A prospective case series on surgical treatment of circumferential and semi-circumferential defects due to peri-implantitis

Abstract Different surgical treatment strategies for peri-implantitis with the use of graft material and membranes have been suggested without any longitudinal remarkable success rate. The present preliminary study was aimed to analyze a new clinical approach based on the disinfection of the implant connection, the disinfection of the implant surface and GBR approach in the treatment of circumferential and semi-circumferential bony defect resulting from peri-implantitis. Six consecutive patients were selected for the present study. After removal of factors that could potentially influence peri-implant pathology, the prosthetic rehabilitation was always removed and a full thickness flap was elevated to allow access to the peri-implant defect and the exposed implant surface. Once the defect was degranulated and the implant surface cleaned, a mixture (50:50) of autogenous bone and allograft was used. Guided bone regeneration technique using membranes was adopted and the flaps were closed for a submerged healing. Six months thereafter, a new re-opening procedure was performed and cleaned superstructures and crowns were repositioned. Patients were followed for one year thereafter and recalled for a customized oral hygiene every three months. Radiological and periodontal analysis was performed before surgery and every six months. The studied procedure was associated with a pronounced increase in REC and CAL with stable peri-implant conditions at 6 and 12 months. PI, BOP and PD values were significantly reduced both at 6 and 12 months. At 12 months, a mean PD gain of 4.5 mm and a bone loss reduction of 5.1 mm was obtained. Within the limitation of the present preliminary study, the proposed technique might represent a promising result for treatment of circumferential and semi-circumferential bone defects around implants affected by peri-implantitis.

A perda óssea radiográfica ao redor dos implantes de largo diâmetro se compara aos implantes de diâmetro estreito/ convencional no mesmo paciente? / Does the radiographic bone loss around wide diameter compares to standard/narrow dental implants in the same patient? A literature review

Verificar a perda óssea radiográfica ao redor dos implantes de largo diâmetro quando implantes de diâmetro estreito/convencional são usados no mesmo estudo. Métodos: uma busca eletrônica feita entre os anos de 1966 e 2012 no PubMed/Medline, combinando as palavras-chave dental implants, wide diameter, wide body, large platform, large diameter e wide platform, foi realizada. Na primeira fase, 486 artigos foram recuperados para análise preliminar do título e dos resumos até 1º de março de 2012. Na segunda fase (60 artigos), estudos laboratoriais, modelos animais, estudos de casos e séries de casos com menos de um ano de acompanhamento foram excluídos. O desfecho primário foi a mensuração da perda óssea radiográfica. Resultados: sete estudos (dois prospectivos, dois RCT prospectivos, três retrospectivos) foram selecionados. Os diâmetros dos implantes variaram de 3,5 mm a 8,0 mm. Em geral, os valores de perda óssea para os implantes estreitos/convencionais e de largo diâmetro foram menores do que 2,0 mm, tanto nos estudos prospectivos (faixa um/três anos) como nos retrospectivos (faixa um/seis anos). Dois estudos retrospectivos atribuíram as diferenças observadas às curvas de aprendizagem e desenhos dos implantes. Ainda, dois estudos prospectivos demonstraram os benefícios dos protocolos plataforma switching (4,1/5,0 mm) na redução da perda óssea pelo menos um ano depois. Um RCT não demonstrou diferenças significativas (um ano de acompanhamento; implantes de 8 mm versus implantes de 4 mm de diâmetro). A maioria dos implantes foi inserida com protocolo de dois estágios e em sítios já cicatrizados. Conclusão: dentro dos limites desta revisão, a perda óssea radiográfica ao redor dos implantes de largo diâmetro não difere dos implantes estreitos/convencionais, quando comparada para a mesma população de pacientes...

To verify radiographic bone loss levels around wide-body dental implants when narrow/or standard ones are used in the same study. Methods: an electronic search between the years of 1966 to 2012 was made on the PubMed/Medline database combining the keywords “dental implants”, “diameters”, “wide diameter”, “wide body”, “large platform”, “large diameter”, and “wide platform”. In the first phase, four-hundred and eight-six articles were retrieved for preliminary title and abstract analyses until March 1st, 2012. In the second phase (60 articles), no laboratory, animal, case studies, or clinical studies with less than one-year of follow-up were included. The primary outcome was radiographic bone loss measurement. Results: seven studies (two prospective, two prospective RCTs, three retrospective) were selected. Implant diameters varied from 3.5 mm to 8.0 mm. Overall mean bone loss values for narrow/standard and wide diameters were less than 2.0 mm in both prospective (range: 1-3 years) and retrospective (range: 1-6 years) trials. Two retrospective studies attributed the observed differences due to learning curves and implant designs. Also, two prospective studies demonstrated the benefi ts of platform switching protocols (4.1/5.0 mm) in reducing bone loss at least one year later. One RCT demonstrated no significant differences (1 year of follow-up; 8 mm - versus 4 mm - diameter fi xtures). Most implants were inserted with a two-stage technique and at healed sites. Conclusions: within the limits of this review, radiographic bone loss around wide diameter implant does not differ from narrow/standard diameters in the same patient population...

