Article: Fibre-reinforced composite crowns luted to implant abutments via electroformed primary copings: an in vitro retention study.[show abstract] [hide abstract]
ABSTRACT: The aim of this study was to investigate the retention values and mode of failure of metal crowns and fibre-reinforced composite crowns. Seventy-five implants and the corresponding abutments were used. After the galvanic copings were fabricated, the specimens were distributed into three groups: in group A traditional metal crowns were realized, whereas in groups B and C fibre-reinforced composite crowns were made. In group B the same resin based cement used in group A was employed for luting the fibre-reinforced composite crowns to the galvanic copings, while in group C a dedicated self-adhesive composite cement was used. All galvanic coping/crown assemblies were cemented onto abutments with Panavia 21 cement. Specimens were subjected to a pull-out test; median retentive values and standard deviations were calculated. All samples in the group A showed separation at the abutment-galvanic cap interface. All samples in the group B showed decementation at galvanic cap-crown interface. In 13 samples of the group C the decementation occurred at the abutment-galvanic cap interface and in 12 samples of this group the decementation occurred at the galvanic cap-crown interface. The mean retention value was 659.1 N±162.9 for group A, 304.7 N±101.4 for B and 635.4 N±155.9 for C. Differences between groups A/B and B/C are statistically significant (t-student test, P<0.01), while is not statistically different between groups A/C. When a self-adhesive composite cement is used, fibre-reinforced composite single crowns and conventional metal crowns show similar retentive performance.Minerva stomatologica 09/2012; 61(9):355-65.
Article: Fiber-reinforced composite inlay fixed partial dentures: the influence of restorative materials and abutment design on stress distribution investigated by finite element model.[show abstract] [hide abstract]
ABSTRACT: Fiber-reinforced composite may be successful used to fabricate inlay fixed partial dentures. This study used a finite element model to investigate three-dimensional stress distribution in a 3-unit fiber-reinforced composite fixed partial denture, and compared three types of fiber and three abutment configurations. A finite element model of a 3-unit fixed partial denture was used to investigate stress distribution in three different fiber-reinforced composite systems (1) Ribbond Triaxial plus Sinfony; 2) EverStick plus Sinfony; 3) Vectris Pontic/Frame plus Sinfony) and in three different abutment configurations (minimal distal-occlusal and mesial-occlusal preparation; extensive distal-occlusal and mesial-occlusal preparation; mesial-occlusal-distal preparation of both abutment teeth). Maximum load of 196 N was applied at the center of the occlusal and buccal surfaces of the pontic. Stress distribution was calculated in the tooth/restoration complex and in the abutment preparation. When a vertical load was applied, no substantial differences between stress amount in the molar and in the premolar connectors was found. When a lateral load was applied, the stress was greater in the premolar connector than in the molar connector. In all designs investigated, stress was concentrated at the cervical margins of the proximal boxes adjacent to the pontic; no stress concentrated at the occlusal box preparation surface. Within the limitations of this study, the results suggest that different fiber-reinforced composite systems show similar pattern of stress distribution. Stress concentrates at the connector areas and in the prepared teeth. Peak stress is at the cervical margin of the boxes adjacent to the pontic.Minerva stomatologica 10/2009; 58(10):459-70.
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ABSTRACT: The aim of this study was to evaluate the effect of sandblasting on the retentive strength of metal single crowns luted with a resin cement to Straumann implant/abutment assemblies. Fifty 4.1 mm-wide Straumann solid screw implants were mounted in self-polymerizing soft resin. Standard 5.5 mm-high, 8 degree tapered solid abutments were placed on each implant and torqued to 35 Ncm. Fifty metal castings were made using prefabricated burn-out caps. Each implant/abutment assembly and its corresponding metal casting was numbered and they were divided into two groups of 25. In the test group, the external surface of the abutments and the cavosurface of the corresponding metal casting were sandblasted. In the control group, neither the implant abutment nor the metal casting underwent sandblasting. Each metal casting was cemented onto its respective implant/abutment assembly using Panavia 21 (Kuraray Europe GmbH, Dusseldorf, Ger-many) resin cement. Specimens were then subjected to a pull-out test using a universal Instron testing machine. The load required to dislodge each crown was recorded and mean values were calculated for each group. Retention values were analyzed using the ANOVA test. The test group showed a higher mean retention value (83.78 kgf+/-19.61) than the control group (44.03 kgf+/-9.45) and the difference was statistically significant. Within the limitations of this in vitro study, the results suggest that sandblasting treatment significantly increases mechanical retention of crowns cemented using a resin cement. It is at the clinician's discretion to evaluate whether additional retention is desired in cementing an implant-supported fixed partial denture.Minerva stomatologica 04/2008; 57(3):95-101.
Article: Eating disorders: a threat for women's health. Oral manifestations in a comprehensive overview.[show abstract] [hide abstract]
ABSTRACT: The incidence of eating disorders has progressively increased over the last several years, mainly affecting both the health and quality of life of young women. Such disorders are primarily an outlet for manifest psychic suffering and secondarily, they jeopardize the integrity and function of multiple organ systems resulting in significant morbidity and sometimes, life-threatening outcomes. The complex emerging interplay of etiopathogenetic factors poses many challenges in their prevention and management, which is further complicated by a reluctance by patients with eating disorders to seek medical evaluation and treatment. Recognition of the oral manifestations is important because these signs and symptoms can provide insights about disease progression and parallel general health and psychic status. Oral health care providers may be one of the few providers contacted by this patient population seeking recall prophylaxis or urgent dental care. Thus, improving understanding and knowledge of both general medical aspects of eating disorders and their oral manifestations could be of great impact in elevating the attention of health providers towards this group of very debilitating disorders and, consequently, improving their overall prognosis. In this paper we will review and discuss all these aspects.Minerva stomatologica 06/2007; 56(5):281-92.
M Fuzzi, G Rappelli[show abstract] [hide abstract]
ABSTRACT: This study evaluates the clinical behavior of ceramic inlays placed during the past decade. One hundred eighty-two inlays were examined in 66 patients. The interval between placement and assessment was on average 5.9 years +/- 2.7, ranging from 2 to 11.7 years. Restorations still present at the time of evaluation were clinically assessed according to modified USPHS criteria. Kaplan-Meier statistical analysis was used to assess the survival rate. According to USPHS criteria, good results were obtained for color match, marginal discoloration, recurrent caries, contour, and marginal integrity. Six inlays failed: four for endodontic reasons, one due to recurrent caries, and the other due to fracture. The results indicate that a success rate of 95% could be predicted at 11.5 years. The lack of recurrent caries, the only slight changes in marginal discoloration and color match, combined with the excellent longevity prove that ceramic inlays are a valuable tool for the restoration of posterior teeth.The journal of adhesive dentistry 02/1999; 1(1):71-9. · 1.11 Impact Factor