FMD - Artigos em Revistas Internacionais
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- An association between temporomandibular disorder and gum chewingPublication . Correia, Diana; Dias, Maria Carlos Real; Moacho, Antonio; Crispim, Pedro; Luís, Henrique; Oliveira, Miguel; Caramês, JoãoThis single center, randomized, small study sought to investigate the prevalence and frequency of chewing gum consumption, and whether there is a relationship between these factors and the presence of symptoms associated with temporomandibular disorder (TMD). Subjects were divided into 7 groups based on their parafunctional oral habits. Of these, subjects who chewed gum were divided into 5 subgroups (A-E) based on their gum chewing habits. Group A chewed gum <1 hour/day (n = 12), Group B chewed gum 1-2 hours/day (n = 11), Group C chewed gum 3 hours/day (n = 6), and Group D chewed gum >3 hours at a time (n = 8); the frequency of gum chewing in Groups A-D was once a week. Group E subjects chewed gum 1-3 times/week for at least 1 hour each occurrence (n = 2). Sixty-three percent of the subjects in Group D reported TMD symptoms of arthralgia and myofascial pain. Thirty-three percent of the subjects in Group C showed symptoms of arthralgia. Eighty-three percent of the subjects in Group A and 27% in Group B reported myofascial pain. All subjects in Group E reported masseter hypertrophy. The remaining 2 groups were Group F, subjects that didn't chew gum but had other parafunctional oral habits (n = 2), and Group G, subjects who didn't have parafunctional oral habits (n = 12).
- Biodegradation of acrylic based resins: a reviewPublication . Bettencourt, Ana F.; Neves, Cristina B.; Almeida, Marise S. de; Pinheiro, Lídia M.; Oliveira, Sofia Arantes e; Lopes, Luís P.; Castro, Matilde F.Objectives. The development of different types of materials with application in dentistry is an area of intense growth and research, due to its importance in oral health. Among the different materials there are the acrylic based resins that have been extensively used either in restorations or in dentures. The objective of this manuscript was to review the acrylic based resins biodegradation phenomena. Specific attention was given to the causes and consequences of materials degradation under the oral environment. Data and sources. Information from scientific full papers, reviews or abstracts published from 1963 to datewere included in the review. Published materialwas searched in dental literature using general and specialist databases, like the PubMED database. Study selection. Published studies regarding the description of biodegradation mechanisms, in vitro and in vivo release experiments and cell based studies conducted on acrylic based resins or their components were evaluated. Studies related to the effect of biodegradation on the physical and mechanical properties of the materials were also analyzed. Conclusions. Different factors such as saliva characteristics, chewing or thermal and chemical dietary changes may be responsible for the biodegradation of acrylic based resins. Release of potential toxic compounds from the material and change on their physical and mechanical properties are the major consequences of biodegradation. Increasing concern arises from potential toxic effects of biodegradation products under clinical application thus justifying an intensive research in this área.
- Biomarkers of kidney integrity in children and adolescents with dental amalgam mercury exposure: findings from the casa pia children’s amalgam trial.Publication . Woods, James S.; Martin, Michael D.; Leroux, Brian G.; DeRouen, Timothy A.; Bernardo, Mario F.; Luis, Henrique S.; Leitão, Jorge G.; Kushleika, John V.; Rue, Tessa C.; Korpak, Anna M.Mercury is toxic to the kidney, and dental amalgam is a source of mercury exposure. Few studies have evaluated the effects of dental amalgam on kidney function in a longitudinal context in children. Here, we evaluated urinary concentrations of glutathione S-transferases (GSTs) α and π as biomarkers of renal proximal and distal tubular integrity, respectively, and albumin as a biomarker of glomerular integrity in children and adolescents 8-18 years of age over a 7 year course of dental amalgam treatment. Five hundred seven children, 8-12 years of age at baseline, participated in a clinical trial to evaluate the neurobehavioral and renal effects of dental amalgam in children. Subjects were randomized to either dental amalgam or resin composite treatments. Urinary GSTs α and π, albumin and creatinine concentrations were measured at baseline and annually on all subjects. Results were evaluated using linear regression analysis. GST-α concentrations were similar between treatment groups and in each sex and race (white vs nonwhite) group in each follow-up year. GST-π levels tended upward over the course of follow-up by 4- to 6-fold. This increase was seen in all groups irrespective of treatment, race or gender. Females had GST-π levels approximately twice those of males at all ages. Albumin concentrations were constant throughout the follow-up period and did not differ by treatment, although females had 39% higher albumin levels than males. Additionally, we found no significant effects of amalgam treatment on the proportion of children with microalbuminuria (>30 mg/g creatinine). These findings are relevant within the context of children’s health risk assessment as relates to the safety of mercury exposure from dental amalgam on kidney function. These data also provide normative values for sensitive indices of renal functional integrity that may serve in the evaluation of children and adolescents with renal disorders.