Mechanical testing of thin-walled zirconia abutments

Although the use of zirconia abutments for implant-supported restorations has gained momentum with the increasing demand for esthetics, little informed design rationale has been developed to characterize their fatigue behavior under different clinical scenarios. However, to prevent the zirconia from fracturing, the use of a titanium connection in bi-component aesthetic abutments has been suggested. Objective: Mechanical testing of customized thin-walled titanium-zirconia abutments at the connection with the implant was performed in order to characterize the fatigue behavior and the failure modes for straight and angled abutments. Material and Methods: Twenty custom-made bi-component abutments were tested according to ISO 14801:2007 either at a straight or a 25° angle inclination (n=10 each group). Fatigue was conducted at 15 Hz for 5 million cycles in dry conditions at 20°C±5°C. Mean values and standard deviations were calculated for each group. All comparisons were performed by t-tests assuming unequal variances. The level of statistical significance was set at p≤0.05. Failed samples were inspected in a polarized-light and then in a scanning electron microscope. Results: Straight and angled abutments mean maximum load was 296.7 N and 1,145 N, the dynamic loading mean Fmax was 237.4 N and 240.7 N, respectively. No significant differences resulted between the straight and angled bi-component abutments in both static (p=0.253) and dynamic testing (p=0.135). A significant difference in the bending moment required for fracture was detected between the groups (p=0.01). Fractures in the angled group occurred mainly at the point of load application, whereas in the straight abutments, fractures were located coronally and close to the thinly designed areas at the cervical region. Conclusion: Angled or straight thin-walled zirconia abutments presented similar Fmax under fatigue testing despite the different bending moments required for fracture...

Evaluation of the antimicrobial effect of super-oxidized water (Sterilox®) and sodium hypochlorite against Enterococcus faecalis in a bovine root canal model

ABSTRACT Ideally root canal irrigants should have, amongst other properties, antimicrobial action associated with a lack of toxicity against periapical tissues. Sodium hypochlorite (NaOCl) is a widely used root canal irrigant, however it has been shown to have a cytotoxic effect on vital tissue and therefore it is prudent to investigate alternative irrigants. Sterilox's Aquatine Alpha Electrolyte® belongs to the group of the super-oxidized waters; it consists of a mixture of oxidizing substances, and has been suggested to be used as root canal irrigant. Super-oxidized waters have been shown to provide efficient cleaning of root canal walls, and have been proposed to be used for the disinfection of medical equipment. OBJECTIVE: To compare the antimicrobial action against Enterococcus faecalis of NaOCl, Optident Sterilox Electrolyte Solution® and Sterilox's Aquatine Alpha Electrolyte® when used as irrigating solutions in a bovine root canal model. METHODOLOGY: Root sections were prepared and inoculated with E. faecalis JH2-2. After 10 days of incubation the root canals were irrigated using one of three solutions (NaOCl, Optident Sterilox Electrolyte Solution®and Sterilox's Aquatine Alpha Electrolyte®) and subsequently sampled by grinding dentin using drills. The debris was placed in BHI broth and dilutions were plated onto fresh agar plates to quantify growth. RESULTS: Sodium hypochlorite was the only irrigant to eliminate all bacteria. When the dilutions were made, although NaOCl was still statistically superior, Sterilox's Aquatine Alpha Electrolyte® solution was superior to Optident Sterilox Electrolyte Solution®. CONCLUSIONS: Under the conditions of this study Sterilox's Aquatine Alpha Electrolyte® appeared to have significantly more antimicrobial action compared to the Optident Sterilox Electrolyte Solution® alone, however NaOCl was the only solution able to consistently eradicate E. faecalis in the model.

