Effect of a modified laminate veneer preparation design on absolute margin discrepancy and marginal overhang.

STATEMENT OF PROBLEM: Veneer preparation designs impact veneer accuracy. However, whether a modified design could reduce absolute margin discrepancy and marginal overhangs is unclear. PURPOSE: The purpose of this in vitro study was to investigate whether a modified veneer preparation design enhances the absolute margin discrepancy and marginal overhang. MATERIAL AND METHODS: The absolute margin discrepancy and the marginal overhang of 3 different veneer preparation designs on a typodont tooth (n=20): feather edge, shoulder, and shoulder with wings were measured. The feather edge design was prepared first and subsequently modified to create the shoulder and shoulder with wings preparations. Ceramic veneers were fabricated using computer-aided design and computer-aided manufacture with each veneer assessed for fit before cementation. Ten specimens were cut vertically, and 10 were cut horizontally in each group. The absolute margin discrepancy and marginal overhangs were measured for each cross-section with scanning electron microscopy. Descriptive data analysis and hypothesis testing were conducted using the nonparametric Kruskal Wallis test (α=.05). RESULTS: On the vertical sections, the shoulder with wings preparation had the best absolute margin discrepancy and overhang. The design was also best for mesial overhang and mesial absolute margin discrepancy when measuring horizontally. CONCLUSIONS: The shoulder with wings preparation design produced the smallest cervical absolute margin discrepancy and overhang. This design also produced absolute margin discrepancy and overhangs comparable with those of the shoulder design in the proximal areas.

Accuracy of digitally coded healing abutments: A systematic review.

The aim of this systematic review was to evaluate the in vitro accuracy of dental implant impressions taken using digitally coded healing abutments (CHAs) compared with impressions taken with conventional techniques (CI) and/or within the CHA group at varying degrees of angulations for multiple implant units. Two independent reviewers conducted a systematic electronic search in the MedLine, PubMed, Google Scholar, Cochrane Library, Web of Science, and Scopus databases. Some of the employed key terms, combined with the help of Boolean operators, were: "digitally coded healing abutments", "encode healing abutment", "dental implants", "impression accuracy", "digital impression", and "conventional impression". Publication dates ranged from January 2010 to November 2022. A total of 7 articles fulfilled the inclusion criteria: 6 studies compared the accuracy of CHA with conventional pick-up impression techniques, and one study only used CHAs at different angulations and heights to compare accuracy within the group. The results were divided into Group A (elastomeric impression of CHA) and Group B (CHA + Intraoral scanner). According to the results of this systematic review, elastomeric impression of CHA performed poorly when compared to CI for multiple implants, although an intraoral scan of CHA appears to be more accurate. Within the CHA group, the angulation and visible height of CHA play a significant role in impression accuracy. However, more studies are needed before CHA can be recommended for all non-parallel multiple implant-supported restorations.

Factors influencing success rate of ceramic veneers on endodontically treated anterior teeth: A systematic review.

STATEMENT OF PROBLEM: More conservative restorative approaches have been advocated for nonvital anterior teeth as an alternative to complete coverage crowns to maximize the preservation of tooth structure. Systematic reviews that investigated factors influencing the success rate of porcelain veneers on endodontically treated anterior teeth are lacking. PURPOSE: The purpose of this systematic review was to investigate factors influencing the success rate of porcelain veneers on endodontically treated anterior teeth. MATERIAL AND METHODS: Searches were performed across Medline/PubMed, Google Scholar, Scopus, and Web of Science electronic databases. In addition, articles were hand searched from references of systematic reviews concerning porcelain veneers and endodontically treated teeth. RESULTS: After screening and applying the eligibility, inclusion, and exclusion criteria, 7 articles met the inclusion criteria. Factors that could positively influence the success rate of endodontically treated anterior veneered teeth were immediate dentin sealing, labially positioning of the endodontic access cavity, and incorporating fiber posts. CONCLUSIONS: The use of fiber posts and labial positioning of the endodontic access cavity could positively influence the success rate of porcelain veneers on endodontically treated teeth. The effect of immediate dentin sealing on the survival rate of endodontically treated veneered teeth is still unclear and further research is needed.

