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1.
Hua Xi Kou Qiang Yi Xue Za Zhi ; 38(1): 30-36, 2020 Feb 01.
Artigo em Chinês | MEDLINE | ID: mdl-32037763

RESUMO

OBJECTIVE: This study aims to investigate the occlusal and myoelectric characteristics of implant-supported fixed denture in the mandibular region and provide reference for the design of fixed restoration. METHODS: Sixty edentulous patients with implant-supported fixed denture were selected and divided into three groups: group A, 20 cases with implant-supported fixed restoration in the maxillary region; group B, 20 cases with natural dentition, and group C, 20 cases with removable partial denture. The T-scan 8.0 digital occlusion analysis system was used to evaluate the occlusal characteristics of patients in the three groups at intercuspal, protrusion, and left and right lateral positions. Electromyography was used to analyze the myoelectric amplitude and bilateral asymmetry index of the anterior temporalis and masseter of the three groups in different states such as resting and clenching. The relationship between occlusion and myoelectricity was also investigated. RESULTS: In the occlusion analysis by T-scan, the occlusion time, the balance of left and right bite force, the left and right asymmetry of the occlusion center, the trajectory of central occlusion force, and the disclusion time were higher in group C than in groups A and B (P<0.05). No significant differences were observed in the anterior and posterior asymmetry of the occlusion center and percentage of bite force at anterior region among the three groups. In the analysis of myoelectricity, the myoelectric amplitude at resting state and the asymmetry index of masticatory muscles in group C were higher than those in groups A and B (P<0.05). The myoelectric amplitude during clenching in groups A and B groups was higher than that in group C (P<0.05). CONCLUSIONS: In implant-supported fixed restoration at edentulous mandibular, when maxillary includes the removable partial denture, degree of occlusal instability and left and right asymmetry of occlusion center are greater than those with the natural dentition and implant-supported fixed denture at maxillary. The myoelectricity is closely related to occlusion. The removable partial denture can increase the myoelectric activity and reduce the potential of the masticatory muscle. The asymmetry of bilateral myoelectricity is related to the occlusion imbalance.


Assuntos
Implantes Dentários , Prótese Dentária Fixada por Implante , Força de Mordida , Humanos , Mandíbula , Músculos da Mastigação
2.
Hua Xi Kou Qiang Yi Xue Za Zhi ; 38(1): 86-89, 2020 Feb 01.
Artigo em Chinês | MEDLINE | ID: mdl-32037772

RESUMO

Vertical bone insufficiency in the maxillary posterior teeth is a common clinical situation. At present, the bone insufficiency in the maxillary posterior teeth is mainly overcome by bone grafting through maxillary sinus floor elevation. Compared with traditional axial implantation, tilted implantation can better avoid bone grafting, reduce complications, shorten the treatment cycle, reduce the treatment cost for patients, and gradually be promoted in clinical settings. This article reviews the concept, biomechanics, clinical evaluation, and digital trend of tilted implants of maxillary posterior teeth.


Assuntos
Implantes Dentários , Levantamento do Assoalho do Seio Maxilar , Implantação Dentária Endo-Óssea , Planejamento de Prótese Dentária , Humanos , Maxila , Seio Maxilar
3.
Hua Xi Kou Qiang Yi Xue Za Zhi ; 38(1): 95-100, 2020 Feb 01.
Artigo em Chinês | MEDLINE | ID: mdl-32037774

RESUMO

Dental implants have become the main choice for patients to fill in their missing teeth. A precise placement is the basis for a functional and aesthetic restoration. A digital surgical guide is a carrier that transfers the preoperative plan of dental implants to the actual surgery. This paper provides some references that can help clinicians improve the accuracy of implant surgery by stating the development, classification, advantages and disadvantages, and factors that affect the accuracy of digital guides.


