A quantitative method of measuring the microleakage of thermocycled or non-thermocycled posterior tooth restorations

This study quantified microleakage in restorations made with three packable resin composites-Solitaire, SureFil and P60; one hybrid resin composite-Z250 and an amalgam-Dispersalloy, with or without the thermocycling process. Sixty sound, freshly extracted human molars were sectioned mesiodistally, creating buccal and lingual blocks. One hundred blocks with the flattest surface were selected. Cylindrical cavities with a diameter of 1.85 +/- 0.05 mm and a depth of 1.5 mm were prepared with a special diamond bur. The blocks were randomly assigned to 10 test groups (n = 10): five restorative materials and two thermal stress groups (thermocycled groups at 3,000 cycles at 5 degrees C and 55 degrees C with a dwell time of one minute at each temperature, or non-thermocycled). After the thermocycling test, the samples were immersed in 2% methylene blue for 12 hours. The samples were ground and the powder prepared for analysis in an absorbance spectrophotometer. All the results were statistically analyzed by the Kruskal-Wallis test and the Mann Whitney test. For the non-thermocycled groups, the means (microg/ml) of microleakage were: Amalgam-4.279 (a); Solitaire-4.148 (ab); Z250-3.418 (abc); P60-3.184 (bc); SureFil-2.890 (c). For the thermocycled groups, the means were: Amalgam-7.572 (a); Solitaire-5.471 (a); Z250-4.330 (ab); P60-3.418 (bc) and SureFil-2.779 (c). Thermocycling analysis showed no significant differences between the thermocycled and non-thermocycled groups for each material tested. It was concluded that no test material prevented microleakage. Only SureFil and P60 showed leakage means significantly lower than amalgam, with SureFil showing lower leakage than Solitaire. P60 only showed lower leakage than Solitaire in the thermocycled groups and Z250 showed results similar to the others materials.     

Relationships between clinical attachment level and spine and hip bone mineral density: data from healthy postmenopausal women

BACKGROUND: There are physiological reasons to expect an association between bone mineral density of the spine and hip and attachment loss. To this point, however, most studies have found no correlation. METHODS: The 135 patients in this report were part of a randomized controlled trial of estrogen replacement. All patients were in good oral health at entry and received annual oral prophylaxis as part of the study. Standard probing measurements were made with a pressure sensitive probe at 6 sites on each tooth. Bone mineral density was measured with dual-energy x-ray absorbtiometry at the lumbar spine (anterior-posterior and lateral) and proximal femur (neck, trochanter, intertrochanter, Ward's triangle, and total area). These procedures were performed at baseline and at annual intervals for 3 years. RESULTS: Correlations between cross-sectional measurements of clinical attachment level and bone mineral density were very weak, and did not approach statistical significance (-0.06 < or =r < or =0.10, 0.15 < or =P < or =0.75). A few somewhat stronger correlations were found between longitudinal changes in bone mineral density and attachment (-0.20 < or = r < or =-0.02, 0.02 < or = P < or =0.81). Although the correlations in the longitudinal changes were weak, they were consistently in the direction of greater bone mineral density being associated with less attachment loss. CONCLUSIONS: There is no clear association between clinical attachment level and bone mineral density of the lumbar spine and proximal femur, whether examined on a cross-sectional or longitudinal basis. Patterns in the data suggest there may be a weak association in the longitudinal changes.     

