Ricardo Alves de Souza

Periodontal and microbiologic evaluation of 2 methods of archwire ligation: ligature wires and elastomeric rings.

INTRODUCTION Prophylactic programs to prevent dental biofilm accumulation must be implemented to minimize the risk for periodontal diseases in orthodontic patients. Therefore, we assessed the possible periodontal and microbiologic changes resulting from the use of 2 methods of orthodontic archwire ligation: elastomeric rings and steel ligatures. METHODS The following parameters were measured: plaque index, gingival bleeding index, probing depth, and biofilm samples from the maxillary second premolars and the mandibular lateral incisors were evaluated in 14 subjects without clinical signs of gingival inflammation before orthodontic appliance placement and after 6 months of treatment. Each orthodontic arch was fixed with elastomeric rings on 1 side of the midline, and steel ligatures were used on the opposite side. Polymerase chain reaction analysis was used to detect Porphyromonas gingivalis, Tannerella forsythia, Actinobacillus actinomycetemcomitans, Prevotella intermedia, and P nigrescens. RESULTS The elastomeric rings were associated with a higher score for plaque index and bleeding than steel ligatures, as well as many positive sites of T forsythia and P nigrescens (P <0.05). CONCLUSIONS Elastomeric rings favored these 2 periodontopathogens and harmed gingival conditions.

Perception of the esthetic impact of mandibular incisor extraction treatment on laypersons, dental professionals, and dental students.

OBJECTIVE To evaluate the degree of perception of laypersons, dental professionals, and dental students regarding dental esthetics in cases with mandibular central incisor extraction. MATERIALS AND METHODS Using a smile photograph of a person with normal occlusion and all teeth, modifications were made to reflect the extraction of a mandibular incisor of various compositions and sizes. For this purpose a program specifically for image manipulation (Adobe Photoshop CS3, Adobe Systems Inc) was used. After manipulation the images were printed on photographic paper, attached to a questionnaire and distributed to laypersons, dental professionals, and dental students (n  =  90) to evaluate the degree of perception and esthetic using a scale of attractiveness, where 0  =  hardly attractive, 5  =  attractive, and 10  =  very attractive. The differences between examiners were checked by the Mann-Whitney test. All the statistics were performed with a confidence level of 95%. RESULTS The results demonstrated the skill of the dental professionals and dental students in perceiving the difference between cases of normal occlusion and cases where an incisor was lacking (P < .05). The photograph in which the lateral incisors were shown to be larger than the central incisor was the one that obtained the highest value among the cases of extraction in all groups of evaluators. CONCLUSIONS It can be concluded that dental professionals and dental students are more skillful at identifying deviation from normality. In addition, central incisor extraction should always be discarded when there are other treatment options available.

Effect of 10% papain gel on enamel deproteinization before bonding procedure.

OBJECTIVE To test the null hypothesis that enamel deproteinization with 10% papain gel does not increase the shear bond strength of orthodontic brackets bonded with resin-modified glass ionomer cement (RMGIC). MATERIALS AND METHODS One hundred and twenty bovine incisors were used and divided into eight groups: 1) Transbond XT according to the manufacturers recommendations, 2) Transbond XT deproteinized with 10% papain gel, 3) RMGIC without enamel deproteinization and without etching, 4) RMGIC without enamel etching and with deproteinization with 10% papain gel, 5) RMGIC deproteinized with 10% papain gel and etched with polyacrylic acid, 6) RMGIC deproteinized with 10% papain gel and etched with phosphoric acid, 7) RMGIC deproteinized with 2.5% sodium hypochlorite, and 8) RMGIC etched with polyacrylic acid. After bonding, the mechanical tests were performed in a Universal mechanical test machine. The values obtained were submitted to an analysis of variance and afterward to the Tukey test (P < .05). RESULTS It was demonstrated that group 2 presented the highest shear bond strength value, and this differed statistically from the others; group 3 presented the lowest value and showed no differences from groups 4, 5, 7, and 8. Regarding the Adhesive Remnant Index, groups 2 and 6 presented the best results and groups 3 and 8 the worst. It could be concluded that enamel deproteinization with 10% papain gel increases the shear bond strength, irrespective of the etching agent. CONCLUSIONS The hypothesis is rejected. Papain gel was shown to be a new ally in the orthodontic clinic.