Stable cranial parameters to evaluate the occlusal plane orientation in the frontal plane: a systematic review.

INTRODUCTION: A systematic review of the literature available up to October 2020 has been conducted to determine which cranial plane could represent a stable and reliable parameter to evaluate the orientation of the occlusal plane in a frontal view. EVIDENCE ACQUISITION: An electronic research was performed across the following electronic databases: PUBMED, EBSCO, SCOPUS, WoS, COCHRANE LIBRARY, SciELO, EMBASE and GOOGLE SCHOLAR. Observational studies based on imaging and anthropometry were identified, and all languages have been included. The articles were selected and analyzed by three authors independently. PICO format was adopted to analyze the studies and AXIS guidelines were used to assess the quality of evidence. EVIDENCE SYNTHESIS: We found eleven articles eligible for full-text analysis. All studies included only young subjects and analyzed the occlusal plane in relation to the frontal plane traced between the right and left tragus (Camper's and Frankfurt planes), to the interpupillary plane, and to other soft and hard tissues references. The outcomes of selected studies were various, with a low quality of evidence, and they did not allow to infer a stable cranial relation between the occlusal plane and other bone structures. CONCLUSIONS: The evidence does not support that the interpupillary plane represent a reliable parameter to evaluate the occlusal plane orientation in a frontal view; instead, the Frankfurt plane could be a much more stable reference parameter, from a morphological perspective. It is necessary to perform an observational study upon craniums to define which are the most stable cranial reference planes to determine the orientation of the occlusal plane in dentate subjects.

Eagle and Ernest Syndromes. A scoping review.

INTRODUCTION: Ossification disorders can affect the stylohyoid ligament as well the stylomandibular ligament. The symptomathology between those syndromes and other pathologies it has been a problem because there is not a guideliness. EVIDENCE ACQUISITION: With the aim to establish prevalence, diagnosis and etiopathogenesis of Eagle and Ernest syndromes, a scoping review was performed base on PRISMA criteria. EVIDENCE SYNTHESIS: 93 articles were selected to review stylohyoid ligament and Eagle syndrome. 3 articles regarding the stylomandibular ligament and Ernest syndrome were founded and selected. CONCLUSIONS: Both syndromes should be clinically diagnosed and corroborate with imaging (2D or 3D), although imaging in Ernest syndrome is not clear as well in Eagle syndrome. A decisional algorithm for diagnosis of Eagle Syndrome and Ernest Syndrome is presented.

Flapless Cone Beam Computed Tomography-Guided Implant Surgery with Contextual Transcrestal Sinus Lift Augmentation Using New Bone Compactor Tools.

In the present paper, the authors present a case report of premolar edentulism in the upper jaw treated through a guided flapless oral implant surgery with contextual crestal sinus lift, performed with a system of manual screw-tapered bone expanders (B&B Dental, San Benedetto, BO, Italy). The surgery was planned by means of dedicated software, through which the data obtained from the CBCT and from intraoral scanner impression were matched, with consequent production of a surgical template. The proposed surgical procedure is minimally invasive, very simple, and fast and ensures good comfort for the patient by avoiding the elevation of mucoperiosteal flaps and uncomfortable malleting maneuvers. In addition, the presented method shows a good degree of correspondence between the ideal position of the implant in the planning phase and the actual one detectable after the surgery.

A New Bioactive Glass/Collagen Hybrid Composite for Applications in Dentistry.

Bioactive glasses (BGs) are currently employed in a wide range of medical and dentistry applications by virtue of their bone-bonding ability. The incorporation of BGs into a collagen matrix may be used to combine the regenerative potential of these materials with the specific biological advantages of collagen. However, most of the collagen/BG composites reported in the literature are scaffolds and there is a lack of moldable putties or injectable systems. Here, granules of an innovative BG containing strontium and magnesium were mixed with collagen and PEG to obtain a putty (BGMS/C) suitable for dental applications. For the sake of comparison, granules of 45S5 Bioglass®, the gold standard among BGs, were used to prepare a 45S5/collagen putty. Both the composites were evaluated in vitro with respect to murine fibroblasts. The materials showed an excellent biocompatibility, making them interesting for possible applications in dentistry and reconstructive surgery. Moreover, BGMS/C seems to stimulate cell proliferation.

