Histological evaluation of the repair process of replanted rat teeth after storage in resveratrol dissolved in dimethyl sulphoxide.

BACKGROUND/AIM: The storage media is directly related to the prognosis of avulsed teeth, with resveratrol drawing attention due to its antioxidant and anti-inflammatory proprieties. The aim of this study was to evaluate the repair process in rat teeth following delayed replantation after storage in resveratrol (R) dissolved in dimethyl sulphoxide (DMSO). MATERIALS AND METHODS: The upper right central incisors of 36 rats were divided into 4 groups. In group I, the teeth were extracted and immediately replanted. Group II teeth were stored in 50 mL R+DMSO (0.0512 g/mL), whereas group III teeth were stored in 50 mL pure DMSO, both for a period of 60 minutes. The teeth of group IV were stored dry for 60 minutes. The teeth of groups II, III and IV were then replanted, and the animals were euthanized after 60 days. Longitudinal histological cuts were HE stained for histomorphometric analysis of the periodontal ligament, alveolar bone, cementum and dentin. RESULTS: The analysis of HE stained histological sections showed the following statistical differences: the acute inflammatory process in the epithelial insertion was less prominent in group II than in group III; the organization of the periodontal ligament was better in group I, while the intensity and extension of acute inflammation in the periodontal ligament were better in group I, and worse in group III; the chronic inflammatory infiltrate was less in groups I and IV, and the depth and extent of resorption, as well as the repair of root resorption, were better in group I. CONCLUSIONS: Storage in R+DMSO solution did not inhibit root resorption after delayed replantation in rat teeth. It is concluded that pure DMSO is not a suitable transport medium for avulsed teeth.

Histomorphometric analysis of the healing process after the replantation of rat teeth maintained in bovine milk whey and whole milk.

BACKGROUND/AIM: In cases of tooth avulsion, a minimal extra-alveolar dry storage period or the use of a suitable storage medium is crucial to maintaining the vitality of the periodontal ligament. Whey has similar properties to milk and has therefore been investigated as a storage medium for avulsed teeth. The aim of this study was to evaluate the repair process after replantation of rat teeth kept in whey and whole milk. MATERIALS AND METHODS: Thirty-six male rats were divided into four groups of nine animals. The upper right incisor was extracted under general anesthesia. In Group I, the teeth were immediately replanted without treatment (positive control). In Group II, the teeth were stored in 50 mL of sweet whey. In Group III, the teeth were kept in 50 mL of long-shelf-life whole milk (UHT, Parmalat® ). In Group IV, the teeth were kept dry (negative control). After 60 minutes, the teeth in Groups II, III, and IV were replanted into their sockets. The animals were subjected to euthanasia 60 days after replantation. The specimens were stained with hematoxylin and eosin for histomorphometric analysis. RESULTS: The organization of the periodontal ligament in Group II (whey) was similar to that in Groups I (immediate replantation) and III (whole milk) (P > .05). However, some specimens in this group exhibited periodontal fibers inserted into the bone and cementum throughout the entire length of the periodontal ligament. This occurred in the group submitted to immediate replantation, whereas this histological aspect was not seen in whole milk group. Group IV (late replantation) had a higher rate of root resorption. Regarding the root repair process, it was expected that Group I (immediate) would demonstrate more favorable repair than the other groups. However, Group III (whole milk) had better results when compared to Groups II (whey) and IV (late) (P < .05). CONCLUSION: Whey and whole milk achieved similar results and were adequate storage media for avulsed teeth.

Effect of recombinant PDGF-BB on bone formation in the presence of ß-tricalcium phosphate and bovine bone mineral matrix: a pilot study in rat calvarial defects.

BACKGROUND: Supplementation of bone substitutes with recombinant platelet-derived growth factor-BB (PDGF-BB) can enhance bone regeneration. The aim of the study was to evaluate the effect of PDGF-BB on bone formation in the presence of ß-tricalcium phosphate and bovine bone mineral matrix in a rat calvaria defect model. METHODS: The authors examined 5 mm rat calvarial defects treated with ß-tricalcium phosphate (TCP) or demineralized bovine bone mineral (DBBM) with and without 0.3 mg/ml recombinant PDGF-BB. Calvaria defects were randomly divided into the following treatment groups (n = 5); TCP; TCP plus PDGF-BB; DBBM; DBBM plus PDGF-BB; and untreated empty control. After 45 days, bone formation was evaluated by histomorphometry and fluorescence microscopy. RESULTS: The authors report that the area of newly formed bone was similar between the empty controls and the two bone substitutes, TCP and DBBM. Supplementation of TCP and DBBM with PDGF-BB had no significant impact on bone formation. Fluorochrome staining revealed no visible changes in the pattern of bone formation in defects filled with TCP and DBBM, irrespective of PDGF-BB. Furthermore, supplementation with PDGF-BB did not influence biomaterial degradation. CONCLUSIONS: The authors concluded that PDGF-BB had no impact on bone formation and degradation of bone substitutes in the respective rodent models. Thus, possible beneficial effects of PDGF-BB may require other model situations.