Assuntos
Implantes Dentários , Cirurgia Assistida por Computador , Projeto Auxiliado por Computador , Implantação Dentária Endo-Óssea , Estética Dentária , Humanos , Imagem Tridimensional , Planejamento de Assistência ao Paciente
4.
Hua Xi Kou Qiang Yi Xue Za Zhi ; 38(1): 108-113, 2020 Feb 01.
Artigo em Chinês | MEDLINE | ID: mdl-32037777

RESUMO

Identifying the ideal implantation site is important for the long-term stability and effectiveness of follow-up restorations. Implant surgical guide and navigation are used to determine the implantation site in clinic and improve the precision of implantation. However, due to difficulties in digital methods, such as multiple procedures, high cost, and actual accuracy of more than 1 mm, many physicians still prefer to operate with free hand. In preoperative, intraoperative, and postoperative procedures, time-saving and practical methods for implant site evaluation are lacking. In many cases, oral physicians found that the position deviates only by cone beam CT, which was costly to modify the position. In this article, we presented a precise implantation insertion technology that is guided by a measurable technique throughout the implantation application for all implant systems. This method was guided by a dynamic control measuring ruler, which functions together with the measuring and intraoperative locating rulers. The 3D space of the operative area was measured by a measuring ruler prior to operation, and the implant plan and quantitative guidance design were conducted according to the measured and cone beam CT data. The whole implantation process was guided by the dynamic control measuring ruler, and measuring verification results were also considered. This method can realize the quantification of the entire preoperative space analysis, intraoperative precise implantation guidance, and postoperative site measurement and evaluation. This practical technique also helps to adjust the position, improve the implantation accuracy and is suitable in generalizing dental implantation.


Assuntos
Implantes Dentários , Cirurgia Assistida por Computador , Projeto Auxiliado por Computador , Tomografia Computadorizada de Feixe Cônico , Implantação Dentária Endo-Óssea , Imagem Tridimensional , Planejamento de Assistência ao Paciente
5.
Quintessence Int ; 51(3): 212-218, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32020131

RESUMO

OBJECTIVE: The aim was to investigate the presence of Entamoeba gingivalis and Trichomonas tenax in peri-implantitis lesions. METHOD AND MATERIALS: A total of 141 individuals were included in this study, of which 40 had clinically healthy implants (group H); the remaining were associated with peri-implantitis (group P). Gingival crevicular fluid was collected using absorbent paper, followed by a dental plaque sample from the peri-implant sulcus/pocket using a titanium curette. The samples were transferred into an Eppendorf tube. Each specimen was divided into two parts. One part was examined under a light microscope at a 10 × and 40 × magnification to detect parasites. The other part was spread on a microscope slide, stained with Giemsa stain, and examined under a microscope at 100 × magnification. Pearson chi-square test was used in the statistical analysis of data, with a significance level of P < .05. RESULTS: Although there was no presence of parasite around the healthy implants, two parasites were detected in peri-implantitis lesions. Out of 101 lesions, 31 (30.7%) showed E gingivalis, and 34 (33.6%) presented with T tenax. There was a statistically significant difference between the presence of E gingivalis and demographic data including gender, education status, frequency of dental visits, and brushing frequency. Presence of T tenax in lesions was correlated with frequency of dental visits (P < .05). It was observed that E gingivalis and T tenax were mostly detected in the mandible (P = .004 and .014, respectively) in comparison with the maxilla. CONCLUSION: This study showed that peri-implantitis lesions were involved with E gingivalis and T tenax, in contrast to the healthy areas.


Assuntos
Implantes Dentários , Entamoeba , Peri-Implantite , Trichomonas , Líquido do Sulco Gengival , Humanos
6.
Artigo em Inglês | MEDLINE | ID: mdl-32032399

RESUMO

Growth factors have been used in numerous oral applications to aid in bone formation after tooth extraction. Bone morphogenetic proteins (BMPs) are members of the transforming growth factor-b superfamily and are involved in the differentiation of pluripotent mesenchymal cells, leading to new bone formation through osteoblastic induction. This study examined histologic wound healing following extraction and ridge preservation using recombinant human BMP-2 (rhBMP-2) and a collagen sponge. Formation of new vital bone was seen, suggesting that this material is a viable option for ridge preservation in preparation for implant placement.