Efficacy and safety of Botulinum toxin A for improving esthetics in facial complex: A systematic review.

AIM: To evaluate efficacy and safety of Botulinum toxinA for improving esthetics in the facial complex and correlating them to the dosage and side effects through a systematic review. METHODS: A literature search was performed using PubMed, Medline, Web of Sciences, and Scopus databases. Quality of studies was appraised through the GRADE system. This review follows the 'Preferred reporting items for systematic review and meta-analysis protocols' (PRISMA-P) 2015 statement. Efficacy was analyzed through improvement rate and effect sizes. Graphical comparison of efficacy and ocular adverse effects (adverse effects around the eye) at various anatomical locations was made by calculating the average improvement rate and adverse events. RESULTS: Twenty-five studies were included in this systematic review after application of the inclusion criteria. Moderate to severe cases in glabellar, lateral canthal, and forehead regions showed higher improvement rates between 20U to 50U, with an effect lasting up to 120 days. Gender and age seemed to have a direct effect on efficacy. Headaches were the most common adverse effect, followed by injection site bruising; all adverse effects resolved within 3-4 days. CONCLUSIONS: Treatment with Botulinum toxinA to enhance esthetics of facial complex is efficient and safe at all recommended dosages. Presence of complexing proteins influenced the efficacy of BoNT-A. undesirable muscular adverse effects around the eyes were more predominant when treating the glabellar region. There was no correlation found between the BoNT-A dosage and side effects, however, an increase in dosage did not always lead to an increase in efficacy.

Efficacy and safety of Botulinum toxin A for improving esthetics in facial complex: A systematic review

Abstract Aim: To evaluate efficacy and safety of Botulinum toxinA for improving esthetics in the facial complex and correlating them to the dosage and side effects through a systematic review. Methods: A literature search was performed using PubMed, Medline, Web of Sciences, and Scopus databases. Quality of studies was appraised through the GRADE system. This review follows the 'Preferred reporting items for systematic review and meta-analysis protocols' (PRISMA-P) 2015 statement. Efficacy was analyzed through improvement rate and effect sizes. Graphical comparison of efficacy and ocular adverse effects (adverse effects around the eye) at various anatomical locations was made by calculating the average improvement rate and adverse events. Results: Twenty-five studies were included in this systematic review after application of the inclusion criteria. Moderate to severe cases in glabellar, lateral canthal, and forehead regions showed higher improvement rates between 20U to 50U, with an effect lasting up to 120 days. Gender and age seemed to have a direct effect on efficacy. Headaches were the most common adverse effect, followed by injection site bruising; all adverse effects resolved within 3-4 days. Conclusions: Treatment with Botulinum toxinA to enhance esthetics of facial complex is efficient and safe at all recommended dosages. Presence of complexing proteins influenced the efficacy of BoNT-A. undesirable muscular adverse effects around the eyes were more predominant when treating the glabellar region. There was no correlation found between the BoNT-A dosage and side effects, however, an increase in dosage did not always lead to an increase in efficacy.