- Ceramic repair: influence of chemical and mechanical surface conditioning on adhesion to zirconiaPublication . Barragan, Gonçalo; Chasqueira, Filipa; Oliveira, Sofia ArantesAims: To evaluate the influence of mechanical surface treatment and chemical primer application on the composite shear bond strength to zirconia. Methods: Eighty blocks of Lava Frame Zirconia were randomly assigned to the experimental groups, according to the several possible combinations between mechanical (untreated/aluminum oxide sandblast) and chemical treatment (no primer/Monobond Plus/Experimental Zirkon-Primer/Z-Prime Plus) (n=10). Adhesive system and composite resin were then applied, and samples were thermal cycled (5ºC-55ºC, 500 cycles). Shear bond strength tests and failure mode analysis were performed. SBS data were analyzed by two-way ANOVA, followed by Student-Newman-Keuls post-hoc tests, and failure mode by Kruskal-Wallis and Mann-Whitney tests (p<0.05). Results: Shear bond strength mean values ranged from 6.9 to 23.2 MPa. Surface treatment with aluminum oxide sandblasting allowed a statistically significant increase (p<0.05) in bond strength values. The group treated with Z-Prime Plus achieved (p<0.05) higher bond strength results than the other chemical treatments. Conclusions: The surface mechanical treatment almost doubled the bond strength values. Z-Primer Plus have enhanced bond strength values of composite to zirconia.
- Color matching with conservative porcelain laminate veneers: a case reportPublication . Lampreia, Marina; Oliveira, Sofia; Leitão, JorgeIn aesthetic dentistry, porcelain laminate veneers (PLVs) have demonstrated excellent clinical behavior in terms of periodontal reaction and durability. Of the ceramic systems presently available for the fabrication of PLVs, among the most commonly used are feldspathic porcelain applied via the traditional powder-slurry method, heat-pressed leucite-reinforced ceramics, and CAD/CAMprocessed ceramics. The success of the PLV is greatly determined by the nature of the bond established between the tooth surface and the PLV. For this purpose, silicon oxide etchable ceramics are generally the most reliable. As their glassy phase is selectively dissolved by the acid and the crystals become exposed, an excellent retentive surface is created. Silicon oxide ceramics can be processed according to the pressed technique. This method enhances strength, homogeneity, and fit. All-ceramic systems (eg, OPC, Pentron Laboratory Technologies, Wallingford, CT; Authentic, Microstar Corporation, Lawrenceville, GA; IPS Empress, Ivoclar Vivadent, Amherst, NY), are examples of pressed ceramics obtained from evenly dispersed leucite crystals. This article presents the treatment of severely compromised aesthetics in the anterior region using a combination of tooth whitening and contemporary composite and porcelain restorative materials.
- CommentaryPublication . Luís, Henrique
- Comparison of the third molar maturity index (I3M) between left and right lower third molars to assess the age of majorityPublication . Angelakopoulos, N.; Galić, I.; Pereira, Palmela C.