Long-term survival analysis of standard-length and short implants with multifunctional abutments.

BACKGROUND: Spherical shape and connecting bypass screw of the OT Equator abutment (Rhein83, Italy) provides several retentive possibilities, even in non-parallel implants. OBJECTIVE: This study assessed the long-term survival of standard-length and short implants receiving this multifunctional abutment. METHODS: Partially, edentulous patients (44 males and 64 females) (mean age 58.2 ± 10.5 years) rehabilitated with a fixed implant-supported prosthesis where the OT Equator abutments (Rhein83) were applied. Follow-up evaluations were performed up to 5 years following prosthesis delivery. Kaplan-Meier survival analysis and Cox regression analysis were used to determine whether the distribution of time to failure differed based on implant characteristics (length and region), adjusting for sex (α = 0.05). RESULTS: In total, 216 implants (5 × 8 mm, n = 126; 5 × 6 mm, n = 90) (Betwice, Mech & Human, Italy) were installed. The average follow-up period was 25.3 months (±19.3 months). Eight failures occurred, with most observed before loading (n = 6). Cumulative survival rates (CSR) at implant and abutment levels were 94.3% and 97.1%, respectively. Regarding implant length, CSRs were 97.8% and 90.6% for short and standard-length implants, respectively, with no difference between subgroups (logrank: χ2  = 1.34, df = 1, P = 0.25). No significant difference was also found between implants of maxilla (CSR = 92.2%) and mandible (CSR = 95.5%; logrank: χ2  = 0.08, df = 1, P = 0.78). CONCLUSION: The OT Equator abutment (Rhein83) showed a stable clinical performance, with continuous and predictable survival.

Surface treatments to improve the repair of acrylic and bis-acryl provisional materials.

PURPOSE: To evaluate the in vitro effects of the Composite Primer and different surface treatments on the shear bond strength (SBS) of acrylic and bis-acryl repairs with resin composite (RC). METHODS: Acrylic (Alike) and bis-acryl (Protemp 4) blocks were prepared. Surface roughness was standardized (0.16 µm) and grit blasting was applied to half of the samples. Blocks were divided randomly into groups according to surface treatment [methyl methacrylate monomer (MMA) for 180 seconds or bonding agents (Composite Primer and Scotchbond Multi Purpose), applied alone or following MMA]. Two consistencies of RC [ regular (Filtek Z350XT and Solare composite) or flowable (Filtek Z350XT flowable and G-aenial flowable composite) ] were used to test bond repair. Cylinders (2 mm diameter) of each RC (n= 10/group) were attached to the block surface, and SBS was measured using a universal testing machine at 0.5 mm/minute. Failure (adhesive, cohesive or mixed) was assessed under ×3.5 magnification. SBS data were analyzed using factorial ANOVA, followed by Tukey post-hoc, and Weibull moduli estimation (α = 0.05). RESULTS: The highest SBS, Weibull modulus (m) and scale parameter (σ0) were found in combined use of MMA and bonding agents (P< 0.001), regardless of the substrate, RC consistency or brand. The use of the Composite Primer and flowable RC also increased SBS (P< 0.001). Significant interaction between surface treatment and RC consistency was observed for the PMMA substrate (P< 0.001). Sandblasting did not influence SBS (P> 0.05). Adhesive failure was most prevalent (93.5%) and SBS values were significantly higher in mixed fractures (19.2± 3.8 MPa) compared to the adhesive ones (9.7± 6.0 MPa) (P< 0.001). No cohesive fracture was observed. CLINICAL SIGNIFICANCE: Composite Primer improved the adhesion of acrylic and bis-acryl repairs, especially when a flowable composite was used. When such product is not available, the combined use of MMA and a bonding agent is necessary, increasing the number of clinical steps, cost, and time required.