Resumo Objetivo: Avaliar a eficácia e segurança da toxina botulínica-A para melhorar a estética no complexo facial e correlacioná-la com a dosagem e os efeitos secundários através de uma revisão sistemática. Métodos: Foi realizada uma pesquisa bibliográfica utilizando bases de dados PubMed, Medline, Web of Sciences, e Scopus. A qualidade dos estudos foi avaliada através do sistema GRADE. Esta revisão segue a declaração "Preferred reporting items for systematic review and meta-analysis protocols" (PRISMA-P) 2015. A eficácia foi analisada através da taxa de melhoria e da dimensão dos efeitos.A comparação gráfica da eficácia e dos efeitos adversos oftalmológicos (efeitos adversos em torno do olho) em vários locais anatômicos foi feita através do cálculo da taxa média de melhoria e dos eventos adversos. Resultados: Vinte e cinco estudos foram incluídos nesta revisão sistemática após a aplicação dos critérios de inclusão. Casos moderados a graves em regiões glabelares, canais laterais e testa mostraram taxas de melhoria mais elevadas entre 20U a 50U, com um efeito que durou até 120 dias. O sexo e a idade mostraram ter efeito direto na eficácia. As dores de cabeça foram o efeito adverso mais comum, seguido de hematomas no local da injecção; todos os efeitos adversos foram resolvidos em 3-4 dias. Conclusões: O tratamento com toxina botulínica-A para melhorar a estética do complexo facial é eficiente e seguro em todas as dosagens recomendadas. A presença de proteínas complexas influenciou a eficácia do BoNT-A. Os efeitos adversos musculares indesejáveis à volta dos olhos foram mais predominantes no tratamento da região glabelar. Não foi encontrada qualquer correlação entre a dosagem de BoNT-A e os efeitos secundários, contudo, um aumento da dosagem nem sempre levou a um aumento da eficácia.

Stress distribution within the ceramic veneer-tooth system with butt joint and feathered edge incisal preparation designs.

OBJECTIVE: This in-vitro study aims to study the stress distribution within the ceramic veneer-tooth system with two incisal preparation designs-butt joint (BJ) and feathered edge (FE), and to correlate these findings to the results of our previous published load-to-failure study. METHODS: Six photoelastic models were fabricated with an epoxy resin material (West System 105 Epoxy Resin/205 Fast Hardener, West System) to represent BJ and FE preparation configurations at 0° and 20° loading angulations. Lithium disilicate ceramic veneers (IPS e.max CAD, Ivoclar Vivadent) were bonded to the BJ and FE photoelastic models using resin cement (IPS Variolink Esthetic, Ivoclar Vivadent). Each model was loaded using an Instron Universal Testing Machine at the incisal edge at a cross-head speed of 0.25 mm/min till 100 N. RESULTS: BJ photoelastic model had more uniform distribution compared with FE photoelastic models under 0° and 20° loading angulations. CONCLUSION: Parallel to the results of our earlier load-to-failure published study, both incisal preparation designs affect stress distribution within the ceramic veneer-tooth system. BJ photoelastic model demonstrated a more uniform distribution compared with FE photoelastic model. CLINICAL SIGNIFICANCE: BJ incisal preparation design has more uniform stress distribution than FE preparation design within the ceramic veneer-tooth system.

Influence of build angulation on the mechanical properties of a direct-metal laser-sintered cobalt-chromium used for removable partial denture frameworks.

STATEMENT OF PROBLEM: Direct-metal laser-sintering (DMLS) technologies are being used to manufacture removable partial denture frameworks; however, the build parameters are not well documented. PURPOSE: The purpose of this in vitro study was to investigate the impact of 3 different build angulations on a dental cobalt-chromium (Sint-Tech ST2724G) alloy by comparing the tensile properties and nanoindentation hardness. The null hypothesis was that no change would be found in the tensile properties of the different build angulation groups. MATERIAL AND METHODS: Dumbbell-shaped tensile specimens were produced by using stereolithographic models in accordance with American Society for Testing and Materials testing standard E8/E8M-16ae1. Specimens (n=10) were fabricated by using DMLS additive manufacturing with 3 different angulations (0, 45, and 90 degrees). Tensile testing was carried out to assess yield strength (0.2% permanent offset), elongation (%) at failure, and ultimate tensile strength (GPa). Scanning electron microscope (SEM) images were used to analyze the fracture surfaces. One 10×10×10 mm cube specimen at each orientation was prepared, and nanoindentation was used to determine hardness and elastic modulus. One-way ANOVA was used to evaluate the overall effects with interaction between groups and post hoc testing applied where the interaction was statistically significant (α=.05). RESULTS: The 45-degree build angulation resulted in the lowest mean elastic modulus of 213.3 GPa and the highest tensile strength of 1180.9 MPa. The 90-degree build angulation resulted in the highest mean elongation of 10.6% and the highest elastic modulus of 234.0 MPa. Within comparison of the different angulations indicated that various groups had statistically significant differences (P<.05). The SEM analysis indicated different fracture topography among the different build angles. CONCLUSIONS: The cobalt-chromium dental alloy manufactured by DMLS produced favorable mechanical properties. The SEM analysis combined with the tensile test results suggest that the direction of the build angle in relation to the laser melt pattern does impact the mechanical properties of the alloy.

