Mirella Lindoso Gomes Campos

Association of hyaluronic acid with a collagen scaffold may improve bone healing in critical-size bone defects.

OBJECTIVES To evaluate the effects of a 1% hyaluronic acid (HA) gel in combination with an absorbable collagen sponge (ACS) in the healing of critical-size calvaria defects in rats. MATERIAL AND METHODS Thirty-two adult Wistar rats were used. Two 5-mm-diameter critical-size defects were created and the treatments were randomly distributed as follows: (1) 1% HA; (2) 1% HA gel-soaked ACS; (3) control (blood clot); and (4) ACS. The animals were sacrificed 60 days post-surgery, when biopsies were collected and processed for histology and histometric analysis. Bone fill was measured as the difference between the initial and the final defect sizes. Non-parametric tests were used to analyze differences between treatments (α=1%) and a t-test for body weight gain in each treatment group (α=5%). RESULTS Histological analysis showed bone formation on the edges of the defects, although very limited, and a thin layer of connective tissue occupying the midportion of the defects in the control and the ACS groups. Defects filled with a 1% HA gel and 1% HA gel+ACS had a thicker layer of connective tissue and more new bone formed in the margins of the defects. Linear histometric measures showed no significant differences in the initial defect sizes between the groups (P>0.05). The association 1% HA gel+ACS (0.96 ± 0.14 mm) had significantly greater bone fill than the control (0.5 ± 0.02 mm) and ACS (0.56 ± 0.05 mm)-treated groups (P=0.0043 and 0.0173, respectively). Treatment with a 1% HA gel (0.7 ± 0.14 mm) showed no significant differences when compared with the other treatments. CONCLUSION Within the limits of this study, a 1% HA gel associated with a collagen scaffold can improve new bone formation in critical-size defects. However, this treatment never resulted in complete closure of the defects and healing in the major portion of the defects was characterized by fibrous tissue.

Histometric evaluation of bone around titanium implants with different surface treatments in rats exposed to cigarette smoke inhalation

OBJECTIVES There is a lack of histological information about the influence of cigarette smoke on bone around surface-treated implants. The aim of the present study was to test the influence of titanium surface treatment on osseointegration in animals that were exposed to intermittent cigarette smoke inhalation. MATERIAL AND METHODS Twenty-two male Wistar rats were used. One tibia, chosen at random, received a machined titanium implant (MI) while the other received an aluminum oxide-blasted surface implant (ABI). The animals were randomly assigned to one of the following groups: Group 1 - control (n=11) and Group 2 - intermittent cigarette smoke inhalation (n=11). Sixty days after surgery, the animals were sacrificed. The degree of bone-to-implant contact (BIC), bone filling (BF) within the limits of the threads of the implants and bone density (proportion of mineralized bone in a 500-mum-wide zone lateral to the implant - BD) were measured in the cortical (zone A) and cancellous bone (zone B) areas. RESULTS Data analysis showed significant differences when comparing the groups and implant surfaces in both zones for BIC (two-way ANOVA -P<0.05). The two groups presented higher BIC mean values for ABI, when compared with MI (P<0.05). In group 2, cigarette smoke inhalation negatively affected BF in both zones (P<0.05). Group 2 presented a significantly decreased BD in both zones (P<0.05). No statistically significant differences were observed between surfaces in any of the groups for BD. CONCLUSION Within the limits of the present study, it can be concluded that the aluminum oxide blast surface treatment may increase the degree of BIC but cannot overcome the detrimental effect of tobacco smoke on bone around titanium implants.

Histometric Analysis of the Effect of Enamel Matrix Derivative on the Healing of Periodontal Defects in Rats With Diabetes

BACKGROUND Diabetes mellitus (DM) involves metabolic changes that can negatively influence periodontal tissues, resulting in impaired periodontal repair. There is a lack of information about the outcomes of regenerative approaches under the influence of DM. Enamel matrix derivatives (EMDs) have been used in periodontal regenerative procedures, resulting in improvement of clinical parameters. Thus, the aim of this histomorphometric study is to evaluate the healing of periodontal defects after treatment with EMD under the influence of DM. METHODS Twenty Wistar rats were randomly assigned to two groups: group 1 (G1): DM was induced with a single intraperitoneal injection of streptozotocin (STZ) (n = 10); group 2 (G2): rats were not exposed to STZ (n = 10). Seven days after DM induction, bilateral fenestration defects were created at the buccal aspect of the first mandibular molar. After the surgeries, the defects of each animal were randomly assigned to two subgroups: non-treated (control) and treated with EMD. The animals were euthanized 21 days later, and the percentage of defect fill (DF), newly formed bone density (BD), and new cementum formation (NCF) were histometrically assessed. The number of osteoclasts was determined by tartrate-resistant acid phosphatase. Weight and blood glucose were also analyzed. Mann-Whitney U test was used for comparison among groups and Wilcoxon test for comparison between the start and end times (weight and blood glucose) and between treatments (NCF and number of osteoclasts). One-way analysis of variance was used to assess DF and BD. Tukey test was used when the analysis of variance test detected significant differences (α = 5%). RESULTS G1 (DM) showed less DF and BD compared with G2. EMD provided an increased DF in both groups and enhanced BD and NCF only in G2. The number of TRAP-positive osteoclasts was significantly higher in EMD-treated sites of G1. CONCLUSIONS DM may produce a significant detrimental effect on BD. EMD may provide greater DF under diabetic or normal conditions; however, it may not significantly increase NCF in animals with DM.