Full-Mouth Rehabilitation Using All-Ceramic Restorations.

The scientific and technological advancement of cosmetic dentistry has improved metal-free ceramic systems for fixed prosthodontics as well as porcelain veneers, making them an excellent treatment option for delivering superior cosmetic results. The authors present a clinical case of full-mouth rehabilitation using all-ceramic restorations with porcelain metal-free unit crowns in the maxilla, and porcelain veneers from the left inferior premolar to the right inferior premolar. Using this approach, they were able to achieve an excellent esthetic and functional result for the patient.

Histometric analysis and topographic characterization of cp Ti implants with surfaces modified by laser with and without silica deposition.

Biologic behavior of the bone tissue around implants with four different surfaces was evaluated. The surfaces were: modified by laser (LS); modified by laser with sodium silicate deposition (SS); and commercially available surfaces modified by acid etching (AS) and machined surface (MS). Topographic characterization of the surfaces was performed by scanning electron microscopy (SEM)- energy dispersive X-ray spectrometry (EDX) before experimental surgery. Thirty rabbits received 60 implants in their right and left tibias, 1 implant of each surface being placed in each tibia. The analyzed periods were 4, 8, and 12 weeks postoperatively. Histometric analysis was performed evaluating bone interface contact (BIC) and bone area (BA). The results obtained were submitted to the analysis of variance and the Tukey t-test. The elemental mapping was evaluated by means of SEM at 4 weeks postoperatively. The topographic characterization showed differences between the analyzed surfaces. Generally, the BIC and BA of LS and SS implants were statistically higher than those of AS and MS in most of the analyzed periods. Elemental mapping showed high peaks of calcium and phosphorous in all groups. Based on the present methodology, it may be concluded that experimental modifications LS and SS accelerated the stages of the bone tissue repair process around the implants, providing the highest degree of osseointegration.

Comparative in vivo study of commercially pure Ti implants with surfaces modified by laser with and without silicate deposition: biomechanical and scanning electron microscopy analysis.

The purpose of this study was to evaluate commercially pure titanium implant surfaces modified by laser beam (LS) and LS associated with sodium silicate (SS) deposition, and compare them with machined surface (MS) and dual acid-etching surfaces (AS) modified. Topographic characterization was performed by scanning electron microscopy-X-ray energy dispersive spectroscopy (SEM-EDX), and by mean roughness measurement before surgery. Thirty rabbits received 60 implants in their right and left tibias. One implant of each surface in each tibia. The implants were removed by reverse torque for vivo biomechanical analysis at 30, 60, and 90 days postoperative. In addition, the surface of the implants removed at 30 days postoperative was analyzed by SEM-EDX. The topographic characterization showed differences between the analyzed surfaces, and the mean roughness values of LS and SS were statistically higher than AS and MS. At 30 days, values removal torque LS and SS groups showed a statistically significant difference (p < 0.05) when compared with MS and AS. At 60 days, groups LS and SS showed statistically significant difference (p < 0.05) when compared with MS. At 90 days, only group SS presented statistically higher (p < 0.05) in comparison with MS. The authors can conclude that physical chemistry properties and topographical of LS and SS implants increases bone-implant interaction and provides higher degree of osseointegration when compared with MS and AS.

The effect of BMP-2 on the osteoconductive properties of ß-tricalcium phosphate in rat calvaria defects.

Bone formation in critical-sized calvaria defects is strongly dependent on the osteoconductive properties of grafts. It remains a matter of controversy whether biomaterials can replace autografts and whether the supplementation of biomaterials with Bone Morphogenetic Proteins (BMPs) is necessary to enhance bone formation. We examined rat calvaria critical-sized defects (5-mm-diameter) treated with ß-tricalcium phosphate (TCP; Cerasorb® M), polylactic and polyglycolic acid gel (PLA/PGA; Fisiograft®) and calcium phosphate cement (CPC; Norian® CRS®), either alone or in the presence of 5 µg of BMP-2 after 45 days. Autografts and untreated defects served as controls. Bone formation was evaluated based on µCT analysis, histomorphometric analysis and fluorescence analysis. We report that TCP supported bone formation more efficiently than did autografts. Bone formation in the presence of TCP alone reached a maximal level, as BMP-2 supplementation failed to enhance bone formation. By contrast, no significant difference in bone formation was observed when PLA/PGA and CPC were compared to autografts. Moreover, the presence of BMP-2 did not substantially change the osteoconductive properties of PLA/PGA or CPC. We conclude that the osteoconductive properties of TCP are superior to those of autografts and that TCP does not require BMP-2 supplementation. Our findings also show that the decreased osteoconductive properties of PLA/PGA and CPC cannot be overcome by BMP-2 supplementation in rat calvaria defects.