Clinical and metabolic changes after conventional treatment of type 2 diabetic patients with chronic periodontitis

BACKGROUND: The aim of this study was to compare the response to conventional periodontal treatment between patients with or without type 2 diabetes mellitus from a clinical and metabolic standpoint. METHODS: A prospective, parallel, comparative longitudinal clinical study was performed between type 2 diabetics and non-diabetics with moderate generalized chronic periodontitis. The study period was 6 months. Conventional periodontal scaling and root planing were performed, and the response to this treatment was compared between the groups at 3 and 6 months, measuring the plaque index, bleeding on probing, probing depth, level of clinical attachment, and gingival recession. In the diabetic patients, the clinical response was related to measurements of HbA1c and glucose in blood at 3 and 6 months. RESULTS: An improvement in all clinical variables was observed, with no statistically significant differences between the groups, with the exception of probing depth (P <0.0207). The improvement observed in blood HbA1c levels confirmed a positive metabolic response to periodontal treatment, with a lower value for this variable at each measurement time. CONCLUSIONS: Both groups of patients showed a clinical improvement after basic non-surgical periodontal treatment. The diabetic patients showed improved metabolic control (lower HbA1c) at 3 and 6 months after periodontal treatment.     

A preliminary protocol for multi-professional centers for the determination of signs and symptoms of temporomandibular disorders

The objective of the present study was to test a protocol for the quantification of the frequency and severity of signs and symptoms of temporomandibular disorders (TMD) according to patient perception during two phases of investigation. The protocol was developed based on the signs and symptoms most frequently reported in the literature and on the circumstances in which they produce discomfort. Eighty-four patients diagnosed with TMD by functional examination of the masticatory system responded to the protocol questions and indicated the severity of signs and symptoms using an eleven point numerical scale (Phase 1). Forty-two patients were fitted with an occlusal splint (treated group) and the remaining participants did not use a splint (control group). The protocol questions were asked after 50 days of treatment (Phase 2). Based on the results of nonparametric statistical analysis, the incidence of signs and symptoms was high in Phase 1 and significant, with no difference between the groups, whereas the treated and control groups differed in Phase 2. A comparison between Phases 1 and 2 showed that only the treated group presented a reduction in the severity of signs and symptoms. The study showed that using this protocol, it is possible to define the frequency and severity of symptoms as well as the effect of the treatment. The advantage of this protocol is that it would complement the data obtained using clinical examination with information provided by the patient in a measurable manner.     

Dominant form of arthrogryposis multiplex congenita with limited mouth opening: a clinical and imaging study

AIMS: Arthrogryposis multiplex congenita (AMC) is characterized by congenital contractures and joint deformities, but there are only a few reports of temporomandibular joint (TMJ) involvement. The objective of this investigation was to study the cause of limited mouth movement in this disease. MATERIALS AND METHODS: Four individuals from a family affected by AMC over 5 generations were examined clinically and by magnetic resonance imaging (MRI) and 3-dimensional computerized tomography (3D-CT). RESULTS: The CT scans of the 4 individuals showed hyperplasia of the coronoid process protruding into the infratemporal fossa in 2 of them and cranially to the zygomatic arch in the other 2; the hyperplasia was associated with mechanical limitation of the mouth opening. The MRI showed a disc displacement with reduction in 1 patient and a disc displacement without reduction in another; disc displacement could not be evaluated because of the limited mouth opening in the other 2. The condyle-disc complex of these last 2 individuals could only rotate. The MRI on T2-weighted images showed disc hyposignal in all cases but no alterations in the masticatory muscle tissue. The pedigree of the family suggests an autosomal dominant form of inheritance. CONCLUSIONS: The restriction of mouth opening in the 4 individuals affected by AMC was likely due to osseous dysplasia.     

Light shielding effect of overlaying resin composite on the photopolymerization cure kinetics of a resin composite and a dentin adhesive.

