ABSTRACT
BACKGROUND: This study evaluated the impact of strontium ranelate on tooth-extraction wound healing in estrogen-deficient and estrogen-sufficient rats. METHODS: Ninety-six Wistar rats (90 days of age) were allocated into one of the following groups: sham-surgery+water (estrogen-sufficient); ovariectomy+water (estrogen-deficient), sham-surgery+strontium ranelate (625 mg/kg/d) (strontium/estrogen-sufficient); ovariectomy+strontium ranelate (625 mg/kg/d) (strontium/estrogen-deficient). Water or strontium ranelate were administrated from the 14th day post-ovariectomy/sham surgery until euthanasia. Maxillary first molars were extracted at 21 days after sham/ovariectomy surgery. Rats were euthanized at 10, 20, and 30 days post-extractions. The following parameters were analyzed inside tooth-extraction wound: proportion of newly formed bone (bone healing/BH), number of cells stained for tartrate-resistant acid phosphatase (TRAP) and immunohistochemical staining for five bone metabolism-related markers (osteocalcin [OCN], osteopontin [OPN], bone sialoprotein [BSP], osteoprotegerin [OPG] and receptor activator of NF-ÐB ligand [RANKL]). RESULTS: The estrogen-deficient group presented lower BH than all other groups at 20 and 30 days post-extraction (P < 0.05). The number of TRAP-stained cells was higher in the estrogen-deficient group than in estrogen-sufficient group at 30 days post-extraction (P < 0.05). The strontium /estrogen-sufficient group exhibited stronger staining for OCN, when compared to the estrogen-sufficient and estrogen-deficient groups (P < 0.05). Both strontium ranelate-treated groups presented higher staining of OPN and BSP than both untreated groups (P < 0.05). The strontium/estrogen-sufficient group demonstrated stronger staining for OPG than the estrogen-deficient group (P < 0.05). The estrogen-sufficient group and both groups treated with strontium ranelate showed lower expression of RANKL than the estrogen-deficient group (P < 0.05). CONCLUSIONS: Strontium ranelate benefited BH and the expression of bone markers in tooth-extraction wound in estrogen-deficient rats whereas its benefits in estrogen-sufficient rats were modest.
Subject(s)
RANK Ligand , Thiophenes , Animals , Estrogens , Female , Humans , Ovariectomy , Rats , Rats, Wistar , Thiophenes/therapeutic useABSTRACT
PURPOSE: To evaluate the gene expression levels of semaphorins 3A, 3B, 4A, and 4D in both healthy and diseased implants. MATERIALS AND METHODS: Subjects with peri-implantitis presented clinical attachment loss, probing depth ≥ 5 mm, bleeding on probing and/or suppuration, and radiographic bone loss > 4 mm. Peri-implant tissue biopsy specimens were sampled for analysis of the mRNA expression levels for semaphorins 3A, 3B, 4A, and 4D. A real-time polymerase chain reaction was performed, and the gene expression levels of semaphorins in relation to the housekeeping gene were analyzed by using the nonparametric Mann-Whitney test (P < .05). RESULTS: Thirty-five subjects (16 men, 19 women; mean age: 54.12 ± 2.34 years) with implant-supported restorations, using screw-shaped dental implants with internal or external hexagon were enrolled in this study. Higher levels of semaphorins 3A and 4D were detected in the peri-implantitis compared with the healthy tissues (P = .0011 and P = .0404, respectively), whereas Sem4A levels were significantly higher in the control group (P < .0001). Differences between groups in the expression levels of Sem3B were not significant. CONCLUSION: Advanced peri-implantitis lesions showed higher levels of gene expression for Sem3A and Sem4D and lower levels of Sem4A in comparison to tissues obtained from a healthy dental implant.
Subject(s)
Antigens, CD/genetics , Gene Expression Regulation/physiology , Membrane Glycoproteins/genetics , Peri-Implantitis/genetics , Semaphorin-3A/genetics , Semaphorins/genetics , Case-Control Studies , Dental Implants , Female , Humans , Male , Middle Aged , Peri-Implantitis/surgery , RNA, Messenger/genetics , Real-Time Polymerase Chain Reaction , SuppurationABSTRACT
The lateralization of the inferior alveolar nerve (LIAN) and short implants are efficient options for rehabilitation of the posterior atrophic mandible. However, the loss of bone leads to prosthesis with greater height and lever effect that in turn can have different impact on treatments. Through the finite element method, the present study tests the hypothesis that conventional implants placed under LIAN and short implants have similar risk of bone loss regarding variable height of the crown and that crown-to-implant ratio is not a reliable resource to evaluate risk in these treatments. Computed tomography scans of mandibles were processed and implants and prosthetic components were reverse engineered for reconstruction of three-dimensional models to simulate 3 elements fixed partial dentures supported by 2 osseointegrated implants. The models of implants were based on MK III implants (Nobel Biocare, Zurich, Switzerland) with 4âmm in diameter by 7âmm in length representing short implants, and 15âmm in length representing implants used in LIAN. The implant/crown ratio for short implants was 1:1.5, 1:2, and 1:2.5 and LIAN models were modeled with exactly the same prosthesis, resulting in implant/crown ratios of 1:0.67, 1:0.89, and 1:1.12. The results partially rejected the hypothesis that LIAN and short implants have similar risk of bone loss, showing that although LIAN results were better in the models evaluated, the variations in height had proportionally similar impact on both treatments and accepted the hypothesis that crown-to-implant ratio was not a reliable resource to evaluate risk.