Assuntos
Aumento do Rebordo Alveolar , Implantes Dentários , Processo Alveolar , Proteína Morfogenética Óssea 2 , Proteínas Morfogenéticas Ósseas , Estética Dentária , Humanos , Osteogênese , Proteínas Recombinantes , Fator de Crescimento Transformador beta
7.
Compend Contin Educ Dent ; 41(2): 112-117, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32017588

RESUMO

The purpose of impression-taking is to attain the accurate transfer of intraoral information for extraoral use. It is a crucial step in performing a successful dental implant restorative procedure. To accurately replicate the implant position for adaptation of an abutment that will completely engage with the implant, a pick-up impression is taken with an impression coping. Several factors can affect seating of the impression coping, including soft-tissue interference, the size of the impression coping, angulation, proximity or contact with adjacent teeth, damage to the coping, misfit caused by use of other manufacturers' parts, and differences between seating in an external- versus internal-connection implant. This article presents use of a novel verification guide that is intended to ensure complete seating of the impression coping with the implant.


Assuntos
Implantes Dentários , Técnica de Moldagem Odontológica , Adaptação Psicológica , Materiais para Moldagem Odontológica , Modelos Dentários
8.
Compend Contin Educ Dent ; 41(2): 102-110, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32017589

RESUMO

The decision to prescribe an adjunctive antibiotic when placing a dental implant in a systemically healthy patient who is not receiving a bone graft remains a controversial issue. In an effort to elucidate this enigma, the authors analyzed, from a statistical and clinical significance perspective, seven current systematic reviews that address this concern. Hypothesis testing often does not provide clear understanding regarding the efficacy of the administration of antibiotics in association with clinical implantations. Therefore, number needed to treat (NNT) calculations may be used to determine the effectiveness of antibiotics to reduce dental implant losses. The NNT indicates how many additional patients need to be treated with antibiotics to avoid an additional implant failure in another patient. This article addresses two questions: Do antibiotics help reduce implant loss, and if they do, what is the best drug dosage to use when placing dental implants? Based on NNT calculations, the data is interpreted to denote that adjunctive antibiotics help reduce early implant loss in systemically healthy patients who are not receiving bone grafts and that 2 gm of amoxicillin prior to implant placement in non-allergic patients appears to be a satisfactory drug dose that provides a clinically significant benefit.


Assuntos
Antibacterianos , Implantes Dentários , Amoxicilina , Antibioticoprofilaxia , Implantação Dentária Endo-Óssea , Falha de Restauração Dentária , Humanos
9.
Quintessence Int ; 51(3): 230-237, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32020133

RESUMO

OBJECTIVES: Severe atrophied edentulous posterior mandible with inadequate bone height superior to the inferior alveolar canal may require transposition of the inferior alveolar nerve in order to insert dental implants. Mandibular fractures are considered a rare complication of this procedure. Implant-related spontaneous fractures of the mandible represent 0.2% of patients with inserted implants in an edentulous mandible. This report presents two cases of mandibular fractures that occurred 3 to 4 weeks after inferior alveolar nerve transposition, and were managed successfully by conservative nonsurgical treatments. METHOD AND MATERIALS: Overall, 132 procedures of inferior alveolar nerve transposition in 98 patients were performed over a period of 10 years with 379 dental implants inserted in one stage with the procedure. Patients were examined every 2 weeks. The inferior alveolar nerve function was evaluated with various sensory tests. Panoramic radiographs were obtained immediately, at 3 months, and at 1 year after the surgery. The patients received implant-supported fixed prostheses after 3 to 5 months. RESULTS: The healing process was uneventful in 96 patients; however, in two patients (1.5%) spontaneous fracture of the treated site was observed 3 and 4 weeks postoperatively. The fractures lines occurred at a failed implant site. Both cases were treated conservatively. CONCLUSIONS: Spontaneous fractures following inferior alveolar nerve transposition are an important but rare complication. Conservative treatment modalities might be useful and indicated in some of those cases.


