Cracks adversely affect the prognosis and survival of the teeth. Thus, the possibility of presence of crack should be considered after endodontic treatment and before the initiation of periodontal/prosthetic treatments. Attempts must be made to restore cracked teeth with efficient restorative materials to increase their survival and prevent additional costs.

Objectives: This study aimed to assess the effect of application of two types of zirconia primers on repair bond strength of composite to zirconia ceramic. Materials and Methods: In this in vitro, experimental study, 60 zirconia blocks were divided into five groups and subjected to the application of Z-Prime Plus (ZPP), Monobond Plus (MBP), Porcelain Bonding Resin (PBR), ZPP followed by PBR (ZPP+PBR) and MBP followed by PBR (MBP+PBR). They were then bonded to Z100 composite. The samples were then immersed in water at 37°C for 24 hours, thermocycled for 1000 cycles between 5-55°C and subjected to shear bond strength (SBS) test. The mode of failure was determined under a stereomicroscope and a scanning electron microscope (SEM). Results: The mean bond strength was the highest in ZPP+PBR group followed by MBP+PBR, ZPP, PBR and MBP group (22.29±8.86, 15.75±2.81, 12.02±3.24, 3.60±2.92 and 2.92±1.78 MPa, respectively). The effects of type of zirconia primer and use/no use of PBR on SBS were significant (P<0.05). The frequency of adhesive failure in MBP and PBR groups was significantly higher than that in MBP+PBR and ZPP+PBR groups (P<0.05). The cohesive failure was significantly more frequent in ZPP+PBR group than in ZPP, MBP and PBR groups (P<0.05). Conclusion: Simultaneous application of zirconia primer and PBR is the most efficient technique for repair of all-ceramic zirconia restorations with composite resin.

Abutment fracture is a complication of dental implant treatment. When an abutment breaks, the remaining part should be retrieved without damaging the implant hex. In many cases, the implant‐abutment connection is cold‐welded, which makes it difficult to remove the remaining part. The aim of the present study was to describe a simple technique to retrieve the remaining part of a broken abutment.

Introduction: Phototherapy with a light-emitting diode (LED) is used in medicine due to its potential bio-stimulatory effects on the human body. However, controversy still exists regarding the efficacy of low-level laser therapy (LLLT) and phototherapy with LED. This in vivo study aimed to quantitatively and qualitatively assess the newly formed bone following LED phototherapy of the human maxillary sinuses. Methods: This randomized clinical trial (concurrent parallel) was conducted on 44 patients in two groups (n=22) at the Implant Department of Tehran University of Medical Sciences. Randomization was done by a random sequence generator program. The inclusion criteria were absence of chronic sinusitis and chronic bone marrow conditions, no history of surgery at the site, absence of diabetes mellitus, no history of chemotherapy or radiotherapy, maxillary premolar edentulism, and signing informed consent forms. Group A underwent LED phototherapy with 620 ± 2 nm wavelength for 20 minutes daily for a total of 21 days after sinus lift surgery. Group B served as the control group and did not receive phototherapy. After 6 months, the grafted sites were re-opened for implant placement, and bone biopsy samples were obtained using a trephine bur. The samples were stained with hematoxylin and eosin and inspected under a light microscope. The results were statistically analyzed using the Mann-Whitney U test. Both the surgeon and pathologist were blinded to the group allocation of patients. Results: Forty tissue specimens were analyzed. Insignificant differences existed between the two groups in terms of the degree of inflammation, bone quality, and maturity of collagen. Histological analyses revealed no significant difference in the mineralized areas of bone between the two groups (P>0.05). Conclusion: The results indicated that LED phototherapy cannot significantly enhance osteogenesis after sinus lift surgery. No side effects were observed in the experimental group.

Key Clinical MessageFull mouth rehabilitation by dental implants is complex in class III patients. Prediction of the outcome of orthognathic surgery in edentulous patients with no dental index or record is challenging. This report describes rehabilitation of an edentulous patient by placement of dental implants after prediction of the outcome of orthognathic correction.