Subject(s)
Alveolar Bone Loss/diagnostic imaging , Dental Prosthesis Design , Dental Prosthesis, Implant-Supported , Finite Element Analysis , Imaging, Three-Dimensional , Mandibular Diseases/diagnostic imaging , Mandibular Nerve/diagnostic imaging , Prosthesis Fitting , Tomography, X-Ray Computed , Computer-Aided Design , Humans , Models, Dental , SoftwareABSTRACT
Um dos recursos recentes da engenharia tecidual para auxiliar no tratamento de defeitos ósseos é a proteína morfogenética óssea recombinante BMP-2 (rhBMP-2) que, entre outros fatores, permite melhorar a previsibilidade de volume e contorno de um procedimento de enxertia óssea. Para que seus resultados sejam satisfatórios, é necessário conhecer suas características, vantagens e limitações. O presente trabalho apresentou um caso clínico de grande demanda estética, no qual foi utilizada combinação de rhBMP-2 com osso desproteinizado e tela de titânico para garantir um contorno ósseo adequado na região da maxila anterior. As indicações, características, vantagens e desvantagens do rhBMP-2 como auxiliar em tratamentos de regeneração óssea também foram apresentadas e discutidas...
A recent resource for tissue engineering to assist in the treatment of bone defects is recombinant human bone morphogenetic protein BMP-2 (rhBMP-2), which, among other effects, improves the predictability of the volume and contour of bone grafting procedures. For a satisfactory outcome, it is important to know its characteristics, advantages and limitations. This paper presents a case of great aesthetic demand where the rhBMP-2 was used in combination with deproteinized bone and titanium mesh to ensure adequate bone contour in the anterior maxillary region. The indications, characteristics, advantages and disadvantages of rhBMP-2 as an aid in bone regeneration treatments are also presented and discussed...
Subject(s)
Humans , Female , Aged , Bone Regeneration , Bone Transplantation , Dental Implants , Maxilla , Esthetics, DentalABSTRACT
Características e hábitos dos pacientes podem comprometer tratamentos de enxertos ósseos, mesmo que a técnica e o material utilizados sejam adequados do ponto de vista biológico e celular. Paciente se apresentou com mobilidade de uma prótese total fixa implantossuportada instalada há 22 anos, suportada por implantes do tipo Garbaccio e justaósseo. O planejamento inicial incluiu remoção dos implantes e regeneração óssea com o conjunto rhBMP-2 mais hidroxiapatita, fosfato tricálcio e telas de titânio como arcabouço, porém, ocorreu comprometimento do enxerto, provavelmente devido ao trauma mecânico, químico e térmico do consumo de charuto, mesmo interrompendo o hábito até o selamento da fibromucosa. Para corrigir o problema, uma nova estratégia foi utilizada para evitar o estiramento da fibromucosa, que consiste na colocação de implantes no mesmo dia do enxerto para fornecer rigidez ao mesmo e utilização de L-PRF. Considerações sobre os materiais utilizados, as causas do insucesso inicial e a mudança do plano de tratamento são apresentadas
Dental treatment with bone grafts can be jeopardized in patients presenting certain habits and characteristics even when material and technique are acceptable from the biological standpoint. In this case report, a patient presented with mobility of his implant-supported fixed prosthesis made 22 years ago over Garbaccio and subperiosteal implants. The treatment planning included implant removal and bone regeneration using rhBMP-2, hydroxyapatite, tricalcium phosphate and titanium meshes as scaffolds; however, in the meantime, graft was compromised due to mechanical, chemical, and thermal trauma under cigar smoking, even with cessation until mucosal sealing. To overcome this problem, a new strategy was used to avoid mucosa stretching, with dental implants placed in the same day and reinforced by grafting with L-PRF. Considerations on failure and changes on treatment planning are presented