Assuntos
Perda do Osso Alveolar , Implantes Dentários , Fraturas Espontâneas , Fraturas Mandibulares , Tratamento Conservador , Implantação Dentária Endo-Óssea , Prótese Dentária Fixada por Implante , Humanos , Mandíbula , Nervo Mandibular
10.
Compend Contin Educ Dent ; 41(1): 26-30; quiz 31, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31895579

RESUMO

Dental implants arguably have become the preferred treatment modality for replacing missing teeth. The success of implants, however, depends on the precision of the implant placement to effectively support prosthetic restorations. With the evolution of static surgical guides, implant dentistry science has taken enormous strides toward ensuring accurate placement of dental implant fixtures, yet emerging digital protocols show the potential for dynamic real-time clinical support to the operator. Robotic-assisted dental surgery (RADS) is a novel form of dynamic surgical guidance that, in addition to visual navigation, offers haptic guidance for implant treatment planning, osteotomy preparation, and implant placement. This article discusses RADS and includes a case study that, to the authors' knowledge, is the first report of a robotic-assisted dental procedure with quantitative accuracy analysis for prosthetically driven planning and immediate placement of a single-tooth replacement.


Assuntos
Implantes Dentários , Procedimentos Cirúrgicos Robóticos , Cirurgia Assistida por Computador , Implantação Dentária Endo-Óssea , Planejamento de Assistência ao Paciente
11.
Compend Contin Educ Dent ; 41(1): 34-41, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31895581

RESUMO

Dental implants are often a preferred option when replacing missing teeth. In the esthetic zone, however, a proper soft-tissue framework is essential to accommodate the final restorations. A wax-up and subsequent esthetic provisional prototype are key components for planning prior to implant placement and performing any grafting procedures that may be needed. This case report describes a combination treatment approach that incorporates orthodontics, implant placement, and restorative dentistry to achieve the maximum esthetic potential the patient desired. The article outlines proper diagnosis, treatment planning, and sequencing.


Assuntos
Implantes Dentários para Um Único Dente , Implantes Dentários , Implantação Dentária Endo-Óssea , Prótese Dentária Fixada por Implante , Estética Dentária , Humanos , Sorriso
13.
J Prosthet Dent ; 123(2): 290.e1-290.e8, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31902534

RESUMO

STATEMENT OF PROBLEM: The adhesion properties of modified cement-retained implant prostheses have not been elucidated. PURPOSE: The purpose of this in vitro study was to compare the adhesion strength and the flow conditions of the adhesives of 3 common modified cement-retained methods (MCRMs). MATERIAL AND METHODS: Four cement-retained methods were used: an occlusal hole for screw access (OH), a lingual hole for releasing the excess adhesive (LH), a resin replica for the titanium abutment (RR), and a control group (no holes and no resin trial abutments). Eight zirconia prostheses in each group were processed and cemented. The adhesion strength was examined by mechanical tensile experiments (MTE) in vitro. One-way ANOVA and the LSD post hoc tests were used to compare the results of the MTE (α=.05). The flow conditions of adhesives in the adhesion process were analyzed by computational fluid dynamics (CFD). CFD-Post 16.0 (ANSYS, Inc) was used to analyze the results of the CFD analyses. RESULTS: The adhesion strength of each group was 289.3 ±37.7 N in the LH group, 281.3 ±50.1 N in the OH group, 263.3 ±49.3 N in the RR group, and 239.2 ±29.4 N in the control group. A statistically significant difference is seen in the adhesion strength between the LH group and the control group (P=.025). The internal filling ratio of adhesives between the groups ranges from high to low in the order the LH group, the OH group, the RR group, and the control group. The amount of cervical overflow of adhesives between the groups ranges from less to more in the order the RR group, the OH group, the LH group, and the control group. CONCLUSIONS: MCRMs can effectively reduce the amount of cervical overflow of adhesives and improve the filling condition of the adhesive and its clearance to ensure the adhesion strength of the prostheses.


Assuntos
Dente Suporte , Implantes Dentários , Cimentos Dentários , Prótese Dentária Fixada por Implante , Análise do Estresse Dentário , Hidrodinâmica , Teste de Materiais , Resistência à Tração
14.
J Prosthodont ; 29(2): 179-184, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31889369

RESUMO

Zygomatic implants have become a predictable treatment modality for the rehabilitation of the severely atrophic maxilla. Due to differing anatomic variations, proximity to vital anatomic structures and limited intraoperative visibility, the placement of zygomatic implants can be a difficult task; compromised implant positioning may ultimately lead to postoperative surgical and prosthetic complications. The purpose of this report is to demonstrate a technique that allows for the transfer of the sinus slot position. Ultimately, this optimizes zygomatic implant axis trajectory from preoperative prosthetic planning by using cone beam computed tomography (CBCT) and 3-dimensional (3D) planning software to fabricate a stereolithographic 3D-printed surgical guide.