Cigarette smoke inhalation increases the alveolar bone loss caused by primary occlusal trauma in a rat model.

BACKGROUND AND OBJECTIVE Occlusal trauma (OT) and smoking are both factors that alter alveolar bone metabolism and therefore could synergistically act on alveolar bone loss. The aim of this experimental study was to evaluate the influence of short-term cigarette smoke inhalation (CSI) on inter-radicular alveolar bone loss promoted by primary OT in a rat model. MATERIAL AND METHODS Forty-eight animals were randomly assigned to one of three groups based on treatment type: OT + CSI (n = 16), animals were exposed to CSI three times per day, for 8 min per exposure, and they concomitantly received unilateral vertical augmentation creating an occlusal interference inducing experimental OT; OT (n = 16), animals received only unilateral vertical augmentation; negative control (NC; n = 16), animals maintained for equal periods to achieve periodontal baseline values of periodontal ligament dimension. Each group was divided into two subgroups (n = 8) based on treatment length: 7 or 14 d. RESULTS After 7 d, the OT + CSI group exhibited significantly higher bone loss compared to the NC group (p = 0.0022). After 14 d, the OT (p < 0.0001) and OT + CSI (p < 0.0001) groups presented significantly higher bone loss compared to the NC group, and OT + CSI resulted in significantly higher bone loss than OT alone (p = 0.0241). The number of tartrate-resistant acid phosphatase-positive cells on the linear surface of the bone crest after 7 d was significantly higher in the OT + CSI group as compared to the NC and OT groups (p < 0.0001 and p = 0.0045, respectively) and remained significantly higher in the OT + CSI group after 14 d, compared to the OT group (p < 0.0001). CONCLUSION Short-term CSI increases early bone loss in association with OT after 7 d, and this worsens in severity after 14 d of exposure.

The Impact of Cigarette Smoke Inhalation on the Outcome of Enamel Matrix Derivative Treatment in Rats: Histometric Analysis

BACKGROUND Tobacco use is the most significant risk factor of periodontal disease. Clinical evidence has demonstrated that tobacco may negatively influence the results after surgical and non-surgical periodontal therapy. Enamel matrix derivative (EMD) have been used in periodontal regenerative procedures resulting in improvement of clinical parameters. The effect of EMD in the presence of tobacco compounds is unclear. Thus, the aim of the present study is to evaluate the impact of cigarette smoke inhalation (CSI) on the results of EMD treatment. METHODS Twenty-two Wistar rats were assigned to two groups: Group 1, CSI (n = 11); Group 2, non-exposed (n = 11). Thirty days after initiation of CSI, fenestration defects were created at the buccal aspect of the first mandibular molar. The study followed a split-mouth design. After the surgeries the defects were randomly assigned to two subgroups: non-treated control and treated with EMD. The animals were sacrificed 21 days later and the percentage of defect fill, density of newly formed bone, and new cementum formation were histometrically assessed. The number of osteoclasts was determined by tartrate-resistant acid phosphatase. RESULTS CSI was associated with less bone density compared to the non-exposed group. EMD provided an increased defect fill and new cementum formation in both groups. The number of tartrate-resistant acid phosphatase-positive osteoclasts was significantly higher in the CSI non-treated control group compared to the non-treated control of the non-exposed animals. CONCLUSIONS EMD may provide increased defect fill and cementum formation in the presence or absence of CSI. However, tobacco smoke produced a detrimental effect on bone healing when density of newly formed bone was considered.

Outcome of Enamel Matrix Derivative Treatment in the Presence of Chronic Stress: Histometric Study in Rats

BACKGROUND Psychologic stress and clinical hypercortisolism have been related to direct effects on bone metabolism. However, there is a lack of information regarding the outcomes of regenerative approaches under the influence of chronic stress (CS). Enamel matrix derivative (EMD) has been used in periodontal regenerative procedures, resulting in improvement of clinical parameters. Thus, the aim of this histomorphometric study is to evaluate the healing of periodontal defects after treatment with EMD under the influence of CS in the rat model. METHODS Twenty Wistar rats were randomly assigned to two groups; G1: CS (restraint stress for 12 hours/day) (n = 10), and G2: not exposed to CS (n = 10). Fifteen days after initiation of CS, fenestration defects were created at the buccal aspect of the first mandibular molar of all animals from both groups. After the surgeries, the defects of each animal were randomly assigned to two subgroups: non-treated control and treated with EMD. The animals were euthanized 21 days later. RESULTS G1 showed less bone density (BD) compared to G2. EMD provided an increased defect fill (DF) in G1 and higher BD and new cementum formation (NCF) in both groups. The number of tartrate-resistant acid phosphatase-positive osteoclasts was significantly higher in G1 when compared to G2 and in EMD-treated sites of both groups. CONCLUSIONS CS may produce a significant detrimental effect on BD. EMD may provide greater DF compared to non-treated control in the presence of CS and increased BD and NCF in the presence or absence of CS.

