Influence of posts and cores on light transmission through different all-ceramic crowns: spectrophotometric and clinical evaluation

PURPOSE: The influence of different types of posts and cores on light transmission through all-ceramic crowns was assessed by spectrophotometric analysis and clinical evaluation. MATERIALS AND METHODS: Three extracted natural teeth were replicated in acrylic resin, with roots prepared to receive standardized posts and cores. Using a silicone impression material as a template, various prosthodontic reconstructions were obtained by combining four types of posts and cores (polished and matte-finished gold alloy, all-ceramic, and ceramized metal alloy) and three types of all-ceramic crowns (IPS-Empress 2 surface-colored, IPS-Empress 2 stratified, and In-Ceram). The spectrophotometric analysis was performed in the dark at 25 degrees C. The teeth were backlit with an incandescent lamp at the color temperature of A illuminant and shielded to avoid spurious light entering the spectrophotometer. The transmitted light was analyzed in terms of luminance at four points of the sample surface (cervical, middle, incisal, and proximal). Twelve measurements were performed for the natural teeth, and 144 were performed for the artificial teeth. RESULTS: Natural teeth had the highest luminance. Among all-ceramic crowns, surface-colored IPS-Empress 2 had the highest luminance, and stratified IPS-Empress 2 had the lowest. Regarding posts and cores, the luminance was highest with the all ceramic, lower with the ceramized and the polished gold alloy (which had very similar luminance), and lowest with the matte-finished gold alloy. No significant difference among prosthodontic combinations was detected under clinical observation. CONCLUSION: The surface-colored glass ceramic (IPS-Empress 2) was the most translucent crown. At the standard crown thickness used, there were small, significant spectrophotometric, but not clinical, differences among the combinations tested. These findings show no esthetic contraindications for the use of polished gold alloy posts and cores with all-ceramic crowns.     

Guidelines for periodontal prostheses serve esthetic and functional demands: a case report.

Periodontal-prosthesis guidelines have long been defined to specifically address dental reconstructions after moderate to advanced periodontal disease has occurred. More recently, specific dental techniques and materials have shown promise in addressing patients' increasing esthetic demands. However, treatment planning to achieve pleasing results for patients with advanced periodontitis requires a complex, multispecialty approach that is rarely discussed. A case report and literature review illustrate that the original periodontal-prosthesis guidelines not only remain useful today for obtaining esthetic results but also conform to recent understanding of maxillomandibular physiology.     

New all-ceramic indirect post-and-core system

The increasing demand for highly esthetic, biocompatible posts and cores has led to the development of metal-free, post-and-core systems. This article describes and evaluates an indirect method for the fabrication of an all-ceramic post and core.     

The functional and esthetic deficit replaced with an acrylic resin gingival veneer.

Periodontal attachment loss in the maxillary anterior region can often lead to esthetic and functional clinical problems including disproportional and elongated clinical crowns, visible interdental embrasures, and altered linguoalveolar-labiodental consonant production. Assuming fixed prosthetic reconstructions will be chosen to treat these areas, it becomes a hygienic compromise to fill these areas in with porcelain. In the presence of these problems, an acrylic resin gingival veneer is an easily constructed, inexpensive, and practical device to optimize the esthetic and functional outcome in these special situations while permitting cleansibility of the prosthesis and supporting tissues. This article presents a step-by-step technique for the fabrication of a gingival veneer.     

Esthetic enhancement of ceramic crowns with zirconia dowels and cores: a clinical report

There has been an increase in the use of esthetic metal-free ceramic crowns in restoring endodontically treated teeth or teeth with severe coronal destruction. Tooth-colored dowels and cores are used to enhance the esthetic result. This report describes the treatment of a patient with bilateral maxillary supernumerary lateral incisors, a severe malocclusion, and maxillary anterior tooth discoloration. Treatment included heat-pressed, metal-free ceramic crowns supported by zirconia ceramic dowel-and-core foundations.     

Ceramic posts

As a result of ceramics and all-ceram technologies development esthetic inlay core and abutments flooded the market. Their tooth-colored appearance enhances restoration biomimetism principally on the marginal gingiva area. This article reviews indications and types of cores designed for natural teeth and implants.     

