Joseph Ghoubril

Impacted or transposed teeth present a common yet challenging issue in dentistry. These conditions occur when teeth fail to erupt properly or emerge in abnormal positions within the dental arch. This article explores the evolving landscape of therapeutic strategies for impacted or transposed teeth, emphasizing a multidisciplinary and patient-centered approach. By adopting a multidisciplinary approach involving orthodontists, oral surgeons, and other dental specialists, clinicians can tailor treatment plans to address individual needs and optimize outcomes. Therapeutic reassessment of impacted or transposed teeth represents a paradigm shift in modern dentistry, emphasizing personalized care, minimally invasive techniques, and interdisciplinary collaboration.

The association of the V-prep and a resin-modified glass ionomer cement (RMGIC) has shown to be a suitable alternative for the orthodontic bracket bonding procedure in vitro. The aim of this study was to evaluate over eighteen months the clinical bonding failure and survival rates of the conventional bonding technique using the Transbond XT (3M Unitek, Monrovia, CA, USA) and the RMGIC Fuji Ortho LC (GC Corporation, Tokyo, Japan) prepared with the V-prep. Therefore, one operator using the straight-wire technique bonded two hundred metallic brackets to upper and lower premolars of twenty-five patients requiring an orthodontic treatment. The randomized trial was a single-blind design in a split-mouth comparison. Each patient was randomly allocated one of the two bonding systems for each premolar on each side of the mouth. The bonding and rebonding techniques were standardized throughout the trial and bond failure was recorded each month for a period of eighteen months. The survival rates of the brackets were estimated by Kaplan–Meier and log-rank test (p < 0.05). A total of 200 orthodontic brackets were included in the study with a significant lower failure rate of 9.0% for the V-prep and RMGIC compared to 25.0% for the conventional bonding technique (p < 0.05). A higher survival rate was observed for the V-prep and RMGIC (16.36 months) over the conventional bonding technique (13.95 months) (p < 0.05). Lower premolar bonding failure was higher than upper premolar for both bonding techniques. The V-prep followed by RMGIC, with enamel surface protection abilities, can be used as an alternative bonding technique in an orthodontic treatment.

Objective: To compare the three-dimensional (3D) effects of canine traction on the maxillary teeth when using two different traction methods, the continuous and the segmented arch wire techniques; then to test whether adding a transpalatal arch (TPA) would affect their response to traction. Design: Finite element analysis. Methods: A cone-beam computed tomography (CBCT) scan of a patient with bilateral palatally impacted canines was chosen, from which a 3D model was derived and imported into ABAQUS. Two arch wires were modelled, a continuous round one and a segmented rectangular one. Four models were obtained by adding a TPA to both techniques. A 100° imposed rotation was then applied at the intersection between the vertical loop and the horizontal segment of each wire. Initial displacement of the maxillary tooth in the labio-lingual and in the vertical directions was measured. The absolute maximum principal stress of the periodontal ligament (PDL) was also assessed. Results: Traction using a continuous arch wire led to different movement patterns of all teeth, some of them were tipped in a labial direction while others were lingually tipped. Traction using a segmented arch wire resulted in a retroclination of the posterior teeth and a proclination of the anterior teeth with a high level of stress on the premolars’ PDL. Adding the TPA only affected the displacement of the first molars. The right side showed a maximum displacement of the first premolar, while the left side showed it on the lateral. The total displacement on the right side was higher than the left side. Conclusion: The segmented technique caused a uniform displacement of all teeth while the continuous one showed a non-uniform displacement. The angulation and position of the vertical loop affected the displacement of the maxillary teeth. The addition of a TPA acted only on the first molars.

Background: In orthodontic treatment, mini-screws can provide maximum anchorage conditions. If the miniscrew stability is compromised, this could jeopardize the outcomes of the orthodontic treatment or biomechanics. Photobiomodulation therapy (PBMt) is beneficial for biological tissues since it promotes wound healing with its anti-inflammatory and osteo-stimulatory properties. Objectives: The purpose of this study was to evaluate the effects of 810-nm Diode PBMt on the stability of orthodontic mini-screws for three months. Trial Design: Parallel, allocation ratio 1:1. Methods: Using a split-mouth technique, a total of 40 mini-screws were randomly allocated (1:1) to either a placebo laser application (P group) or a laser PBMt (L group). An 810-nm diode laser irradiation of 1 W output power, operating in continuous wave mode for 50 s, was applied in a sweeping movement at a 22 mm distance from the mini-screws. The allocated mini-screws first received PBMt at baseline, then every other day for five days, and then at each orthodontic visit (every three weeks) for a period of three months. At each visit, the stability of the mini-screws was measured by the Osstell Implant Stability Quotient (Osstell ISQ) at three points: lower, upper, and distal to the mini-screw. Results: The lower, upper, and distal ISQ values of irradiated and non-irradiated mini-screws significantly decreased at each point over time (p < 0.001). No significant difference was found in the global ISQ values between the laser and the placebo group (p > 0.05). Conclusion: PBM did not significantly increase the stability of orthodontic mini-screws over a period of three months. Trial Registration: Protocol was approved by the Research Ethics Committee of the Faculty of Dental Medicine of Saint Joseph University, Beirut, Lebanon University (#USJ/2019/161).

Background: The aim of this study was to find the best surface treatment for CAD/CAM provisional crowns allowing the optimal bond strength of metal brackets. Methods: The sample consists of 30 lower bicuspids and 180 provisional crowns. The provisional crowns were randomly divided into six different groups. Orthophosphoric acid etching (37%) was applied to 30 lower bicuspids. The provisional crowns had undergone different surface treatments. Group 1: No treatment (Control Group). Group 2: Diamond bur. Group 3: Sandblasting. Group 4: Plastic Conditioner. Group 5: Diamond bur and Plastic Conditioner. Group 6: Sandblasting and Plastic Conditioner. The brackets in all groups were identically placed using Transbond XT^® Primer and Transbond XT^® Paste. Then, the entire sample underwent an artificial aging procedure, and a measurement of the bond strength was conducted. After debonding, the surface of the crowns was examined to determine the quantity of the adhesive remnant. Results: Bonding to natural crowns recorded the highest average, followed by the averages of groups 5 and 6. However, group 1 recorded the lowest average. Groups 2 and 4 had very close averages, as well as groups 5 and 6. A statistically significant difference between the averages of all groups was recorded (p < 0.001) except for groups 2 and 4 (p = 0.965) on the one hand, and groups 5 and 6 (p = 0.941) on the other hand. Discussion: The bonding of brackets on provisional crowns is considered a delicate clinical procedure. In fact, unlike natural crowns, the orthophosphoric acid usually used does not have any effect on the surface of provisional crowns. Conclusions: Using a diamond bur combined with the plastic conditioner and sandblasting combined with that same product resulted in a bond strength close to natural crown.