Effects of different photobiomodulation dosimetries on temporomandibular dysfunction: a randomized, double-blind, placebo-controlled clinical trial.

Changes involving temporomandibular joint, masticatory musculature, and associated structures characterize temporomandibular dysfunction (TMD). The analgesic and anti-inflammatory effect produced by photobiomodulation has contributed to pain relief and functional improvement. However, the parameters to be used have not yet been well established. The aim of this study is to compare the efficacy of three different photobiomodulation dosimetries in the treatment of patients with TMD. A randomized, double-blind, placebo-controlled clinical trial with 44 subjects divided into the groups 8 J/cm2 (n = 11), 60 J/cm2 (n = 11), 105 J/cm2 (n = 11), and control (n = 11). Pain, symptom severity, and joint mobility were evaluated before and after a ten-session protocol of photobiomodulation with AlGaAs laser (830 nm), at a power density of 30 mW/cm2. The mouth opening increased in the 8-J/cm2 group from 10.49 ± 4.68 to 15.40 ± 6.43 degrees, and in the right protrusion from 9.80 ± 4.2 to 12.56 ± 5.40 degrees after the intervention protocol (p < 0.05). All groups significantly decreased pain (p < 0.05). 830-nm laser photobiomodulation was effective in reducing TMD pain and symptoms at all doses tested. Only the doses of 8 J/cm2 were effective regarding maximal opening and protrusion of the mandible.

Degree of conversion and hardness of an orthodontic resin cured with a light-emitting diode and a quartz-tungsten-halogen light.

The purpose of this study was to assess the influence of two light units, a quartz-tungsten-halogen (QTH) and a light-emitting diode (LED), on the hardness and degree of conversion of an orthodontic composite resin. Sixty specimen disks were prepared from Transbond XT composite resin (3M Unitek) and light cured for 10, 20, and 30 seconds with a QTH (Curing Light XL 3000, 3M Unitek) or a LED (Ortholux, 3M Unitek) light-curing unit for 5, 10, and 15 seconds. Composite resin polymerization was evaluated by Fourier-transform infrared (FTIR) spectrophotometry and Knoop hardness number (KHN). The results were statistically analysed using analysis of variance and Tukey's multiple comparisons test (alpha = 0.05). The highest KHN was obtained with the QTH at 30 (25.19 KHN) and 20 (24.01) seconds, which did not differ statistically, and in the LED 15 second (21.86) group. The QTH 10 second group (20.53) did not differ statistically from the QTH 20 second or the LED 5 (19.96) and 15, or 10 second (18.95) groups. According to FTIR, there was no statistical difference for the degree of conversion among the groups, QTH 10 (43.42 per cent), QTH 20 (46.12 per cent), QTH 30 (45.30 per cent), LED 10 (47.02 per cent), or LED 15 (47.24 per cent) seconds. The lowest degree of conversion was obtained for the LED 5 second group (38.97 per cent), which did not differ statistically from the QTH 10 second group. Light curing with the LED resulted in a reduction of 50 per cent in the time recommended for use of the QTH light with the composite resin, Transbond XT.

Presença de dentes permanentes irrompidos em escolares da região metropolitana de Porto Alegre / Presence of permanent erupted teeth in scholars of metropolitan area of Porto Alegre

Foi realizada uma pesquisa de campo em duas escolas da rede pública estadual de Porto Alegre, com a finalidade de verificar a presença de dentes permanentes irrompidos em crianças com faixa etária entre seis a dez anos. Foram examinadas 327 crianças, considerando as variáveis de idade, sexo e raça. Não foi observada diferença significativa para a época de erupção para as variáveis de raça e sexo. Foi observado que aos seis anos de idade uma porcentagem maior de incisivos inferiores (78,7%) irrompeu antes que os primeiros molaresinferiores (75,9%), assim como a erupção na arcada inferior antecedeu a da arcada superior. O trabalho teve como referência didática uma ampla literatura sobre os diferentes tópicosrelacionados ao processo evolutivo da dentição.

A survey was performed in two public schools of Porto Alegre, with the purpose of demonstrate the presence of erupted pennanent teeth in children with age ranging from 6 to 1 O years old. The sample consisted of 327 patients and the variables examined were age, sex and race. In the 6 year old group, the lowers incisors (78,7%) erupted earlier than the first molars(75,9%) and the teeth on the lower arch erupted before the teeth on upper arch. It was not observed a significant difference (p<0,05) in the time of eruption of the teeth for the variablessex and race. A literature review of teeth evolution process and related factors were alço described.