An alternative method for fabricating a custom-made metal post with a ceramic core

Abstract –  The restoration of anterior non-vital teeth with metal posts and cores and all-ceramic restorations may lead to compromised esthetics because of the semitranslucence of ceramics and the metallic color of the underlying post and cores. This article presents a technique that combines the optical properties of ceramic cores with the mechanical properties of custom-made cast metal posts. The technique involves heat pressing of the core from leucite-enriched glass-ceramic to the underlying custom-made metal post and may provide additional esthetic benefit for anterior teeth especially with little remaining coronal dentin and with small root volume.     

A preliminary consideration of the glass-ceramic dowel post and core

Both cast ceramic and metal post and cores were made for endodontically treated extracted teeth and restored with ceramic restorations. The ceramic posts did not change the translucency or color of the natural tooth, in contrast to the metal posts, which altered both. A clinical study followed, with eight restorations placed for a mean period of service of 11.3 months. One ceramic post failed early following cementation. This preliminary report indicates that ceramic posts and cores offer excellent esthetic results and may be strong enough for clinical use under normal conditions.     

Zirconia for teeth and implants: a case series

This case series reports on the use of nonsilica-based high-strength full ceramics for different prosthetic indications. Fifty-two consecutive patients received tooth- or implant-supported zirconia reconstructions during a 2-year period. The observation period for reexamination was 12 to 30 months. The most frequent indications were single crowns and short-span fixed partial dentures. A few implant superstructures were screw-retained, whereas all remaining restorations were cemented on natural teeth or zirconia implant abutments. Clinical examination included biologic (probing depths, bleeding on probing) and esthetic (Papilla Index) parameters, as well as technical complications. No implant was lost or caused any problems, but two teeth were lost after horizontal fracture. Overall, the periodontal parameters were favorable. Fractures of frameworks or implant abutments were not observed. Abutment-screw loosening occurred once for one premolar single crown. Furthermore, five implant crowns in the posterior region exhibited chipping of the porcelain veneering material. With regard to esthetics, no reconstructions were considered unacceptable, but three crowns were remade shortly after delivery. In this short-term study, it was observed that biologic, esthetic, and mechanical properties of zirconia were favorable, and the material could be used in various prosthetic indications on teeth or implants.     

Technical failures and some related clinical complications in extensive fixed prosthodontics. An epidemiological study of long-term clinical quality

Three hundred and sixteen fixed partial dentures made in 1975-1976 by 112 general practitioners in Malm?, Sweden, were selected for a questionnaire study of the technical failure rates after 6-7 years. Cariologic, periodontal, endodontic, and esthetic complications were also identified, as were those appearing in the stomatognathic system. The total material consisted of three groups with an approximately equal number of reconstructions. One group consisted of fixed partial dentures with distal abutment teeth, another was formed of fixed prostheses with single cantilever pontic/pontics, and a third consisted of double cantilever pontics. Excluding the 26 reconstructions, which had been made for patients who died (24) or emigrated (2) during the observation period, data was obtained for 97% of the selected restorations. The results showed high rates of cariologic (18-31%), endodontic (5-23%), periodontal (7-12%), esthetic (10-16%), and technical (8-34%) complications. Differences were noted between the groups. For all types of technical failures (fractures and loss of retention) higher frequencies were related to the extent of cantilevering. Direct relationships were found between the technical failure rate and the time in service, the sum of all cantilever extension pontics in the reconstructions, and the state of the pulps of the distal abutments. No relationship was found between the technical failure rate and the status of the dentition in the opposing jaw. The clinical significance of the results obtained is discussed.     

Cements for use in esthetic dentistry

Dental cements are designed to retain restorations, appliances, and post and cores in a stable and, presumably, long-lasting position in the oral environment. Conventional glass ionomer and zinc phosphate cements are among the most popular materials for luting metallic restorations and posts, whereas resin-based cements are preferred for esthetic applications. Successful cementation of esthetic restorations is largely dependent on the appropriate treatment and silane application to the internal surface of the restoration. Clinicians are frequently advised to use three-step total-etch or two-step self-etch adhesive for luting purposes to avoid problems of incompatibility between adhesives and chemical- or dual-cure cements. A reliable cementation procedure can only be achieved if the operator is aware of the mechanisms involved and the material limitations.     

Versatility of vascularized fibula and soft tissue graft in the reconstruction of the mandibulofacial region.