Patient satisfaction with esthetics, phonetics, and function following implant-supported fixed restorative treatment in the esthetic zone: A systematic review.

OBJECTIVE: To determine patient satisfaction with esthetics, phonetics, and function following implant-supported fixed restorative treatment in the esthetic zone by measuring the Oral Health Related Quality of Life (OHRQoL). MATERIALS AND METHODS: This systematic review follows the "Preferred reporting items for systematic review and meta-analysis protocols" (PRISMA-P) 2015 statement. Studies were searched in the databases Ovid, PubMed, Web of Science, Scopus, and the Cochrane Library. The quality of the studies included in the review was scored using the GRADE system. The impact of the findings was analyzed by calculating effect size and standardization of results across different OHRQoL measurements was achieved by calculating the percentage equivalent. RESULTS: A total of 13 studies were selected to be included in his systematic review after application of the inclusion criteria. A total of six studies recorded pre- and post-treatment OHRQoL results, while the remaining seven studies provided only post-treatment results. CONCLUSIONS: This review concluded that implant-supported fixed restorations in the esthetic zone have an overall positive impact on OHRQoL. However, patient satisfaction from this treatment reduced as the number of missing teeth replaced by implants was increased. CLINICAL SIGNIFICANCE: When implant-supported fixed restorations are being planned in the esthetic zone, dentists need to consider the patient's perception and the subsequent impact of these restorations on the patient's quality of life. Clinicians can be assured that patient OHRQoL will increase; however, clinicians should also keep in mind the importance of the gingival frame. Furthermore, they should be aware of the challenges when planning cases with larger numbers of implants in the esthetic zone as this could lead to a lowering of a patient QoL.

Over-the-Counter Tooth Whitening Agents: A Review of Literature.

There is an increased accessibility of over-the-counter (OTC) whitening agents with very little data in the literature regarding their effectiveness. This review was done to determine their effectiveness of the predominant OTC whitening agents from 2006 until 2018 where a comparison of each agent was made with a placebo, no treatment or with other OTC whitening agents. The major categories of OTC whitening agents such as dentifrices, whitening strips and paint on gels. Dentist prescribed bleaching applied at home and in-office bleaching studies and studies that demonstrated whitening products to participants were excluded. Articles were searched for in the databases of Medline (Ovid), PubMed, the Cochrane Library and Cochrane Central Register of Controlled Trials. Twenty-four articles were included in the systematic review and the quality of studies was determined by the GRADE (Grading of Recommendations, Assessment, Development and Evaluations) ranking criteria. Compared to other OTC, strips are reported to be effective. Two studies determined whitening strips to be effective. Whitening strips have been shown to be effective when compared with placebos and other OTC whitening agents. Dentifrices are effective in changing the shade of the tooth "by removing extrinsic stains" when compared to a placebo and non-whitening dentifrices, but they are not as effective in comparison to whitening strips. There is a lack of evidence with regards to the effectiveness of paint-on gels. While there is some evidence that OTC can alter shade in the short term, there is a need for better-designed studies.