Assuntos
Implantes Dentários , Zigoma , Tomografia Computadorizada de Feixe Cônico , Implantação Dentária Endo-Óssea , Maxila , Impressão Tridimensional
15.
J Prosthodont ; 29(2): 101-106, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31916642

RESUMO

PURPOSE: To retrospectively evaluate the treatment outcome of immediate implants placed in fresh extraction sockets without bone augmentation after 22 years of function. MATERIALS AND METHODS: The study group received implant therapy in 1997, including surgical placement and prosthodontic rehabilitation. The mean age of the subjects at the time of implant placement was 40 ± 5.54 years. A total of 35 subjects received 36 implants in fresh extraction sockets without bone augmentation. Definitive prostheses were placed 4 to 6 months after implant placement. Implant treatment outcomes were evaluated using clinical and radiographic parameters obtained during follow-up visits at 1, 5, 10, 15, 20, and 22 years after prosthetic loading. RESULTS: Among the 35 treated subjects, five patients moved out of the country and could not be evaluated at the follow-up times. A total of 29 subjects were included in the study with a drop-out rate of 14.1%. Of these, one patient lost the implant during the osseointegration period before prosthodontic treatment. No other implant failure or complication during the rest of the follow-up period was reported, thus giving a cumulative survival rate of 97.2% during the 22-year follow-up. The change in marginal bone level was less than 2 mm in most subjects at the 22-year examination. The mean bone loss from baseline to 22-year follow-up was 1.61 mm, and the mean bone level at the 22-year follow-up examination was situated at 2.13 ± 0.023 mm from the implant platform, which was used as the reference point. CONCLUSIONS: Immediate implant placement in extraction sockets exhibits excellent prognosis even when bone augmentation is not performed.


Assuntos
Perda do Osso Alveolar , Implantes Dentários , Carga Imediata em Implante Dentário , Adulto , Implantação Dentária Endo-Óssea , Seguimentos , Humanos , Pessoa de Meia-Idade , Estudos Retrospectivos , Extração Dentária , Alvéolo Dental , Resultado do Tratamento
16.
Quintessence Int ; 51(2): 118-126, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31942573

RESUMO

OBJECTIVE: Marginal bone loss (MBL), a prognostic parameter for implant success, is associated with implant- and patient-related variables. The purpose of this study was to analyze the effects of the crown-to-implant ratio and independent factors of implant diameter, implant length, implant type, location, and platform switching on distal and mesial MBLs at the 6-, 12-, 24-, and 36-month recall sessions of single crown implant-supported restorations. METHOD AND MATERIALS: Radiographic and clinical data of patients treated with single crown implants were collected. MBL was measured at the baseline and recall sessions on panoramic radiographs. The crown-to-implant ratio was calculated by dividing the length of the crown by that of the dental implant. RESULTS: The crown-to-implant ratio had a moderately positive correlation with distal MBL at the 6-month recall session (P < .05, r = 0.469) and a weakly positive correlation at the 12- (P < .05, r = 0.220), 24- (P < .05, r = 0.214), and 36- (P < .05, r = 0.250) month recall sessions. Distal and mesial MBL did not significantly differ among the four implant types at any recall session (P > .05). The crown-to-implant ratio had no significant correlation with mesial MBL at the 12-, 24-, or 36-month recall session (P > .05), and a moderately positive correlation at the 6-month recall session (P < .001, r = 0.434). CONCLUSIONS: MBL was similar among different implant types in the short and medium terms. There was a positive correlation between distal MBL and the crown-to-implant ratio.