Zygomatic Implant Subjected to Immediate Loading for Atrophic Maxilla Rehabilitation

As life expectancy increases, a larger number of elderly people require dental health care attention for implant-supported rehabilitation, with the aim of restoring the function and aesthetics of the oral cavity. Most of these patients have lost their teeth long time ago, causing a severe bone resorption and maxillary sinus pneumatization. Therefore, the current study aims to demonstrate, through the description of the clinical case, the treatment with zygomatic implants as an option for treating severely atrophic maxillas. In this clinical study, the patient presented, in the clinical and image evaluation, severe alveolar bone atrophy, with height and thickness loss, in addition to a high-level pneumatization of the maxillary sinus, bilaterally. The classical zygomatic fixation technique was suggested, with 2 anterior conventional implants and 2 zygomatic implants in the posterior region with the placement of implant-supported prosthesis with immediate loading. The patient was monitored for 7 years and did not present pain complaints, absence of infection, or implant loss. Based on this clinical case study, it was concluded that the zygomatic implants are satisfactory options to aid the implant-supported rehabilitation of atrophic maxillas.As life expectancy increases, a larger number of elderly people require dental health care attention for implant-supported rehabilitation, with the aim of restoring the function and aesthetics of the oral cavity. Most of these patients have lost their teeth long time ago, causing a severe bone resorption and maxillary sinus pneumatization. Therefore, the current study aims to demonstrate, through the description of the clinical case, the treatment with zygomatic implants as an option for treating severely atrophic maxillas. In this clinical study, the patient presented, in the clinical and image evaluation, severe alveolar bone atrophy, with height and thickness loss, in addition to a high-level pneumatization of the maxillary sinus, bilaterally. The classical zygomatic fixation technique was suggested, with 2 anterior conventional implants and 2 zygomatic implants in the posterior region with the placement of implant-supported prosthesis with immediate loading. The patient was monitored for 7 years and did not present pain complaints, absence of infection, or implant loss. Based on this clinical case study, it was concluded that the zygomatic implants are satisfactory options to aid the implant-supported rehabilitation of atrophic maxillas.

ANÁLISE DE SOBRECARGAS ADQUIRIDAS POR CUIDADORES E SEUS PACIENTES COM COMPLICAÇÕES NEUROLÓGICAS ANTES E APÓS UM PROGRAMA DE ORIENTAÇÕES

Caregivers support people in need, but most start working with little or no instruction. The project “Functionality and quality of life of patients with neurological complications and their caregivers (relatives)” was linked to the Institutional Program of University Scholarships. Four caregivers and patients assisted by the physiotherapy clinic of the State University of the North of Parana underwent an initial and final evaluation and a 10-week program about patients´ care at home. The study aimed at evaluating the quality of life, self-esteem and burnout syndrome of patients with neurological complications and their caregivers, before and after a guideline program. It was found that the quality of life was impaired even after the program, self-esteem presented a mean score before and after the orientations (15.5 to 14 for the caregivers and 16.3 to 15.5 for the patients), and a lower influence of burnout after the intervention, decreasing 6.7% of the score.

Evaluation of bone loss due to primary occlusal trauma in two experimental models of occlusal overload

Introduction Primary occlusal trauma (OT) is an injury of the periodontium with normal height as a result of occlusal forces which exceed their adaptive capacity. Objective To evaluate, histometrically, the alveolar bone loss in the furcation region of rats experimentally submitted to 2 models of occlusal overload. Material and method 45 animals randomly divided into 3 groups: Occlusal Interference (OI, n = 15) - fixing an orthodontic wire segment on the occlusal surface of the first lower molar; Occlusal Overload (OO, n = 15) - wearing of the cusps of the lower contralateral molars, the second and third molars next to the first molar that had its dimensions maintained; Negative Control (NC, n = 15) - evaluation of the initial dimensions of the periodontal ligament (PL). Five animals / group were sacrificed after 14, 21 and 28 days. Result Intergroup evaluation showed significant bone loss in OI (p 0.05). The thickness of the PL remained stable in NC (p>0.05). Conclusion OI and OO were effective in the experimental reproduction of OT, and OI promoted greater alveolar bone loss compared to OO, showing that the impact of occlusal overload in OI increased the extent of the OT injury.