Análise clínica retrospectiva (4 - 6 anos) dos implantes P-I Brånemark Philosophy / Multicenter, clinical retrospective analysis (4-6 year-follow-up) of P-I Brånemark Philosophy dental implants

Este trabalho teve como objetivo avaliar retrospectivamente a taxa de sobrevivência longitudinal de um novo conceito de implantes, tendo como objetivo adicional medir o remodelamento ósseo peri-implantar após o primeiro ano de carregamento protético e ao final do acompanhamento. Entre janeiro de 2002 e janeiro de 2005, seis centros clínicos selecionaram 412 pacientes (248 homens, 164 mulheres) que receberam os implantes P-I Brånemark Philosophy. O protocolo de preparação cirúrgica foi o preconizado por Brånemark especialmente para estes implantes. Os implantes foram instalados com torque de aproximadamente 45 Ncm. Coroas unitárias (SC), próteses parciais fixas (FPDs) e próteses totais (CD) foram confeccionadas imediatamente ou entre 45-128 dias. O remodelamento ósseo foi avaliado radiograficamente em relação às faces mesiais e distais dos implantes utilizando-se um software. O período de observação foi de 48 a 72 meses. Dos 1.161 implantes examinados inicialmente, 39 falharam (3,36%). No total, 528 implantes foram instalados em mandíbula e 633 em maxila. A taxa de sobrevivência dos implantes foi de 96,64% (mandíbula = 97,2%; maxila = 96,2%). Não houve diferenças estatisticamente significativas entre as taxas de sobrevivência dos implantes com carregamento imediato ou tardio. Cento e trinta e cinco implantes foram instalados utilizando-se a técnica de reconstrução com enxertos. A remodelagem óssea cortical no primeiro ano após o carregamento e último período de acompanhamento foi de 1,63 mm e 2,18 mm, respectivamente. O estudo concluiu que o novo conceito de implantes funcionais desenvolvidos e patenteados pelo professor Per-Ingvar Brånemark fornecem resultados longitudinais de sobrevivência muito bons, compatíveis com a literatura atual, possibilitando a aplicação clínica com segurança.

To perform a long-term retrospective analysis of a new implant concept, with the aim to measure periimplant bone remodeling 1 year after loading and at the final follow-up period. Between January 2002 and January 2005, six private centers selected 412 patients (248 men, 164 women) who received P-I Brånemark Philosophy dental implants. The surgical protocol was performed according to protocols established by Brånemark, especially for these implants. All implants were inserted approximately at 45Ncm torque. Single crowns (SC), fixed partial prostheses (FPDs) and complete dentures (CD) were inserted soon after or between 45-128 days after surgery. Bone remodeling was measured at mesial and distal aspects with adequate computer software. The observation period was between 48-72 months. Of the 1,161 inserted implants, 39 were lost (3.36%). Overall, 528 implants were placed in the mandibular and 633 in the maxillary arches. The survival rate was of 96.64% (mandible = 97.2%; maxilla = 96.2%). No significant differences on SR were verified between immediate and delayed loading. One-hundred and thirty-five implants were installed along with bone grafts. Bone remodeling at first year after loading and in the last follow-up were 1.68mm and 2.18mm, respectively. This new implant concept developed and patented by Prof. Brånemark provided good long-term survival results similar to the published literature e and can be safely used into clinical practice.

Restauração dentoalveolar imediata pós-exodontia com implante platform switching e enxertia / Immediate dentoalveolar restoration postextraction with platform switching implant placement and bone grafting: a clinical case

Este artigo descreve o procedimento de restauração imediata pós-exodontia em alvéolo comprometido na região do incisivo central superior. Foi realizada a instalação de um implante associada ao enxerto de lâmina óssea da tuberosidade da maxila para a recuperação do defeito ósseo. O posicionamento adequado do implante, a inserção da lâmina óssea no defeito alveolar até o nível da plataforma do implante, a plataforma switching e o perfil de emergência da coroa provisória, promovendo um espaço para permitir a acomodação do tecido mole, foram os critérios utilizados que permitiram o sucesso deste caso clínico. Este procedimento promoveu a recuperação da estrutura anatômica dentoalveolar perdida em um único procedimento, sem retalho, com a manutenção do contorno da margem gengival e estética satisfatória.

This paper describes the procedure of immediate restoration in a compromised fresh extraction socket in the region of upper central incisors. An implant was inserted, together with a bone sliver graft from the maxillary tuberosity, in order to restore the bone defect. The criteria that enabled success in this clinical case were the adequacy of implant positioning; the insertion of a bone sliver into the socket defect, to the level of the implant platform; the platform switching; and the emergence profile of the provisional crown, which promoted space for the soft tissue to be accommodated. This procedure promoted recovery of the lost dentoalveolar anatomical structure in a single procedure, without a flap, while maintaining the gingival profile and satisfactory esthetics.