Over-the-counter tooth whitening agents: a review of literature

Abstract There is an increased accessibility of over-the-counter (OTC) whitening agents with very little data in the literature regarding their effectiveness. This review was done to determine their effectiveness of the predominant OTC whitening agents from 2006 until 2018 where a comparison of each agent was made with a placebo, no treatment or with other OTC whitening agents. The major categories of OTC whitening agents such as dentifrices, whitening strips and paint on gels. Dentist prescribed bleaching applied at home and in-office bleaching studies and studies that demonstrated whitening products to participants were excluded. Articles were searched for in the databases of Medline (Ovid), PubMed, the Cochrane Library and Cochrane Central Register of Controlled Trials. Twenty-four articles were included in the systematic review and the quality of studies was determined by the GRADE (Grading of Recommendations, Assessment, Development and Evaluations) ranking criteria. Compared to other OTC, strips are reported to be effective. Two studies determined whitening strips to be effective. Whitening strips have been shown to be effective when compared with placebos and other OTC whitening agents. Dentifrices are effective in changing the shade of the tooth "by removing extrinsic stains" when compared to a placebo and non-whitening dentifrices, but they are not as effective in comparison to whitening strips. There is a lack of evidence with regards to the effectiveness of paint-on gels. While there is some evidence that OTC can alter shade in the short term, there is a need for better-designed studies.

Resumo Há um aumento da acessibilidade dos agentes clareadores de venda livre com poucos dados na literatura sobre sua eficácia. Esta revisão foi feita para determinar a eficácia dos agentes clareadores de venda livre predominantes de 2006 a 2018, onde foi feita uma comparação de cada agente com um placebo, sem tratamento ou com outros agentes clareadores de venda livre. As principais categorias de agentes clareadores de venda livre, como dentifrícios, tiras branqueadoras e géis. Estudos em que o dentista prescreveu clareamento caseiro e em consultório, e estudos que demonstraram os agentes clareadores para os participantes. Os artigos foram pesquisados ​​nas bases de dados do Medline (Ovid), PubMed, Cochrane Library e Cochrane Central Register of Controlled Trials. Vinte e quatro artigos foram incluídos na revisão sistemática e a qualidade dos estudos foi determinada pelo critério de classificação GRADE (Classificação de Recomendações, Avaliação, Desenvolvimento e Avaliações). Em comparação com outros clareadores de venda livre, as tiras são relatadas como eficazes. Dois estudos determinaram que as tiras de clareamento são eficazes. As tiras de clareamento mostraram-se eficazes quando comparadas com placebos e outros agentes clareadores de venda livre. Os dentifrícios são eficazes na mudança da tonalidade do dente "removendo manchas extrínsecas" quando comparados a dentifrícios com placebo e sem clareamento, mas não são tão eficazes em comparação com as tiras de clareamento. Há uma falta de evidência com relação à eficácia dos géis de tinta. Embora exista alguma evidência de que os clareadores de venda livre possa alterar a tonalidade no curto prazo, há necessidade de estudos melhor projetados.

A randomized controlled clinical trial comparing the use of displacement cords and aluminum chloride paste.

OBJECTIVES: This clinical study measured the change in opening and height of the displaced gingiva using paste and cord retraction materials for definitive impression making of natural teeth and assessed if they were comparable and clinically acceptable. METHODS: Impressions of 4 maxilla premolars from 10 participants were taken using a split-mouth protocol. All participants were free of periodontal disease, had a thick biotype, a minimal of 3 mm height of keratinized gingival tissue and gingival sulci depths of 2 mm. The bleeding index (BI), gingival index (GI) plaque index (PI), sulcular depth, level of attachment and tooth sensitivity were recorded at baseline, just after retraction, at 24 hours and at 2 weeks. Impressions were poured in stone and then after initial analysis were cross-sectioned to allow measurements of the gingival height change and gap size to be recorded. RESULTS: The paste produced a slightly smaller gap compared to the cord (0.041 mm less, P = .014) whilst the mean displacement for the cord was 0.282 mm and paste was 0.241 mm respectively. Gingival height with the paste was 0.047 mm lower than that achieved by the cord (P = .208). CONCLUSIONS: Cord and paste retraction produced comparable clinically acceptable gingival gaps, with the cord producing statistically larger gap size. CLINICAL SIGNIFICANCE: The cord and paste retraction materials produced comparable clinically acceptable gingival retraction.