Long-term Short Implants Performance: Systematic Review and Meta-Analysis of the Essential Assessment Parameters.

Lack of standard criteria in the outcome assessment makes it difficult to draw conclusions on the clinical performance of short implants and, under these circumstances, determine the reasons for implant failure. This study evaluated, through a systematic review of the literature and meta-analysis, the essential parameters required to assess the long-term clinical performance of short and extra-short implants. Electronic databases (Pubmed-MEDLINE, Cochrane Library Database, Embase, and Lilacs) were searched by two independent reviewers, without language limitation, to identify eligible papers. References from the selected articles were also reviewed. The review included clinical trials involving short dental implants placed in humans, published between January 2000 and March 2014, which described the parameters applied for outcome's measurements and provided data on survival rates. Thirteen methodologically acceptable studies were selected and 24 parameters were identified. The most frequent parameters assessed were the marginal bone loss and the cumulative implant survival rate, followed by implant failure rate and biological complications such as bleeding on probing and probing pocket depths. Only cumulative implant survival rate data allows meta-analysis revealing a positive effect size (from 0.052 (fixed) to 0.042 (random)), which means that short implant appears to be a successful treatment option. Mechanical complications and crown-to-implant (C/I) ratio measurement were also commonly described, however, considering the available evidence; no strong conclusions could be drawn since different methods were used to assess each parameter. By means of this literature review, a standard evaluation scheme is proposed, being helpful to regiment further investigations and comparisons on future studies.

Long-term Short Implants Performance: Systematic Review and Meta-Analysis of the Essential Assessment Parameters

Lack of standard criteria in the outcome assessment makes it difficult to draw conclusions on the clinical performance of short implants and, under these circumstances, determine the reasons for implant failure. This study evaluated, through a systematic review of the literature and meta-analysis, the essential parameters required to assess the long-term clinical performance of short and extra-short implants. Electronic databases (Pubmed-MEDLINE, Cochrane Library Database, Embase, and Lilacs) were searched by two independent reviewers, without language limitation, to identify eligible papers. References from the selected articles were also reviewed. The review included clinical trials involving short dental implants placed in humans, published between January 2000 and March 2014, which described the parameters applied for outcome's measurements and provided data on survival rates. Thirteen methodologically acceptable studies were selected and 24 parameters were identified. The most frequent parameters assessed were the marginal bone loss and the cumulative implant survival rate, followed by implant failure rate and biological complications such as bleeding on probing and probing pocket depths. Only cumulative implant survival rate data allows meta-analysis revealing a positive effect size (from 0.052 (fixed) to 0.042 (random)), which means that short implant appears to be a successful treatment option. Mechanical complications and crown-to-implant (C/I) ratio measurement were also commonly described, however, considering the available evidence; no strong conclusions could be drawn since different methods were used to assess each parameter. By means of this literature review, a standard evaluation scheme is proposed, being helpful to regiment further investigations and comparisons on future studies.

A falta de critérios padronizados para a avaliação dos resultados faz com que seja difícil tirar conclusões sobre o desempenho clínico dos implantes curtos e, nestas circunstâncias, determinar as razões para o fracasso do implante. Este estudo avaliou, através de uma revisão sistemática da literatura, os parâmetros essenciais necessários para avaliar o desempenho clínico em longo prazo de implantes curtos e extra-curtos. Bases de dados eletrônicas (PubMed-MEDLINE, Base de dados da Biblioteca Cochrane, Embase e Lilacs) foram avaliadas por dois revisores independentes, sem limitação da linguagem, de modo a identificar artigos elegíveis. As referências dos artigos selecionados foram também analisadas. A revisão incluiu estudos clínicos, publicados entre janeiro de 2000 e março de 2014, envolvendo implantes dentais curtos, instalados em seres humanos, nos quais foram descritos os parâmetros utilizados para mensuração dos resultados e fornecidos dados sobre as taxas de sobrevivência. Treze estudos metodologicamente aceitáveis foram selecionados, sendo identificados 24 parâmetros. Os parâmetros avaliados com maior frequencia foram a perda óssea marginal e a taxa cumulativa de sobrevivência do implante, seguida pela taxa de falha dos implantes e complicações biológicas, tais como sangramento à sondagem e profundidade de sondagem. Apenas a taxa cumulativa de sobrevivência dos implantes permitiu a meta-análise revelando efeito positivo (variação de 0.052 (efeito fixo) até 0.042 (efeito aleatório)), demonstrando que os implantes curtos parecem ser uma opção de tratamento bem sucedida. Complicações mecânicas e a mensuração da proporção coroa-implante foram também referidas, entretanto, considerando-se as evidências disponíveis, não se pode chegar a fortes conclusões, pois diferentes métodos foram utilizados para avaliar cada parâmetro. Por meio desta revisão da literatura, um esquema padronizado de avaliação é proposto, sendo útil para arregimentar ...

