° between the tip and the root surface. Different energies were selected: 30 mJ, 40 mJ, 50 mJ, and 60 mJ. Results: Microscopic observations showed that the average of the ablation depth increased with the increase of the delivered energy from 30 mJ to 60 mJ. Mean values of the ablation depths were respectively as follows: 43.75 ± 4.89 µm for the energy of 30 mJ, 50.05 ± 3.72 µm for 40 mJ, 65.56 ± 10.35 µm for 50 mJ, and 74.80 ± 15.23 µm for 60 mJ. A statistically significant difference existed between the ablation depth of all groups. Conclusion: Based on our results, the depth of cementum debridement is related to the level of the delivered energy. The lowest energy levels (30 mJ and 40 mJ) can ablate the root cementum surface for a variable depth from 43.75 ± 4.89 μm to 50.05 ± 3.72 μm.

Direct pulp capping (DPC) is reliable in pulp exposure management. Objective: This study aimed to assess the success rate of DPC materials and different laser protocols. The included procedures were CO2 laser (n = 1147), Er: YAG laser (n = 69), and 980 nm diode laser (n = 124), on the one hand, and Ca (OH)2 (n = 376) and bioactive tricalcium silicate paste, on the other (n = 279). Materials and methods: Data from 1995 DPC cases were included. For laser groups, irradiation was used to coagulate the pulp exposure followed by Ca (OH)2 placement. Data with follow-up at 12, 24, and 36 months post-treatment were included. The irradiation parameters for the CO2 laser were as follows: energy density per pulse of 141 J/cm², 1 W power, 0.3 mm beam diameter, 100 ms pulse duration, and 1 Hz, and a series of five pulses maximum were delivered during 5 s. For the 980 diode lasers: 1.5 W power, continuous wave (CW), 400 μm fiber diameter, contact mode, 190.98 W/cm2 power density, and total delivered energy density of 2387 J/cm2. For the Er: YAG laser: 0.5 W output power, 9.95 J/cm2 energy density, a beam diameter of 0.8 mm, 300 µsec pulse duration, 10 Hz, non-contact mode, irradiation with air without water spray, and an average irradiation time of 8–10 s. Results: At the 3-year follow-up, the success percentages were as follows: CO2 (88.01%) > Ca (OH)2 (75.72%) > diode (70.01%) > Er: YAG (54.55%) > bioactive tricalcium silicate paste (51.1%). The timing of permanent filling (immediate or delayed), patient age, size of pulp exposure, tooth type, and exposure etiology significantly affected the success rate. Patients aged ≤ 35 years presented higher success (70.91%) compared to those ≥ 36 years (61.2%). Immediate permanent fillings increase the success rate (71.41%) compared to delayed permanent fillings (65.93%). Exposure in molars and premolars significantly lowers the success rate (60.3%) compared to canines and incisors (72.1%). Idiopathic pulp exposure presented higher success (72.58%) compared to caries-related causes (63.7%). Conclusion: The highest success rate was in the CO2 laser group followed by the diode and Ca (OH)2, Er: YAG, and bioactive tricalcium silicate material (biodentine) groups. The age factor, filling timing, size of exposure, tooth type, and exposure etiology can significantly affect the success rate of DPC.