The anatomical region "laterodorsal calf" with the fibula, the flexor muscles and the overlying skin served by the peroneal vessels, is a suitable donor region particularly for combined microsurgical transfer of bone and soft tissue. In a five and a half year period, 59 reconstructions, 39 (66%) with and 20 (34%) without soft tissue transfer, were performed. The versatility and the functional and esthetic results after osseous, osteocutaneous, osteomuscular and osteomyocutaneous tissue transfer are presented.     

Parapulpal pins and their effects on the fracture resistance of pin-retained cores

The bending characteristics of various parapulpal pins, the retention of a parapulpal pin in different core buildup materials, and the fracture resistance of pin-retained cores were investigated in an in-vitro study. In amalgam and composite cores, the use of parapulpal pins produced an increase in fracture resistance. The highest fracture resistance values were observed in amalgam cores, and the lowest fracture strength was exhibited by cores of glass ionomer cements (GICs) containing metallic particles. The different parapulpal pins and their flexural rigidity had little effect on the fracture resistance of the pin-retained cores. For extensive pin-retained cores it appears advisable to use GICs with restraint and, particularly in the case of large-scale bridge reconstructions, only after critical examination of the loading conditions.     

一体化氧化锆桩核修复牙本质肩领不完整前牙牙体缺损临床效果评价

目的 评价一体化氧化锆桩核修复牙本质肩领不完整前牙牙体缺损的临床效果。方法 选择2010年1月至2011年12月在广东省中山市人民医院口腔医疗中心修复科就诊的上前牙牙体大面积缺损牙本质肩领不完整患者40例（40颗患牙）。经完善根管治疗后随机分为A、B两组,每组20例（20颗患牙）。A组采用一体化氧化锆桩核+氧化锆全瓷冠进行修复,B组采用铸造钴铬桩核+钴铬烤瓷全冠进行修复。经过2年的临床追踪随访,观察其临床效果。结果 随访期内,40例患者均能如期复诊。A组所有患者对修复美观效果均示满意;有1例右上中切牙在18个月时出现根折,其余病例均无桩核松动、脱落、折断,无根折,无明显牙龈炎,X线片未见继发性根尖周炎。B组中有9例患者对修复美观效果表示满意,11例患者认为美观效果一般;有2例分别是右上侧切牙在6个月及左上中切牙在15个月时发生根折,1例左上中切牙在24个月时因桩核松动而脱落,3例患牙在12个月和18个月时出现牙龈炎。结论 一体化氧化锆桩核修复牙本质肩领不完整前牙牙体缺损时可获得满意的美观效果及生物相容性,近期临床效果满意。     

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目的评价一体化氧化锆桩核修复牙本质肩领不完整前牙牙体缺损的临床效果。方法选择2010年1月至2011年12月在广东省中山市人民医院口腔医疗中心修复科就诊的上前牙牙体大面积缺损牙本质肩领不完整患者40例（40颗患牙）。经完善根管治疗后随机分为A、B两组,每组20例（20颗患牙）。A组采用一体化氧化锆桩核＋氧化锆全瓷冠进行修复,B组采用铸造钴铬桩核＋钴铬烤瓷全冠进行修复。经过2年的临床追踪随访,观察其临床效果。结果随访期内,40例患者均能如期复诊。A组所有患者对修复美观效果均示满意;有1例右上中切牙在18个月时出现根折,其余病例均无桩核松动、脱落、折断,无根折,无明显牙龈炎,x线片未见继发性根尖周炎。B组中有9例患者对修复美观效果表示满意,11例患者认为美观效果一般;有2例分别是右上侧切牙在6个月及左上中切牙在15个月时发生根折,1例左上中切牙在24个月时因桩核松动而脱落,3例患牙在12个月和18个月时出现牙龈炎。结论一体化氧化锆桩核修复牙本质肩领不完整前牙牙体缺损时可获得满意的美观效果及生物相容性,近期临床效果满意。     

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目前牙齿美学修复是口腔临床中的热点。在对前牙美学缺陷患者的修复治疗中,最重要的是要检查获取患者全部相关的牙齿美学信息,分析患者美学缺陷中的问题,最后做出正确的美学修复设计。本文讨论有关前牙美学修复中前牙美学分析和美学设计中常用的方法、4个重要的美学参数以及露龈笑的病因和治疗。     

Individually Prefabricated Prosthesis for Maxilla Reconstuction.