OBJECTIVES: The purpose of this study was to simultaneously determine the impact of exposure times and incremental resin composite overlaying thickness on the cure kinetics of a light activated composite and a dentin adhesive at selected depths of a simulated restoration. METHODS: Levels and kinetics of polymerization of a light activated resin composite (Z250, 3M-ESPE) and dentin adhesive (Excite, Ivoclar) cured with a halogen light unit (Demetron, Kerr, USA) operating at low/medium intensity (500 mW/cm2) for different exposure durations (20 and 60 s) were measured at selected depths (0.3, 0.6 and 1mm) using a modified calorimetric analyzer (DSC 25, METLLER-TOLEDO). RESULTS: Final polymerization levels of materials up to 1mm through the composite are not significantly different while the light shielding effect of incremental resin composite overlaying progressively reduces their reaction rates. SIGNIFICANCE: Prolonged irradiation time at low/medium energies is effective for proper conversion of a resin composite and dentin adhesive; 60 s irradiation time provides the maximum obtainable conversion through the dental resin composite for thicknesses up to 1mm.     

Microtensile bond strength of light- and self-cured adhesive systems to intraradicular dentin using a translucent fiber post

This study evaluated the bond strength of a light- and self-cured adhesive system to different intraradicular dentin areas (cervical, middle and apical thirds). Twenty single-rooted teeth were instrumented and their roots were prepared to receive a #2 translucent fiber post (Light Post). The root canals were irrigated with 0.5% sodium hypochlorite for one minute, rinsed with water and dried using paper tips. The teeth were divided into two groups (n=10): Single Bond [SB] (light-cured) and Scotchbond Multi-Purpose Plus [SBMP] (self-cured). To avoid polymerization of the materials through the root lateral walls, the teeth were placed in a silicone mold and the adhesives applied with a thin microbrush according to manufacturer's instructions. The resin cement, Rely X ARC, was inserted into the root canals using Lentulo burs. The post was then placed and the light-curing procedure was carried out for 40 seconds (+/-500 mW/cm2). The roots were kept in a 100% relative moisture environment for 24 hours and stored in distilled water for an additional 24 hours. Each root was perpendicularly sectioned into 1-mm thick sections, resulting in approximately four slices per region. Dumbbell-shaped slices were obtained by trimming the proximal surfaces of each slice using a diamond bur until it touched the post. The bonded area was calculated, slices were attached to a special device and submitted to microtensile testing at 1 mm/minute crosshead speed. Data were analyzed using ANOVA and Tukey's test. The mean bond strength values (MPa) were: SBMP: cervical=10.8a, middle=7.9b%, apical=7.1bc; SB: cervical=8.1b, middle=6.0c, apical=6.9b. Significant differences were found between adhesive systems only for the cervical third. The cervical region showed higher mean bond strength values than the middle and apical regions (p<0.0001).     

Evaluation of silver methenamine method for nanoleakage

OBJECTIVES: The aim of this study was to evaluate nanoleakage patterns following silver methenamine staining of restorations bonded with a total-etch single bottle system, a self-etching primer system and a total-etch single bottle system after collagen depletion. METHODS: The dentin bonding systems used in this study were Prime and bond 2.1 (PB) and Clearfil SE Bond (CSEB). Cavities were made in grounded labial surfaces of 15 extracted bovine lower incisors, randomly divided into 3 Groups. Group 1 (PB), Group 2 (CSEB) and Group 3 (PB/SH) PB after collagen depletion with sodium hypochlorite (SH). The specimens were restored, sectioned and submitted to silver methenamine staining, polished and observed with low-vacuum back-scattered SEM. One way ANOVA and multiple-comparison Tukey's test were used for statistical analysis of the leakage scores. RESULTS: PB presented significantly greater silver deposition and a distinct pattern when compared to CSEB. No silver deposition was detected for PB after collagen depletion. SIGNIFICANCE: The dentine bonding systems tested were unable to prevent nanoleakage when used according to the manufacturers' instructions; however, CSEB presented a lower level of silver deposition. Collagen depletion prior to PB application may prevent nanoleakage occurrence in dentine walls. Silver methenamine staining may be a useful method for detection of nanoleakage in dentine when the collagen fibrils remain exposed within the hybrid layers.     