Effect of incisal preparation design on load-to-failure of ceramic veneers.

OBJECTIVE: This in vitro study aims to evaluate load-to-failure of ceramic veneers with butt joint (BJ) and feathered edge (FE) incisal preparation designs, and to correlate these results to the failure mode of the restorations. MATERIALS AND METHODS: One hundred and forty-eight typodont teeth (customized Nissin A25A-UL19B) were divided into two different preparation configurations BJ and FE and two different loading angulations, 0° and 20°. Lithium disilicate ceramic veneers (IPS e.max CAD, Ivoclar Vivadent) were milled using computer-aided-design-and-computer-aided-manufacturing (CAD/CAM) techniques. Veneers were bonded to typodont teeth with resin cement (IPS Variolink Esthetic, Ivoclar Vivadent). Each group was loaded at the incisal edge using an Instron Universal Testing Machine at a crosshead speed of 0.01 mm/s till failure. RESULTS: Pairwise comparison showed veneers from the BJ groups had a significantly higher load-to-failure value compared to the FE groups. Veneers with a FE preparation design loaded at 20° angulation had the lowest load-to-failure value. CONCLUSIONS: Within the limitations of the present study, both incisal preparation designs and loading angulations have significant effects on the load-to-failure values of ceramic veneers. BJ group exhibits a significantly higher load-to-failure value compared to the FE group. CLINICAL SIGNIFICANCE: BJ incisal preparation is preferred over FE preparation design.

Bonding strengths to porcelain: An in vitro study of ultrasonic and conventional tooth preparation and etching.

OBJECTIVE: To compare the bond strength of porcelain to enamel and dentin preparations finished with either ultrasonic instruments or diamond burs, with or without acid etching. MATERIALS AND METHODS: A total of 140 extracted bovine incisor teeth were divided into two groups, enamel and dentin. A split tooth model was employed: each tooth having a randomly allocated combination of diamond burs, ultrasonic instrument, etching, and no etching treatments on their labial surface. Lithium disilicate glass ceramic specimens were bonded to the prepared surfaces and tensile testing was carried out. Force was applied to failure, and linear mixed models were used to analyze the data. RESULTS: Etching increased the bond strength of the dentin samples by 7.63 MPa (P < 0.001). When bonding to dentin, ultrasonic instrument preparation produced a 2.88 MPa greater bond strength compared to burs (P < 0.001). CONCLUSION: Ultrasonic preparation produced greater bond strengths compared to rotary instruments. Etching improved the bond strength of all preparations, with enamel having consistently greater bonding values than dentin.

The effect of different geometric shapes and angles on the fracture strength of IPS e.max computer-aided designed ceramic onlays: An in vitro study.

STATEMENT OF PROBLEM: The current ceramic onlay preparation techniques for cuspal areas involve the reduction of cusps following the cuspal anatomy and the removal of all sharp angulations. However, there is little research literature studying the effect of occlusal preparation angles. Furthermore, there is no recent literature on the effect of angulations on IPS e.max computer-aided designed (CAD) (e.max) ceramic onlays. PURPOSE: The purpose of this study is to investigate the effect of geometric cuspal angulation and different internal preparation angles on the fracture strength of e.max CAD ceramic onlays. MATERIALS AND METHODS: Sharp (33° and 22°) and round (33° and 22°) preparations were tested, each group having 10 specimens. e.max ceramic onlays were milled, sintered, glazed, and then bonded onto geometric tooth models. Fracture strength was measured at the initial fracture with a universal testing machine. The load was applied laterally to the central fossa (2-point contact) and vertically to the cusp peak (1-point contact). RESULTS: A reduced cuspal angulation of 22° resulted in a stronger ceramic onlay than a 33° angulation when laterally loaded (P = 0.001). The presence of sharp angles weakened the ceramic significantly for both the 22° preparation (P = 0.0013) and 33° preparation (P = 0.0304). CONCLUSION: This in vitro study found that preparation angles of 22° resulted in superior fracture strength during central fossa loading and that rounding the preparation resulted in significantly higher fracture strength when a cusp peak load was applied. When the cusp tip loading is applied, the preparation angle does not appear to influence the fracture strength.

