The influence of implant location and position characteristics on peri-implant pathology..

Peri-implant pathology is a multifactorial disease, incorporating biological and biomechanical components in its pathogenesis; however; few studies address the possible risk factors. This study investigated the effect of implant location and position characteristics on the occurrence of Peri-implant pathology. A total of 1350 patients with dental implants were included 270 patients with peri-implant pathology and 1080 healthy controls. Results demonstrated that in the absence of bacterial plaque and smoking, the variable proximity of the implant to other implants or teeth revealed a significant difference between groups with a protective effect, but not in the presence of bacterial plaque and smoking.

e-Modulus of resin cements as a function of curing source and storage time.

AIM: The aim of this study was to evaluate the e-modulus of two resin cements, with different curing sources and storage times, by flexural strength. METHODS: Ninety-six rectangular specimens were prepared from 2 dual-cured resin cements (Bistite II DC and Panavia F 2.0). A QTH light-curing unit (XL 3000) and a light-emitting diode (Optilight CL) were used for curing. The specimens were stored for 24 hours or 30 days. Testing consisted of three-point flexural strength, with 50 kg of load and crosshead speed of 0.5 mm/min. Data were analyzed with analysis of variance and Tukey test (5%). RESULTS: When QTH light curing was used, Panavia had flexural strengths of 183.30 MPa at 24h and 112.30 at 30 days; whereas, Bistite had strengths of 160.20 MPA at 24h and 120.20 MPa at 30 days. However, when LED was used, the values were significantly lower for both cements. The main effects of cement type, storage time and curing unit type were statistically significant, as were the statistical interactions of cement/curing unit and time/curing unit. CONCLUSION: The experimental effects of cement type, storage time and curing unit type profoundly affected e-modulus.

Effect of the surface treatment of plain carbon fiber posts on the retention of the composite core: an in vitro evaluation.

This study aims to evaluate the role of surface treatments performed on plain carbon fiber posts, in relation to serrated carbon fiber posts, in the retention of the composite core. Fifty carbon fiber posts received surface treatments in order to verify their influence on the retention of the core material. An acrylic resin mold was developed in order to precisely fit the post, leaving a machined space to accommodate a self-curing composite resin. After the surface treatment, a primer was applied on the coronal portion of all posts, which were then dried. They were fitted to the mold and received a 3 mm composite core. All specimens were thermocycled and then stored in distilled water for a week. Tension test was performed at a speed of 0.5 mm/min until there was lack of adhesion or fracture of the core. The conclusions were: a) the values of retention related to aluminum oxide spray (group A), depth cutter diamond burs (group C) and posts with machined coronal portion (group D) were comparable to those of serrated posts (group E), although no statistically significant difference between these groups was found; b) the mean values of core retention in group B (medium grit diamond burs) were statistically lower than those of other groups.

Microleakage evaluation of pit and fissure sealants done with different procedures, materials, and laser after invasive technique.

This study evaluated the microleakage of pit and fissure sealants after different surface preparation (invasive technique and laser irradiation) and the use of different materials (fluoride resin-filled sealant, resin-modified glass ionomer cement and adhesive system). Eighty-four pre molars were used in this study, which were divided into seven groups. After the accomplishment of the different treatments, these were submitted to thermocycling process and assess for microleakage by examination under an epifluorescent microscope and scored zero to seven. Two specimens of each group were observed under scanning electron microscope (SEM). The results showed that laser irradiation did not lessen microleakage in pit and fissures when using a filled-resin sealant with fluoride or a resin-modified glass ionomer cement. The use of laser irradiation and adhesive system, followed by a resin-filled sealant with fluoride, showed the lowest microleakage scores in pit and fissures. Comparing this group to the resin-modified glass ionomer cement group, there was statistical significance. The use of a adhesive system decreased microleakage when using a fluoride resin-filled sealant with or without previous laser irradiation; although it was not statistically significant.

Dentin bond strength: influence of laser irradiation, acid etching, and hypermineralization.

OBJECTIVE: The purpose of the present study was to investigate the effects of ND:YLF laser irradiation (1.31 J/cm2; 250 mJ per pulse), acid etching, and hypermineralization on the shear bond strength (SBS) of the Scotchbond Multi-Purpose Plus (3M Dental Products) bonding system. SUMMARY BACKGROUND DATA: Previous studies had shown that the pretreatment of the dentin substrate with laser irradiation can influence the SBS. METHODS: Sixty bovine incisors were selected and stored at -18 degrees C. Dentinal buccal surface was exposed and radiographs were taken to control dentin thickness. The specimens were separated into 2 groups: (1) the control, which was kept in distilled water at 4 degrees C; (2) the hypermineralized, which was kept in hypermineralizing solution at 4 degrees C for 14 days. Each group was divided into 3 subgroups according to the type of dentin pretreatment used: M (acid etching + primer + bond); AL (acid etching + primer + bond + laser); and LA (laser + acid etching + primer + bond). A standard composite resin cylinder (Z100-3M) was bonded to the dentinal surface and the SBS performed on an Instron machine (500 Kg load cell at 0.5 mm/min), followed by scanning electron microscopy (SEM) and x-ray diffraction analysis. RESULTS: Analysis of variance (ANOVA) determined that the pretreatments influenced the SBS values (p < 0.05): AL (9.96 MPa), M (7.28 MPa), and LA (4.87 MPa). The interaction between the group and pretreatment factors also influenced the SBS (p < 0.05). The highest values were obtained for the interaction control/AL (11.64 MPa). CONCLUSION: The results suggested that dentin treatment with laser after the application of the adhesive system is efficient in achieving higher bond strength and is promising as a possible new adhesive substrate.

A retrospective look at esthetic resin composite and glass-ionomer Class III restorations: a 2-year clinical evaluation.

OBJECTIVE: A restorative material for Class III cavities must, besides being functional, be esthetically satisfactory, providing good working conditions and several shade and color options. A clinical evaluation was initiated to compare the suitability of resin composite and glass-ionomer cement materials for such restorations. METHOD AND MATERIALS: Forty-two Class III conservative cavities, esthetically important because of facial extensions, were selected. Resin composite restorations were placed in 21 cavities, and the remaining 21 were restored with glass-ionomer cement. The following characteristics were studied: color or esthetics, anatomic shape, surface texture, staining, marginal infiltration, dental plaque retention, and occurrence of fracture. After 24 months, the restorations were evaluated. RESULTS: The only statistically significant difference between the resin composite and glass-ionomer cement restorations in the experimental period involved color or esthetics. CONCLUSION: Resin composites and glass-ionomer materials provide excellent functional and esthetic results in Class III cavities when properly indicated.

A 2-year clinical evaluation of fluoride-containing pit and fissure sealants placed with an invasive technique.

The aim of this study was to clinically evaluate fluoride-containing sealants in teeth subjected to minimal enamel reduction (preventive resin restorations). Two hundred fourteen sealants (109 FluroShield and 105 Delton Fluor) were applied in 153 teeth of 32 subjects. The sealants were evaluated for superficial irregularities, marginal adaptation, retention, and caries after 6, 12, 18, and 24 months. After 6, 12, and 18 months, the attendance at recall was 100.00%. After 24 months, 93.75% of subjects returned for reevaluation. Although total or partial loss of sealant occurred in a few instances, no occlusal caries was found in any tooth at any recall. No statistically significant differences in the results of the clinical evaluation were found between sealant in the maxillary and mandibular dentitions.