Histologic evaluation of the effect of nicotine administration on bone regeneration. A study in dogs

The objective of this study was to investigate the histometric impact of nicotine on bone regeneration of surgically created alveolar ridge defects in dogs. Sixteen mongrel dogs were used. One defect was surgically created unilaterally in the mandible, and left to heal spontaneously. The animals were randomly assigned to one of the following groups: Group 1--control (n = 8) and Group 2--subcutaneous nicotine administration (2 mg/kg) twice a day (n = 8). After 4 months, the animals were sacrificed and the specimens routinely processed for semi-serial decalcified sections. Bone height (BH), bone width (BW), bone density (BD), and bone area (BA) of the newly-formed bone were evaluated. Intergroup analysis (Mann-Whitney rank sum test) showed that regardless of the presence of nicotine, no significant differences were observed regarding bone width (BW), bone area (BA) and bone height (BH) (p > 0.05). On the other hand, it was demonstrated that nicotine administration significantly influenced the proportion of mineralized tissue within the limits of the newly-formed bone (BD) (p < 0.001). Within the limits of the present study, it can be concluded that nicotine might affect but not prevent bone healing in defects left to heal spontaneously.     

Efficacy of bisphosphonates for the control of alveolar bone loss in periodontitis

Periodontal disease is characterized by periodontal bone loss. For this reason, we conducted a study to test the effect of alendronate (ALN), an inhibitor of bone resorption, on alveolar bone mass. A total of 335 patients with periodontal disease (men = 162, women = 173), aged 30 to 79, were randomized to either placebo or ALN 70 mg once weekly. All patients received prophylaxis at baseline, and at 6, 12, and 18 months. Smokers accounted for 62% of patients, and 71% of the patients had severe periodontal disease. The primary efficacy endpoint was the change in alveolar bone loss (ABL). When all subjects were analyzed, 2 years of treatment with alendronate 70 mg once weekly did not significantly change either ABL or alveolar bone density (ABD) relative to placebo. However, in the subgroup of patients with low mandibular bone mineral density (BMD) at baseline, alendronate significantly reduced bone loss relative to placebo (p < 0.01). No such effect was seen in patients with normal baseline mandibular BMD. The overall and upper gastrointestinal safety and tolerability profile of alendronate after 2 years of treatment was very favorable compared to placebo. No cases of osteonecrosis of the jaw were observed. In summary, in patients with periodontal disease receiving prophylaxis, alendronate 70 mg once weekly was well tolerated, but did not have a detectable effect on alveolar bone loss, except in those patients with low mandibular BMD at baseline.     

Ultrastructural and microbiological analysis of the dentin layers affected by caries lesions in primary molars treated by minimal intervention

PURPOSE: The purpose of this in vivo study of primary teeth was to analyze the ultrastructure and microbiology of dentin layers affected by caries lesions before and after restorations with resin-modified glass ionomer. METHODS: Samples of carious dentin from primary teeth removed prior to restoration placement (baseline-0 day) were compared with samples taken after 30 and 60 days. Dentin from 8 primary molars was analyzed by scanning electron microscopy (SEM) and dentin from 22 primary molars was examined microbiologically to compare bacteria (total of viable counts, Streptococcus spp, Streptococcus mutans, Lactobacillus spp, and Actinomyces spp) before and after treatment (30 and 60 days). RESULTS: Baseline caries samples had enlarged dentinal tubules with bacteriol invasion. SEM samples after treatment suggest better tissue organization, with more compact collagen fibers arrangement and narrower dentinal tubules. The number of bacteria decreased in all samples at both 30 (98%) and 60 (96%) days, with all bacteria species showing similar trends. CONCLUSIONS: The minimal intervention approach is very effective to promote beneficial changes in the lesion environment and favorable conditions for the healing process in primary teeth.