Incisal preparation design for ceramic veneers: A critical review.

BACKGROUND: The authors reviewed and identified the evidence for the various incisal preparation designs for ceramic veneers. TYPES OF STUDIES REVIEWED: The authors searched MEDLINE with PubMed and Ovid to identify any articles in the English language related to the topic up through March 2017 using a combination of key words: "porcelain veneer or ceramic veneer or dental veneer or labial veneer" AND "preparation," NOT "composite veneer," NOT "crown," NOT "implant," NOT "fixed partial denture or bridge or denture," NOT "porcelain-fused-to-metal," NOT "marginal gap or fit." RESULTS: In vitro studies showed that the palatal chamfer preparation design increases the risk of developing ceramic fractures. The butt joint preparation design had the least effect on the strength of the tooth. CONCLUSIONS: Surveys show the 2 most common incisal preparation designs provided are butt joint and feathered-edge. Clinical studies have identified that incisal ceramic is the most common location of ceramic fracture. In addition, there is a lack in standardization of the modeling structures and type of finite element analysis. PRACTICAL IMPLICATIONS: The evidence seems to support the use of butt joint over palatal chamfer incisal preparation design. Fracture or chipping is the most frequent complication and the risk increases with time. Incisal ceramic is the most common location of ceramic fracture.

The periodontal restorative interface: esthetic considerations.

Esthetic considerations are a significant contributing factor in the management of prosthodontic cases and an interdisciplinary approach is often necessary to achieve an optimal result. The visible soft-tissue architecture plays a key role in developing an esthetic smile. Furthermore, an understanding of the relationship between the restorative margin and the gingiva is important for long-term stability of the result. The gingival architecture and gingival health are important for ensuring optimal esthetics following prosthodontic work and close attention to both soft and hard tissues around the teeth, before, during and after restorative procedures, will greatly improve the likelihood of a successful outcome. Moreover, knowing the options available in periodontal plastic surgery is important in esthetic dentistry today. The relevant literature related to restorative and surgical procedures when performing esthetic dentistry are reviewed in this article, and different approaches are illustrated with appropriate cases to explain the treatment approach that was utilized to improve the esthetic appearance of the case.

New Ti-Alloys and Surface Modifications to Improve the Mechanical Properties and the Biological Response to Orthopedic and Dental Implants: A Review.

Titanium implants are widely used in the orthopedic and dentistry fields for many decades, for joint arthroplasties, spinal and maxillofacial reconstructions, and dental prostheses. However, despite the quite satisfactory survival rates failures still exist. New Ti-alloys and surface treatments have been developed, in an attempt to overcome those failures. This review provides information about new Ti-alloys that provide better mechanical properties to the implants, such as superelasticity, mechanical strength, and corrosion resistance. Furthermore, in vitro and in vivo studies, which investigate the biocompatibility and cytotoxicity of these new biomaterials, are introduced. In addition, data regarding the bioactivity of new surface treatments and surface topographies on Ti-implants is provided. The aim of this paper is to discuss the current trends, advantages, and disadvantages of new titanium-based biomaterials, fabricated to enhance the quality of life of many patients around the world.

Correlation of pressure and displacement during gingival displacement: An in vitro study.