Assuntos
Perda do Osso Alveolar , Implantes Dentários , Coroas , Planejamento de Prótese Dentária , Prótese Dentária Fixada por Implante , Seguimentos , Humanos , Estudos Retrospectivos
17.
Quintessence Int ; 51(2): 128-141, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31942574

RESUMO

OBJECTIVES: The aim of this study was to determine the influence of patient-related systemic factors, local bone and intraoral factors, and implant-related factors on peri-implant marginal bone loss (MBL). METHOD AND MATERIALS: The following data were collected from patients who received dental implants and were recalled for examinations at least 3 years after treatment completion: medical history, age, sex, habits, periodontal health, implant size and surface, surgical procedure, prosthesis type, implant failure, Plaque Index, and oral hygiene. MBL was investigated using both baseline and follow-up panoramic radiographs. RESULTS: The study included 1,126 dental implants placed in 304 patients (185 [60.9%] women and 119 [39.1%] men). The mean age was 54.30 ± 13.52 years (range 22 to 83 years). The mean follow-up period was 58.8 ± 11.2 months. The MBL was observed in 271 (24.1%) implants, of which 160 (14.2%) were ≤ 2 mm and 111 (9.9%) were > 2 mm. Respective mean MBL values on mesial and distal sides were 0.42 ± 1.03 mm and 0.42 ± 1.02 mm. Of the implants, 19 (1.7%) were lost, leading to an implant success rate of 98.3%. Age, history of hysterectomy, history of periodontitis, oral hygiene, abrasions, smoking, implant location, implant surface, implant length, surgical procedure type, and prosthesis type were all found to be statistically significant for MBL (P < .05). Certain combinations of these factors resulted in increased MBL. CONCLUSION: In the present study, local factors had more significant effects on MBL than did systemic factors, and combinations of these factors had greater effects on MBL.


Assuntos
Perda do Osso Alveolar , Doenças Ósseas Metabólicas , Implantes Dentários , Adulto , Idoso , Idoso de 80 Anos ou mais , Planejamento de Prótese Dentária , Prótese Dentária Fixada por Implante , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Radiografia Panorâmica , Estudos Retrospectivos , Adulto Jovem
18.
Quintessence Int ; 51(2): 170-177, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31942577

RESUMO

OBJECTIVE: Some patients with Down syndrome experience premature edentulism, which can lead to severe alveolar atrophy. This may cause retention problems with purely mucosa-supported dentures and ill-fitting total dentures. The intellectual disability associated with Down syndrome, with an (implied) inadequate ability for compliance, may pose a further challenge to dental treatment. The aim of this case report was to demonstrate that a combined implant-prosthetic denture with bar constructions can, nevertheless, be implemented in elderly Down syndrome patients with limited cooperation ability. METHOD AND MATERIALS: This report is the first to describe the procedure for an implant-supported total prosthetic restoration with bar joint in a 52-year-old edentulous patient with Down syndrome and limited ability to cooperate. Previous dental solutions had severely curtailed the patient's quality of life. By combining various forms of treatment, including behavior management, the course of therapy could be adapted to the patient's cooperation capability. RESULTS: The implant-supported total prosthetic restoration with bar joint was well accepted by the patient. Moreover, the patient's relatives reported that his life quality had improved distinctly (eg, considerable weight-gain, more positive mood). No impairments of the prostheses were observed during the 24-month follow-up period, and both implants remained clinically inconspicuous. CONCLUSION: The lack, or inadequacy, of dental prostheses can impair the life quality of individuals in need of such restorations. Implant-supported dentures in combination with a bar construction improve the retention of prostheses in atrophied jaws. This form of restoration is also proving to be a successful therapy option for elderly persons with Down syndrome.


Assuntos
Implantes Dentários , Síndrome de Down , Arcada Edêntula , Idoso , Prótese Dentária Fixada por Implante , Falha de Restauração Dentária , Revestimento de Dentadura , Seguimentos , Humanos , Pessoa de Meia-Idade , Qualidade de Vida , Resultado do Tratamento
19.
Int J Oral Maxillofac Implants ; 35(1): 25-38, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31923287

