El arco facial en la elaboración de las férulas oclusales tipo Míchigan / Face bows in the production of Michigan occlusal splints

Introducción: la férula oclusal tipo Míchigan (FOM) es un dispositivo usado frecuentemente para el manejo de pacientes con bruxismo. La literatura menciona el uso del arco facial para el montaje de modelos en el articulador semiajustable, sin embargo el beneficio de este en la elaboración de las FOM aún es controvertido. Por lo tanto el objetivo de esta investigación fue comparar el registro de número de puntos de contacto y el tiempo de ajuste entre las FOM elaboradas con y sin el uso del arco facial en pacientes con diagnóstico de bruxismo. Métodos: se elaboraron 90 férulas entregadas a 45 pacientes de la Clínica de Rehabilitación Benemérita Universidad Autónoma de Puebla (BUAP), previo diagnóstico de bruxismo. Las dos férulas elaboradas (una con modelos montados con arco facial y otra sin él), se compararon en el articulador y clínicamente. Se registró el número de puntos de contacto obtenidos en ambas férulas y el tiempo de ajuste requerido. Las comparaciones se hicieron con la prueba estadística de Wilcoxon y significancia menor a 0,05. Resultados: la media de puntos de contacto en boca de las férulas con el uso del arco fue superior (11,67) a la de sin uso del arco (11,58) sin diferencias significativas (p = 0,799). El tiempo de ajuste fue superior en las férulas elaboradas sin arco (51 s) que con arco (33 s), sin diferencias significativas (p = 0,332). Conclusión: no existen diferencias significativas con el uso del arco facial o sin él para la elaboración de las FOM en pacientes bruxómanos.

Introduction: Michigan occlusal splints (MOS) are frequently used for the management of patients with bruxism. The literature mentions the use of face bows for mounting models in semi-adjustable articulators, but its benefit in the production of MOS is still controversial. Therefore, the objective of this study was to compare the record of number of contact points and mounting time between MOS made with and without face bows in patients diagnosed with bruxism. Methods: a total of 90 splints were made and distributed among 45 patients diagnosed with bruxism at the Oral Rehabilitation Clinic of Benemérita Universidad Autónoma de Puebla (BUAP). The two splints (one made with a face bow mounted model and the other one without it) were compared at the articulator and clinically. The number of obtained contact points was recorded in both splints as well as the time needed for mounting. The comparisons were made with Wilcoxon statistical test and a significance level lower than 0.05. Results: the splints with face bows showed a greater average of contact points in the mouth (11.67) compared with the ones without face bows (11.58), with no significant difference (p = 0.799). Mounting time was higher in the splints made without face bows (51 s) compared with the ones with face bows (33 s), with no significant difference (p = 0.332). Conclusion: there are no significant differences in using face bows for developing MOS in bruxism patients.

Two-year clinical performance of Clearfil SE and Clearfil S3 in restoration of unabraded non-carious class V lesions.

This study was undertaken to evaluate the two-year clinical performance of a self-etching primer and a self-etching adhesive, both of which employ the same acidic monomer. Forty pairs of restorations of AP-X hybrid resin composite (Kuraray Co, Ltd, Osaka, Japan) were placed in caries-free cervical erosion/abfraction lesions. Based on insensitivity to air, the dentin in 62% of these lesions was considered to be sclerotic. The restorations were placed with no abrasion of tooth surfaces, except for cleaning with plain pumice and no use of phosphoric acid etching, which is counter to the manufacturer's instructions that call for etching of unprepared enamel. One restoration from each pair was placed using Clearfil SE Bond, an adhesive employing a self-etching primer, and the other was placed using Clearfil S3 Bond, a self-etching adhesive. To emulate the results likely to occur in a private practice, the restorations were placed by well-educated, experienced clinicians who had no particular expertise in adhesive dentistry research and who placed the restorations according only to their interpretation of the manufacturer's instructions. The restorations were clinically evaluated at baseline and at 6, 12 and 24 months, using modified Ryge/USPHS criteria. For both products, retention of 81%-84% of the restorations was observed over two years, which is lower than has been previously observed with these products and is likely due to limitations in the manufacturer's instructions compounded by inexperience of the operators in adhesive dentistry research. One restoration placed with each adhesive demonstrated secondary caries, which was probably attributable to the study being conducted in a non-fluoridated area and which reduced the percentages of clinically successful restorations to 78%-81%. No statistically significant difference (p = 0.50) between the two adhesives was observed in overall performance.

The effect of chlorhexidine on dentin hybrid layers in vivo.

This in vivo study evaluated by TEM the degradation of dentin hybrid layers in deep occlusal resin composite restorations. Caries-free premolars scheduled for extraction as part of orthodontic treatment were prepared, restored and evaluated after two and six months. The adhesive used was a single-bottle etch-and-rinse product (Single Bond Plus, 3M ESPE). Control group restorations were placed according to the manufacturer's instructions, while the experimental group received application of a 2% solution of chlorhexidine digluconate after etching. No degradation was observed in either group after two months. Slight degradation was found in the control group after six months, but none was observed in the experimental group. In vitro testing showed no significant difference in microtensile bond strength between the control and experimental adhesive protocols.

Eighteen-month clinical performance of a self-etching primer in unprepared class V resin restorations.

This study evaluated the clinical performance of unprepared Class V resin composites, placed using a self-etching primer and a single-bottle adhesive, over a period of 18 months. Thirty-eight pairs of restorations of Renew hybrid resin composite (BISCO, Inc) were placed using adhesives from the same manufacturer in caries-free cervical erosion/abfraction lesions. Based on insensitivity to air, the dentin in 76% of these lesions was considered to be sclerotic. The restorations were placed without abrasion of tooth surfaces, except for cleaning with plain pumice. One of each pair was placed using Tyrian, a self-etching primer and the other was placed using One-Step, a single-bottle adhesive placed after acid etching. Both the etchant and self-etching primer were applied for 20 seconds. The restorations were clinically evaluated at baseline, 6, 12 and 18 months, using modified Ryge/USPHS criteria. For both adhesives, very low retention of 50% to 56% of the restorations was observed over 18 months, leading to the conclusion that tooth surfaces must receive some additional treatment prior to restoration with these adhesives. No statistically significant difference (p=0.75) between the two adhesives was observed in overall performance, and dentinal sclerosis and axial depth did not appear to be important factors in the study.

Two-year clinical performance of Class V resin-modified glass-lonomer and resin composite restorations.

While a one-year report had been previously published, this study was undertaken to evaluate the clinical performance and appearance of a resin-modified glass ionomer and a resin composite over two years. Thirty-seven pairs of restorations of FujI II LC and Z 250/Single Bond were placed in caries-free cervical erosion/abfraction lesions without tooth preparation. Restorations were clinically evaluated at baseline, 6, 12, 18 and 24 months using modified Ryge/USPHS criteria. No statistically significant difference (p = 0.13) was observed in the overall performance of the materials. Retention was 96% for the resin-modified glass ionomer and 81% for the resin composite, with no additional restorations of either material lost after one year. As previously reported, retention of the Z 250 restorations at six months was below the minimum specified in the ADA Acceptance Program for Dentin and Enamel Adhesives. The resin composite restorations generally had a better appearance, with a 100% alpha rating in color match, versus 85% for the resin-modified glass ionomer.