The reconstruction of maxillofacial bone defects by the intraoperative modeling of implants may reduce the predictability of the esthetic result, leading to more invasive surgery and increased surgical time. To improve the maxillofacial surgery outcome, modern manufacturing methods such as rapid prototyping (RP) technology and methods based on reverse engineeing (RE) and medical imaging data are applicable to the manufacture of custom-made maxillary prostheses. After acquisition of data, an individual computer-based 3D model of the bony defect is gernerated. These data are tranferrred into RE software to create the prosthesis using a computer-aided design (CAD) model, which is directed into the RP machine for the production of the physical model. The precise fit of the prosthesis is evaulated using the prosthesis and skull model. The prosthesis is then directly used in investment casting such as "Quick Cast" pattern to produce the titanium model. In the clincical reports presented here, reconstructions of two patients with large maxillary bone defects during the operations, and surgery time was reduced. These cases show that the prefabrication of a prosthesis using modern manufacturing technology is an effective method for maxillofacial defect reconstruction.     

Randomized controlled clinical trial of customized zirconia and titanium implant abutments for canine and posterior single-tooth implant reconstructions: preliminary results at 1 year of function

Objectives: The aim of this study was to test whether or not customized zirconia abutments exhibit the same survival rates in canine and posterior regions as titanium abutments, and to compare the esthetic result of the two abutment types. Material and methods: Twenty‐two patients with 40 implants in posterior regions were included and the implant sites were randomly assigned to 20 customized zirconia and 20 customized titanium abutments. All‐ceramic (AC) and metal–ceramic (MC) crowns were fabricated. In all except two cases, the crowns were cemented on the abutments using resin or glass‐ionomer cements. Two zirconia reconstructions were screw retained. At baseline, 6 and 12 months, the reconstructions were examined for technical and biological problems. Probing pocket depth (PPD), plaque (Pl) and bleeding on probing (BOP) were assessed and compared with natural control teeth. Furthermore, the difference of color (ΔE) of the peri‐implant mucosa and the gingiva of control teeth was evaluated by means of a spectrophotometer (Spectroshade). The data were analyzed with Student's unpaired t‐test, ANOVA and regression analyses. Results: Twenty patients with 19 zirconia and 12 titanium abutments were examined at a mean follow‐up of 12.6±2.7 months. The survival rate for reconstructions and abutments was 100%. No technical or biological problems were found at the test and control sites. Two chippings (16.7%) occurred at crowns supported by titanium abutments. No difference was found regarding PPD (meanPPD_ZrO2 3.4±0.7 mm, mPPD_Ti 3.3±0.6 mm), Pl (mPl_ZrO2 0.2±0.3, mPl_Ti 0.1±1.8) and BOP (mBOP_ZrO2 60±30%, mBOP_Ti 30±40%) between the two groups. Both crowns on zirconia and titanium abutments induced a similar amount of discoloration of the soft tissue compared with the gingiva at natural teeth (ΔE_ZrO2 8.1±3.9, ΔE_Ti 7.8±4.3). Conclusions: At 1 year, zirconia abutments exhibited the same survival and a similar esthetic outcome as titanium abutments.     

Soft tissue injuries of the face

Traumatic lesions of the soft tissues of the face may have an important social impact in affecting vital functions of the face as well as esthetics. Despite of some tolerance in adapting to tissue loss, major tissue of the face needs to be reconstructed at all levels. Primary treatment is most successful if reconstructions are performed atraumatically, using well vascularized tissues and respecting the esthetic units of the face. Functional structures such as the eye lids, the lips, the facial nerve and the parotid duct should be repaired as a primary procedure. Scar maturation is a prerequisite before performing secondary corrections.     

A pragmatic perspective on reconstructive dentistry and the utilization of posterior all-ceramic crowns

The placement of well over 500 units of all-ceramic crowns with internally supported aluminous porcelain cores, on anterior (37 percent) and posterior (63 percent) teeth, has demonstrated no greater fracture rate than what might be expected from ceramometal crowns. This esthetic option further expands reconstructive vistas. However, this option must be accompanied by inclusive patient management and education, proper examination and integrated comprehensive treatment planning based upon a sound knowledge of the biology and biomechanics of the stomatognathic system.