RESUMO

PURPOSE: To examine the effect of controlled progressive orthodontic loading on bone around implants subjected to overloading forces. MATERIALS AND METHODS: Bilateral edentulous alveolar ridges were created in the posterior maxilla of five beagle dogs and left to heal for an 8-week period, after which 40 implants were placed. In the overloading group (OL), 16 implants were inserted and left to osseointegrate for 16 weeks; impressions were made, and metal crowns were mounted on with supraocclusal contacts with the antagonist teeth. Implants were exposed to dynamic overloading for 16 weeks. In the progressive loading + overloading group (PL+OL), 16 implants were left to osseointegrate for 8 weeks, and custom abutment cores were fabricated and coupled by pairs with Ni-Ti orthodontic springs. Ascending static forces of 100g, 200g, and 300g were each applied for a 3-week period, for a total 9-week progressive loading period. Thereafter, metal crowns with supraocclusal contacts were adapted, and a 16-week overloading protocol for implants was followed as for the overloading group. In the unloaded control group (UL), eight implants were inserted and left uncovered and unloaded for 32 weeks, that is, until the end of the experimental period, at which point all 40 implants were removed with the surrounding bone. Histologic, histomorphometric, and statistical analysis followed. RESULTS: Higher bone-to-implant contact percentage was reported for the OL group (P = .006) and PL+OL group (P < .001) compared with the UL group. Between the OL and PL+OL groups, the addition of progressive loading did not increase the bone-to-implant contact percentage (P = .225). Bone density 1 mm and 2 mm distant to the threads did not differ significantly between the three groups. Significantly lower crestal bone resorption was detected around OL group implants (P = .006) and PL+OL group implants (P = .004) compared with the UL group implants. The implant success rate was 87.5% for the UL group, 67.5% for the OL group, and 87.5% for the PL+OL group. CONCLUSION: The application of controlled progressive orthodontic loading on osseointegrated implants preceding overloading forces did not increase bone-to-implant contact. When applied, overloading significantly increased bone-to-implant contact compared with the unloaded implants. A significantly higher implant success rate was reported in the PL+OL group compared with the OL group.


Assuntos
Perda do Osso Alveolar , Implantes Dentários , Animais , Implantação Dentária Endo-Óssea , Cães , Implantes Experimentais , Mandíbula , Maxila , Osseointegração
20.
Int J Oral Maxillofac Implants ; 35(1): 39-51, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31923288

RESUMO

PURPOSE: This study evaluated a novel injectable, self-setting, osteoconductive, resorbable adhesive that provides immediate implant stabilization. MATERIALS AND METHODS: Twenty-six large canines had the mandibular second through fourth premolars and the first molar removed bilaterally. After 3 months, oversized osteotomies were prepared with only the apical 2 mm of the implant engaging native bone. One site had a novel resorbable, self-setting, mineral-organic adhesive (TN-SM) placed around the implant, a second site received bone graft, and a third site received only blood clot. Removal torque, standardized radiography, and histology were used to evaluate implant stability and tissue contact after 24 hours, 10 days, and 4 months. RESULTS: Mean removal torque values after 24 hours were 1.4, 1.3, and 22.2 Ncm for the control, bone graft, and mineral-organic adhesive, respectively. After 10 days, these values were 5.7, 6.2, and 45.7 Ncm and at 4 months increased to 88.7, 77.8, and 104.7 Ncm, respectively. Clinical, radiographic, and histologic evaluations showed a lack of inflammatory reaction. Control defects were initially radiolucent in the coronal area; grafted sites revealed particles in the gap, with both conditions gradually filling with bone over time. At 10 days, histologic evaluation demonstrated excellent biocompatibility and intimate contact of mineral-organic adhesive to both the implant and bone, providing an osseointegration-like bond; control sites revealed no bone contact in the defect area, while the bone-grafted sites revealed unattached graft particles. At 4 months, much of the mineral-organic adhesive was replaced with bone; the control and grafted sites had some bone fill, and many of the defects demonstrated no bone-to-implant contact and were filled with soft tissue or isolated graft particles. CONCLUSION: The mineral-organic adhesive provides immediate (osseointegration-like) and continued implant stabilization over 4 months in sites lacking primary stability. Experimental sites demonstrated maintenance of crestal bone levels adjacent to the mineral-organic adhesive and soft tissue exclusion without the use of membranes in this canine model. These results demonstrate that this novel mineral-organic adhesive can enable implant osseointegration in a site where insufficient native bone exists to allow immediate implant placement.


Assuntos
Implantes Dentários , Cimentos Dentários , Implantação Dentária Endo-Óssea , Mandíbula , Minerais , Osseointegração
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