STATEMENT OF PROBLEM: Although numerous gingival displacement materials are available, information is limited regarding the pressures that can atraumatically produce sufficient gingival displacement for a successful impression. PURPOSE: The purpose of this in vitro study was to measure pressure and the resulting movement of artificial gingiva during simulated gingival displacement. MATERIAL AND METHODS: An idealized tooth model was made from acrylic resin and polyvinyl siloxane to simulate the free gingiva, sulcus, and attachment. The pressure and displacement achieved by 3 materials (Expasyl, Expasyl New, and KnitTrax Cord) were measured. A stereoscopic digital measuring microscope was used to quantify the space generated by the displacement material. A pressure gauge was used to measure the corresponding pressures. RESULTS: The injection of Expasyl resulted in a displacement distance of 1.31 mm, Expasyl New 1.07 mm, and KnitTrax Cord 0.85 mm, which are within acceptable clinical parameters. The correlation between pressure and gap showed that Expasyl and Expasyl New behaved similarly, while KnitTrax Cord was different. Expasyl, Expasyl New, and KnitTrax Cord all had maximum pressures that would be considered atraumatic to the epithelial attachment. CONCLUSIONS: An increase in pressure resulted in an increase in displacement for the 2 paste materials. However, contrary to expectation, displacement decreased as pressure increased for the cord material.

Effect of Air-Polishing on Titanium Surfaces, Biofilm Removal, and Biocompatibility: A Pilot Study.

PURPOSE: The aims of this in vitro study were to evaluate morphological changes induced by glycine powder air-polishing on titanium surfaces, biofilm removal, and biocompatibility. MATERIAL AND METHODS: Titanium grade IV discs were allocated into two groups: (1) discs without biofilm and (2) discs for Streptococcus mutans biofilm formation. Discs in each group were further subdivided into (a) no treatment and (b) air-polishing treatment with glycine powder. Discs were characterized by scanning electron microscopy (SEM), electron-dispersive spectroscopy (EDS), and confocal microscopy. Bacterial biofilms were quantified using a crystal violet dye-binding assay. Biocompatibility was evaluated by measuring the coverage and viability of L929 fibroblast cells cultured on the discs. RESULTS: Air-polishing increased the roughness of treated discs (P < 0.05). EDS analysis did not show significant differences in the chemical composition of treated and nontreated discs. The amount of residual biofilm on treated discs was 8.6-fold lower than untreated controls (P < 0.05). Coverage of treated discs by fibroblasts was half that of untreated discs (P < 0.05) although both groups had the same cell viability. CONCLUSIONS: Air-polishing removed a significant amount of biofilm from titanium surfaces. The "polishing" was accompanied by increased surface roughness, but there were no changes in chemical and elemental compositions, nor the biocompatibility.

Effectiveness of Disposable (Single-use) Tips for Dental Air-water Syringes.

BACKGROUND: Single-use dental syringe (SUS) tips eliminate cross-infection risks. Many dental materials are moisture sensitive; therefore bonding could be affected by remaining moisture from SUS tips. METHODS: An air-water syringe was calibrated to 50 PSI and the air pressure measured. SUS tips were then attached and pressure re-measured. Seven tips were tested; moisture content and spray pattern were investigated. Ethical approval was granted. Twenty third molar teeth were sectioned, stored in phosphate buffered saline and randomly allocated into groups with a SUS tip. They were mounted in acrylic and polished. Specimens were dried with a tip under standardised conditions, treated using a 3-step etch-prime-bond technique, then had a post bonded perpendicular to the dentine surface. The force to detach them was measured. Data were analysed using one-way analysis of variance (ANOVA) and Chi-squared tests. RESULTS: The difference in output pressure between groups proved significant (p < 0.001). Tensile force at failure was significantly different between groups (p = 0.19). CONCLUSIONS: The pressure output of the syringe and bond strength are influenced by the SUS tip.