Age-related changes in human sublingual glands: a post mortem study

OBJECTIVES: To analyse age- and gender-related microscopic changes in sublingual glands obtained from human cadavers. STUDY DESIGN: One hundred eighty six human sublingual glands were obtained from 93 autopsies. Approximately five individuals of each gender per decade of life were allocated to three age groups: group I (0-30 years, n=26); group II (31-60 years, n=32) and group III (61-90 years, n=35). The specimens were fixed in 10% formalin and submitted to routine histological processing, and sections were stained with hematoxylin and eosin. RESULTS: Significant differences with increasing age were observed for the following microscopic aspects: acinar atrophy (r=0.26, p=0.0115); replacement of parenchyma by fibrous tissue (r=0.79, p<0.0001) and/or adipose tissue (r=0.63, p<0.0001); oncocytosis (r=0.61, p<0.0001); duct-like structures (chi(2)=14.68, p=0.0006) and congested blood vessels (chi(2)=7.18, p=0.0276). The mononuclear infiltrate changed from focal to diffuse with age (H=8.47, p=0.0144). No significant differences were observed between genders. CONCLUSIONS: The aging process starts with acinar atrophy, followed by the presence of duct-like structures and ends with the replacement of the parenchyma by fibrous and/or adipose tissue. The mononuclear infiltrate changes from focal to diffuse. No difference in the aging of the sublingual glands is observed between men and women.     

An in vitro model to investigate filling of lateral canals

Aims of this work were to examine lateral canals in extracted teeth, to propose a new technique to produce artificial lateral canals, and to compare two obturation techniques. Cleared roots were examined to record measure and shape of lateral canals. Artificial lateral canals were prepared on human demineralized teeth before final clearing. Specimens were divided in two groups: canals of group 1 were filled with Schilder's technique, canals of group 2 were filled with vertical compaction with apical backfilling. Stereomicroscopic analysis of lateral canal filling revealed lower filling rates in apical canals compared to coronal ones and higher filling rates with "vertical compaction with apical backfilling" compared to Schilder's group. The tested procedure appears to be a reliable technique to obtain standardized lateral canals and to compare filling procedures.     

Implant-Supported Rehabilitation of the Severely Atrophic Maxilla: A Clinical Report

Implant-supported rehabilitation in the posterior maxillary region presents a series of challenges because of the possibility of increased pneumatization of the maxillary sinus after dental loss. In cases where significant maxillary bone resorption has occurred, efforts center on maximizing the use of the remaining bone to afford primary stability to the implants. This clinical report describes a patient with extreme maxillary atrophy for whom fixed rehabilitation supported on 8 implants was accomplished. A zygomatic implant, a pterygomaxillary implant, and 2 implants mesial and distal to both canine eminences were placed. This rehabilitation was accomplished with a less invasive technique and in a much shorter time period compared to a sinus lift procedure. One year after prosthetic loading, the clinical and radiological results remain satisfactory.     

Transverse craniofacial features and their genetic predisposition in families with nonsyndromic unilateral cleft lip and palate.

OBJECTIVE: The purpose of this study was to evaluate the transverse craniofacial form in families with nonsyndromic cleft lip and palate (NSCLP). It was hypothesized that affected as well as noncleft NSCLP family members are characterized by a common array of craniofacial features that differ from the general population. DESIGN: This was a prospective cross-sectional investigation that included affected children with NSCLP and their noncleft parents and siblings. PATIENTS, PARTICIPANTS: A total of 114 subjects (14 affected girls, 17 affected girls, 15 unaffected male siblings, 10 unaffected female siblings, 29 unaffected biological mothers, and 29 unaffected biological fathers) were included. Subject records comprised of posteroanterior cephalometric radiographs obtained from all 114 subjects. MAIN OUTCOME MEASURES: The width of midfacial structures, including the orbit and nose, was increased in NSCLP families, compared with published norms. Interestingly, the face was disproportionally wider in relation to total facial height. The transverse craniofacial form of children with or without clefts significantly correlated with that of their parents. Mothers displayed strong correlation with their affected and unaffected sons, whereas fathers correlated to their daughters, suggesting a possible sex-linked developmental influence. CONCLUSION: Better understanding of the genetic inheritance of craniofacial features associated with cleft lip and palate may ultimately contribute to the development of cleft risk assessment methods.     

