Sara Tavakolizadeh

Objectives: Temporomandibular disorder (TMD) encompasses various clinical issues affecting the temporomandibular joint, masticatory muscles, and surrounding structures. Common symptoms include pain, joint and muscle tenderness, and limited jaw movement. Diverse treatment options have been utilized to manage TMD. However, evidence of the combined modality treatment approach is scarce. This pilot trial aimed to evaluate the effectiveness of combining stabilization splint therapy (SST) with low‐level laser therapy (LLLT) in managing TMD.Material and Methods: This pilot parallel randomized clinical trial included 30 patients with TMD. Patients were randomly allocated equally into three treatment groups: SST, LLLT, and combined treatment (CT). Outcomes, including pain and functional limitations, were measured at baseline, 1, 2, 3, and 4 weeks after the start of each treatment.Results: CT was significantly more effective in reducing pain in patients with TMD compared to LLLT and SST. Although patients in the LLLT group reported significantly reduced pain, they still had higher pain scores compared to the SST group at certain time points, indicating that LLLT was not as effective as SST. Most functional limitations were improved over time, more consistently within the CT group, but without significant differences between the three groups. Patients were more satisfied with CT compared to LLLT and SST.Conclusions: The superior results of the CT group over the SST and LLLT groups were evident in this pilot trial's outcomes. The combined modality treatment approach seems to yield the greatest improvement for TMD patients.

Background. In implant-supported overdentures increase in the number of implants improves the retention and stability of the overdentures. A direct correlation exists between prosthesis retention and patient satisfaction. Therefore, this experimental study assessed the effect of attachment type and implant position on the retention of mandibular implant-supported overdentures. Methods. A transparent acrylic resin model of the mandible was fabricated, and dental implants were positioned at the first molar area (position 6), between the lateral incisor and canine teeth (positions B and D), and first premolars (positions A and E) bilaterally. Novaloc attachments (strong, medium, and light retentive caps) were used with ABDE, 6AE6, and 6BD6 implant positions. A Dolder bar attachment was also used with the ABDE implant position. Overdenture retention was measured under vertical loading, and the maximum dislodging force (MDF) was recorded. Data were analyzed by two-way and one-way ANOVA and post hoc Tukey tests (α=0.05). Results. The effects of attachment type and implant position [except for ABDE and 6AE6 with light retention insert (P=0.49), and 6AE6 and 6BD6 with strong retention insert (P=0.48)], and their interaction effect were significant on MDF (P<0.01). The highest retention was recorded for bar attachment (65.15 N), with the lowest for Novaloc attachment with light retention insert at ABDE implant position (11.97 N). Conclusion. With Novaloc attachments, minimum retention was recorded in ABDE, and maximum retention was recorded in the 6BD6 implant position due to the increased distance between attachments. The strong insert showed the highest retention value, which confirmed the manufacturer’s claim. Maximum retention was recorded with the bar and clip attachment.

Purpose: The purpose of this in vitro study was to assess the color match of ultra‐translucency multilayer zirconia restorations with different designs and backgrounds.Materials and methods: Thirty ultra‐translucency multilayer zirconia crown specimens were made in VITA classical shade B2 for a prepared maxillary central incisor. The specimens were divided into three groups based on the restoration design: veneered zirconia with a trestle design (VZT), veneered zirconia with a dentin core design (VZD), and full‐contour zirconia (FCZ). In the groups VZT and VZD, the zirconia specimens were layered with a feldspathic veneering ceramic. The specimens were seated on five different backgrounds: shade B2 composite resin, shade B2 zirconia, copper‐colored metal alloy, silver‐colored metal alloy, and the prepared central incisor. CIELab values of the labial middle sections of the crown specimens were measured with a spectrophotometer. Color differences between the specimens and a shade B2 VITA classical tab (as a control) were calculated from the ΔE^*_ab formula and compared with an acceptability threshold (ΔE^*_ab = 3.7) to be clinically explicated.Results: Mean ΔE^*_ab values ranged between 1.17 and 8.48. The restoration design, the background type, and their interaction affected the ΔE^*_ab (p < 0.001). The mean ΔE^*_ab values for VZT with all backgrounds and for VZD with the silver‐colored metal background were greater than the threshold (p < 0.001), whereas the mean ΔE^*_ab values for VZD with the other backgrounds and FCZ with all backgrounds were less than the threshold (p = 1).Conclusions: Restoration design and background type affected the color match of ultra‐translucency multilayer zirconia restorations. VZT restorations on all backgrounds and VZD restorations on a silver‐colored metal background showed color mismatches. However, VZD restorations on the other backgrounds and FCZ restorations on all backgrounds demonstrated color matches.

The dental implant is one of the appropriate instances of the different dental materials and their application, which is the combined procedure of technology and science in physics, biomechanics, and surface chemistry from macroscale to nanoscale surface engineering and manufactured technologies. In recent decades, biomaterials in implant therapy promote bone response and biomechanical ability, which is long-term from surgical equipment to final prosthetic restoration. Biomaterials have a crucial role in rehabilitating the damaged structure of the tooth and supplying acceptable outcomes correlated with clinical performance. There are some challenges in implantation such as bleeding, mobility, peri-implant infections, and the solution associated with modern strategies which are regarded to biomaterials. Various materials have been known as promising candidates for coatings of dental implants which contain polyhydroxyalkanoates, calcium phosphate, carbon, bisphosphonates, hydroxyapatite, bone stimulating factors, bioactive glass, bioactive ceramics, collagen, chitosan, metal and their alloys, fluoride, and titanium/titanium nitride. It is pivotal that biomaterials should be biodegradable; for example, polyhydroxyalkanoates are biodegradable; also, they do not have bad effects on tissues and cells. Despite this, biomaterials have important roles in prosthetic conditions such as dental pulp regeneration, the healing process, and antibacterial and anti-inflammatory effects. In this review study, the role of biocompatible materials in dental implants is investigated in in vitro and in vivo studies.

Introduction: This study investigated the effect of various laser powers on the shear bond strength (SBS) of resin cement to the zirconia surface. Methods: Seventy-five zirconia disks were prepared and assigned to five groups including no surface treatment (control group), sandblasting with 50 µ Al2 O3 particles (second group), and Nd:YAG laser treatments with 2 W, 2.5 W and 3 W powers respectively (third, fourth and fifth groups). Afterwards, composite resin cylinders were cemented on zirconia disks using dual-curing resin cement. Before thermocycling (2000 cycles, 5-55°C), all samples were placed in distilled water at 37°C for 24 hours. Using a universal testing machine at the crosshead speed of 0.5 mm/min, the SBS was examined. Also, using a stereomicroscope, the failure type was determined. Data analyses were performed using Welch and Games-Howell tests (P< 0.05). Results: The mean bond strength difference between the control group and the other groups was significant. The respective bond strength from the highest to the lowest was observed in the sandblast group, the laser group with 2.5 W power, the laser group with 3 W power, the laser group with 2 W power, and finally the control group. However, no significant difference was observed between different laser groups (P< 0.05). Also, there was no significant difference between the sandblast and laser groups with 2.5 W and 3 W power (P< 0.05). Most of the failures in the sandblasting and laser groups with powers of 2.5 W and 3 W were mixed, but in the control and 2 W laser groups, most of the failures were of adhesive nature. Conclusion: The highest bond strength was achieved by sandblasting with Al2 O3 particles and then using an Nd: YAG laser with a power of 2.5 W.