Laser irradiation has numerous favorable characteristics, such as ablation or vaporization, hemostasis, biostimulation (photobiomodulation) and microbial inhibition and destruction, which induce various beneficial therapeutic effects and biological responses. Therefore, the use of lasers is considered effective and suitable for treating a variety of inflammatory and infectious oral conditions. The CO2 , neodymium-doped yttrium-aluminium-garnet (Nd:YAG) and diode lasers have mainly been used for periodontal soft-tissue management. With development of the erbium-doped yttrium-aluminium-garnet (Er:YAG) and erbium, chromium-doped yttrium-scandium-gallium-garnet (Er,Cr:YSGG) lasers, which can be applied not only on soft tissues but also on dental hard tissues, the application of lasers dramatically expanded from periodontal soft-tissue management to hard-tissue treatment. Currently, various periodontal tissues (such as gingiva, tooth roots and bone tissue), as well as titanium implant surfaces, can be treated with lasers, and a variety of dental laser systems are being employed for the management of periodontal and peri-implant diseases. In periodontics, mechanical therapy has conventionally been the mainstream of treatment; however, complete bacterial eradication and/or optimal wound healing may not be necessarily achieved with conventional mechanical therapy alone. Consequently, in addition to chemotherapy consisting of antibiotics and anti-inflammatory agents, phototherapy using lasers and light-emitting diodes has been gradually integrated with mechanical therapy to enhance subsequent wound healing by achieving thorough debridement, decontamination and tissue stimulation. With increasing evidence of benefits, therapies with low- and high-level lasers play an important role in wound healing/tissue regeneration in the treatment of periodontal and peri-implant diseases. This article discusses the outcomes of laser therapy in soft-tissue management, periodontal nonsurgical and surgical treatment, osseous surgery and peri-implant treatment, focusing on postoperative wound healing of periodontal and peri-implant tissues, based on scientific evidence from currently available basic and clinical studies, as well as on case reports.

Several studies have suggested the jaw-muscle spindle as the receptor responsible for regulating and maintaining the occlusal vertical dimension (OVD). However, to challenge this assumption, we hypothesized that long-term changes in OVD could affect the sensory inputs from jaw-muscle spindles. In this study, we investigated changes in masseter muscle spindle function under an increased OVD (iOVD) condition. Responses of primary and secondary endings of masseter muscle spindles to cyclic sinusoidal stretches were investigated. Twenty barbiturate-anesthetized female Wistar rats were divided into control and iOVD groups. Rats in the iOVD group received a 2.0-mm composite resin build-up to the maxillary molars. After iOVD, masseter muscle spindle sensitivity gradually decreased. Primary and secondary spindle endings were affected differently. We conclude that iOVD caused reduction in masseter muscle spindle sensitivity. This result suggests that peripheral sensory plasticity may occur following changes in OVD. Such changes may provide a basis for physiological adaptation to clinical occlusal adjustments.

These findings suggest that optimization of the chewing pattern and acquisition of appropriate masticatory function is impeded by malocclusion. Altered mechanical loading to the mandible may cause significant reduction of condylar width and mandibular BMD.

SUMMARY The membrane properties of isolated frog parathyroid cells were studied using perforated and conventional whole-cell patch-clamp techniques. Frog parathyroid cells displayed transient inward currents in response to depolarizing pulses from a holding potential of –84 mV. We analyzed the biophysical properties of the inward currents. The inward currents disappeared by the replacement of external Na+ with NMDG+ and were reversibly inhibited by 3 μmol l–1 TTX, indicating that the currents occur through the TTX-sensitive voltage-gated Na+channels. Current density elicited by a voltage step from –84 mV to–24 mV was –80 pA pF–1 in perforated mode and–55 pA pF–1 in conventional mode. Current density was decreased to –12 pA pF–1 by internal GTPγS (0.5 mmol l–1), but not affected by internal GDPβS (1 mmol l-1). The voltage of half-maximum (V1/2)activation was –46 mV in both perforated and conventional modes. V1/2 of inactivation was –80 mV in perforated mode and –86 mV in conventional mode. Internal GTPγS (0.5 mmol l–1) shifted the V1/2 for activation to–36 mV and for inactivation to –98 mV. A putative endocannabinoid,2-arachidonoylglycerol ether (2-AG ether, 50 μmol l–1) and a cannabinomimetic aminoalkylindole, WIN 55,212-2 (10 μmol l–1) also greatly reduced the Na+ current and shifted the V1/2 for activation and inactivation. The results suggest that the Na+ currents in frog parathyroid cells can be modulated by cannabinoids via a G protein-dependent mechanism.