Oral diseases and conditions throughout the lifespan. II. Systemic diseases

Oral diseases may affect general health and many systemic disorders have oral manifestations and implications for dental treatment. This article reviews examples of the oral manifestations of systemic diseases, including oral cancer, diabetes mellitus, and infection from HIV. In addition, the plausible link between periconceptional use of folic acid by the mother and the risk of facial clefts is reviewed. The possible associations between oral infections, specifically periodontal diseases, and both cardiovascular disease and the delivery of preterm low birthweight infants also are reviewed. These and other associations present challenges to dentists, who must evaluate the scientific evidence supporting the associations or alleged causality and select effective treatment options. Both of these challenges require in-depth knowledge of the scientific method, criteria to establish causality, and evaluation of the merit of possible treatment options; in turn, these requirements identify dentists as medical professionals who utilize prevention as the first option in health care, use oral tissues and saliva to diagnose systemic diseases, rely on medical facilities to order laboratory tests, and diagnose and treat patients in close collaboration with their medical colleagues.     

Morphometric and microscopic evaluation of the effect of solution of acetazolamide as an intracanal therapeutic agent in late reimplanted rat teeth

Abstract –  The use of substances that inhibit root resorption may be an alternative for cases of unsuccessful reimplants. Hence, the purpose of this study was to test a solution of acetazolamide, a resorption inhibitor, as an intracanal therapeutic agent for late reimplanted teeth. Thirty rat maxillary right central incisors were avulsed and kept dry for 30 min. The teeth were instrumented, and the root surfaces treated with 1% hypochlorite solution followed by application of 2% sodium fluoride. Thereafter, the teeth were divided into two groups according to the intracanal dressing: Group I, solution of acetazolamide and Group II, calcium hydroxide paste. Teeth were then reimplanted in their respective sockets. The animals were killed at 15, 30, and 60 days after reimplantation and the samples processed for morphometric and microscopic analysis. The results showed that calcium hydroxide paste limited root resorption, even though not avoiding it. In contrast, no root resorption was observed after 60 days in the acetazolamide group, confirming the efficacy of the substance in inhibiting root resorption.     

A comparison between enamel matrix derivative and a bioabsorbable membrane to enhance healing around transmucosal immediate post-extraction implants

BACKGROUND: This clinical report compares the use of an enamel matrix derivative (EMD) and bioabsorbable barrier membrane to enhance healing following the immediate placement of transmucosal implants into extraction sockets. METHODS: Thirty-two adult patients scheduled for tooth replacement with dental implants agreed to participate. Following the insertion of a transmucosal implant into the extraction site, the subjects were assigned to one of two treatment alternatives of the remaining bone defects around the implants: 1) the residual bone defects were filled with EMD (EMD group) or 2) the residual bone defects were covered with a bioabsorbable membrane (membrane group). Flaps were then coronally positioned around implant cover screws. Patients followed weekly maintenance recalls for the first 6 weeks and then monthly recalls until the final prosthetic restoration was completed (after 6 months). The treatment outcome was evaluated after 12 months by the use of clinical variables. The null hypothesis of no treatment group differences was tested by the use of analysis of variance (ANOVA). RESULTS: At a 12-month follow-up, all of the implants were completely osseointegrated and successfully functioning, showing a success rate of 100%. The membrane group showed a significantly lower mean probing attachment level than the EMD group at proximal (0.60 mm, standard deviation (SD) 0.37 versus 1.19 mm, SD 1.10), buccal (0.80 mm, SD 0.79 versus 1.77 mm, SD 1.16), and lingual sites (0.44 mm, SD 0.52 versus 1.48 mm, SD 1.46). The difference was statistically significant at all sites (P < 0.05). With respect to the position of the soft tissue margin around the implant shoulder, the membrane group showed a consistently higher value than the EMD group at, respectively, proximal (1.30 mm, SD 2.37 versus 1.16 mm, SD 1.0), buccal (0.90 mm, SD 1.29 versus 0.22 mm, SD 1.47), and lingual sites (1.12 mm, SD 1.10 versus 0.55 mm, SD 1.42). CONCLUSIONS: The membrane group obtained more favorable results in terms of both the probing attachment level and peri-implant position of soft tissues compared to the EMD group. The use of a bioabsorbable membrane around immediately placed transmucosal implants enhanced soft and hard tissue healing and might be an advisable treatment choice particularly in areas with high esthetic demands.