Implant-retained removable partial dentures: an 8-year retrospective study.

PURPOSE: To evaluate the long-term outcomes of removable partial dentures (RPDs) retained (but not supported) by dental implants. MATERIALS AND METHODS: We retrospectively evaluated 32 consecutive patients who received implant-retained RPDs. Each patient received one to four endosseus implants; the sample included a total of 64 implants. Follow-up was conducted for a minimum of 8 years, during which satisfaction, implant survival, and prosthetic success were evaluated. RESULTS: Patient satisfaction systematically increased. The implant success rate was 93.75%, and 100% of the prostheses were successful. CONCLUSION: Implant-retained RPDs are a reliable intermediate solution that can reduce biological and economic costs while maintaining implant treatment benefits and the ease of RPD procedures.

Dimensional tolerances and assembly accuracy of dental implants and machined versus cast-on abutments.

BACKGROUND: The clinical application of prosthetic components obtained by different manufacturing processes lacks technological foundation: the dimensional tolerance of individual parts and their assembly accuracy are not known. The rotational misfit (RM) of the hexagonal connection is critical in single-tooth implant restorations, but no standard control procedures are available for its evaluation. PURPOSE: The research aimed at proposing a new protocol for the dimensional assessment of implant-abutment connections, based on noncontact measurement and statistical data processing. The procedure was applied to machined- and cast-on abutments, as well of the matching implants. MATERIALS AND METHODS: Three groups of five abutments each were studied: machined titanium abutments, pre-machined calcinable abutments before casting procedures and the same specimens after casting. A group of five corresponding implants was considered as well. Twice the apothem was measured on each hexagon through an optical measuring microscope. The data were processed to obtain the international tolerance (IT) grade. The RM was then calculated using the apothems of the external and the internal hexagon. RESULTS: All the components were classified between IT8 and IT9, and the maximum RM was around 3-4° for all the assemblies, inferior to the critical limits for the screw joint stability. CONCLUSION: An original measuring protocol was developed, independent of parts assembly and based on ITs. An objective dimensional characterization of prosthetic components and assemblies has been achieved, which is the basis for their reliability in clinical applications.

A new generation of sterile and radiopaque impression materials: an in vitro cytotoxicity study.

Impression materials are largely used to record the geometry of dental tissue. Hence, the assessment of their possible cytotoxicity is a necessary step in the evaluation of their biocompatibility. The present study is carried out to evaluate the cytotoxicity of a new elastomeric sterile and radiopaque impression material. Human gingival fibroblasts, cultured in vitro are exposed directly to Elite Implant in three different viscosities, heavy, medium, and light. At 3, 9, 24, 48, and 72 h, the cellular proliferation is evaluated. In parallel, human gingival fibroblasts are exposed indirectly by means of fluid extracts of Elite Implant. The cellular viability is evaluated by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide, (MTT) assay (Sigma, St Louis, Mo). The gingival fibroblasts proliferation and viability are unaffected by the presence of Elite Implant. This new impression material may represent a safe medical device for clinical and surgical applications. In addition, this material is radiopaque and, thus, can be identified radiographically.