External validation of a clinical prediction tool for the use of manual therapy for patients with temporomandibular disorders: a protocol for a prospective observational study.

INTRODUCTION: Clinical guidelines recommend conservative treatment for the management of temporomandibular disorders (TMD), and manual therapy directed to temporomandibular structures is commonly applied to reduce pain and improve function. In a recent prospective study, we developed a clinical prediction tool based on an array of predictors to identify people with TMD who are likely to experience significant pain relief and functional improvements following a programme of manual therapies (MTP) applied to temporomandibular structures. The purpose of this study is to externally validate in a different sample (temporal validation) the prediction model obtained in the initial study. METHODS/ANALYSIS: This observational prospective study will recruit a cohort of 120 adults with TMD from a Dental Hospital in Italy. The intervention will be an MTP consisting of four sessions (once per week) of manual therapy applied to temporomandibular structures. Candidate predictors included in the predictive model will be pain intensity during mouth opening, treatment expectations, number of pain locations, central sensitisation, TMD pain duration and maximal mouth opening. Outcome measures (i.e., pain intensity, functional improvement) will be collected before starting the MTP, after the last session and after 1 month (2 months from baseline). A reduction of pain intensity by at least 30% will be considered a good outcome. External validity of the prediction model will be evaluated after the last session by measuring its calibration, discrimination and overall fit. Additionally, the performance of the model will be evaluated considering the clinical outcomes collected 1 month after the last MTP session. ETHICS AND DISSEMINATION: Ethical approval was obtained from the Ethics Committee of the Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Italy. The results will be submitted for publication in a peer-reviewed journal, and the prediction model will be implemented in a web-based calculator to facilitate its use by clinicians. TRIAL REGISTRATION NUMBER: NCT03990662.

Effect of Long-Term Brushing on Deflection, Maximum Load, and Wear of Stainless Steel Wires and Conventional and Spot Bonded Fiber-Reinforced Composites.

Fiber-reinforced composite (FRC) retainers are an aesthetic alternative to conventional Stainless Steel splints. They are generally used with a full bonded technique, but some studies demonstrated that they could be managed with a spot bonding technique to significantly decrease their rigidity. In order to propose this FRC spot bonding technique for clinical use, the aim of this study was to evaluate mechanical properties and surface wear of fibers left uncovered. Tests were made by simulating tooth brushing, comparing FRC spot bonding technique splints with stainless steel and FRC traditional technique splints. Specimens were tested both at 0.1 mm of deflection and at maximum load, showing higher values of rigidity for the FRC full bonded technique. After tooth brushing, no significant reduction in values at 0.1 mm deflection was reported, while we found a similar reduction in these values for the Stainless Steel and FRC spot bonding technique at maximum load, and no significant variation for the FRC full bonded technique. SEM images after tooth brushing showed wear for FRC fibers left uncovered, while no relevant wear signs in metal and conventional FRC fibers were noticed. Results showed that FRC spot bonding technique has advantages in mechanical properties when compared to the FRC traditional full bonding technique, also after tooth brushing. However, the surface wear after tooth brushing in the FRC spot bonding technique is considerable and other tests must be performed before promoting this technique for routine clinical use.

Bending Properties of Fiber-Reinforced Composites Retainers Bonded with Spot-Composite Coverage.

Orthodontic and periodontal splints are prepared with round or flat metallic wires. As these devices cannot be used in patients with allergy to metals or with aesthetic demands, fiber-reinforced composite (FRC) retainers have been introduced. Stiffness of FRC materials could reduce physiologic tooth movement. In order to lower rigidity of conventional FRC retainers, a modified construction technique that provided a partial (spot) composite coverage of the fiber has been tested and compared with metallic splints and full-bonded FRCs. Flat (Bond-a-Braid, Reliance Orthodontic Products) and round (Penta-one 0155, Masel Orthodontics) stainless steel splints, conventional FRC splints, and experimental spot-bonded FRC retainers (Everstick Ortho, StickTech) were investigated. The strength to bend the retainers at 0.1 mm deflection and at maximum load was measured with a modified Frasaco model. No significant differences were reported among load values of stainless steel wires and experimental spot-bonded FRC retainers at 0.1 mm deflection. Higher strength values were recoded for conventional full-bonded FRCs. At maximum load no significant differences were reported between metallic splints (flat and round) and experimental spot-bonded FRCs, and no significant differences were reported between spot- and full-bonded FRC splints. These results encourage further tests in order to evaluate clinical applications of experimental spot-bonded FRC retainers.

Spot-Bonding and Full-Bonding Techniques for Fiber Reinforced Composite (FRC) and Metallic Retainers.

Fiber reinforced Composite (FRC) retainers have been introduced as an aesthetic alternative to conventional metallic splints, but present high rigidity. The purpose of the present investigation was to evaluate bending and fracture loads of FRC splints bonded with conventional full-coverage of the FRC with a composite compared with an experimental bonding technique with a partial (spot-) resin composite cover. Stainless steel rectangular flat, stainless steel round, and FRC retainers were tested at 0.2 and 0.3 mm deflections and at a maximum load. Both at 0.2 and 0.3 mm deflections, the lowest load required to bend the retainer was recorded for spot-bonded stainless steel flat and round wires and for spot-bonded FRCs, and no significant differences were identified among them. Higher force levels were reported for full-bonded metallic flat and round splints and the highest loads were recorded for full-bonded FRCs. At the maximum load, no significant differences were reported among spot- and full-bonded metallic splints and spot-bonded FRCs. The highest loads were reported for full bonded FRCs. The significant decrease in the rigidity of spot-bonded FRC splints if compared with full-bonded retainers suggests further tests in order to propose this technique for clinical use, as they allow physiologic tooth movement, thus presumably reducing the risk of ankylosis.