- Dental age assessment by I 2M and I 3MPublication . Augusto, A.; Pereira, C. PalmelaObjective: Better understanding of dental age assessment may help in cases of age estimation in Forensic Clinics. The first aim was to provide essential information on method reliability for upcoming studies using dental age assessment by second molar index (I2M), and third molar index (I3M) for age estimation on legal ages of 12 - 14 years. The second aim was to document forensic method outcomes of the Demirjian method which has already been used in forensic clinic. Material and methods: Two samples were used for this purpose: for I2M, 633 orthopantomographs (270 females / 363 males), the age range from 7 to 17 years and for I3M, 471 orthopantomographs (253 females / 218 males), the age range from 10 to 23 years, from the database population of Lisbon North University Hospital Center, approved by the Ethic Committee. Results: The I3M cut-off point (1.133) for 12- year- olds obtained better results than the cut-off point stated by the I2M (0.135). Besides, I2M cut-off point (0.001) for 14- year- olds showed better results when compared with the cut-off point (0.705) established by the I3M. Both methods are reliable for the legal age thresholds of 12 and 14 years. However, using I2M and I3M allows us to vary the cut-off value to privilege sensitivities or specificity, depending on which is more appropriate to the intended application. Conclusions: The accuracy (88.94%) of I3M obtained better results for the 12- year- old cut-off point (1.133) and the accuracy (90.21%) of the I2M performed better for the 14- year- old cut-off point (0.001).
- Dental amalgam and antibiotic- and/or mercury-resistant bacteriaPublication . Roberts, M. C.; Leroux, B. G.; Sampson, J.; Luis, H. S.; Bernardo, M.; Leitão, J.Mercury emitted from dental amalgam may select for increased numbers of antibiotic- or mercuryresistant commensal bacteria in patients and increase their risk for bacterial diseases that are resistant to common therapies. We hypothesized that the presence of dental amalgams would increase the level of mercury-, tetracycline-, ampicillin-, erythromycin-, or chloramphenicolresistant oral and urinary bacteria as compared with levels in children receiving composite fillings. Samples were collected at baseline, 3-6 months after the initial dental treatment, and annually for 7 years of follow-up. There were no statistically significant differences between treatment groups in the numbers of bacteria growing on antibiotic- or mercury-supplemented plates. This study provided no evidence that amalgam fillings on posterior teeth influenced the level of antibiotic- or mercury-resistant oral or urinary bacteria as detected by culture.
- Dental hygiene work in a clinical trialPublication . Luís, H. S.; Morgado, I; Assunção, V.; Bernardo, M. F.; Leroux, B.; Martin, M. D.; DeRouen, T. A.; Leitão, J.Dental hygiene activities were developed as part of a randomized clinical trial designed to assess the safety of low-level mercury exposure from dental amalgam restorations. Along with dental-hygiene clinical work, a community programme was implemented after investigators noticed the poor oral hygiene habits of participants, and the need for urgent action to minimize oral health problems in the study population. Objectives: Clinical and community activity goal was to promote oral health and prevent new disease. Community activities involved participants and their fellow students and were aimed at providing education on oral health in a school environment. Methods: Dental hygienists developed clinical work with prophylaxis, sealants application and topical fluoride and implemented the community programme with in-class sessions on oral health themes. Twice a month fluoride mouthrinses and bi-annual tooth brushing instructional activity took place. Participation at dental-hygiene activities, sealed teeth with no need of restoration and dental-plaque-index were measures used to evaluate success of the programme for the participants. Results: Improvement in dental hygiene is shown by the decrease in dental plaque index scores (P < 0.0001); also sealants integrity is achieved in 86.3% of teeth. 888 (13.7%) teeth with sealants had to be restored or were lost. Children participated actively on dental hygiene activities. Teachers became aware of the problem and included oral-health in school curricula. Conclusion: Dental hygiene activities have shown to be helpful to promote dental hygiene, promote oral health and to provide school-age children with education on habits that will be important for their future good health.