Laboratory Study of Color Stability of Different Types of Materials for Temporary Constructions.

INTRODUCTION: A temporary construction serves as a preliminary representation of the type and appearance of a future permanent one that is tailored to the patient's requirements. Like any prosthetic construction, it should meet the functional requirements, preserve or improve chewing and speech function. No matter how well maintained a prophylactic and functional prosthetic structure is, it will not be evaluated by the patient unless it retains and restores the existing shape, size and color of the natural teeth. AIM: To determine instrumentally to what extent different colorants change the color of temporary constructions. MATERIALS AND METHODS: Two materials for temporary restoration were tested - Protemp II and Protemp IV, of which a total of 100 test specimens, were fabricated. Under the equal storage conditions of room temperature and no direct access to sunlight, they were exposed to five 100-ml staining solutions: Coca-Cola, coffee (espresso), berry tea, orange juice and red wine in five separate containers. Measurements of color changes in the three areas of the tooth were performed using two spectrophotometric devices - Vita EasyShade and SpectroShade, at different time intervals - immediately before placement in the staining solution, at 1, 4, 7, and 14 days. RESULTS: The results were analysed using the SPSS Statistical Processing Program (SPSS Inc., IBM SPSS Statistics) version 21.0. They were converted to a text file with the converter of the same program. In hypothesis testing, a standard value of p ≤ 0.05 was chosen for the level of significance that rejects the null hypothesis. CONCLUSION: Based on this study, the strong colouring effect of coffee and red wine on these restorations was demonstrated. We can conclude that Protemp IV material showed better color stability compared to Protemp II.

Investigation of adult stainless steel crown longevity as an interim restoration in pediatric patients.

BACKGROUND: Preformed metal crowns, also known as stainless steel crowns (SSC), are utilized for providing full coverage to young permanent teeth and have been used extensively as restorations of primary teeth for approximately 65 years. AIM: Evaluate permanent tooth SSC longevity as an interim restoration for teeth requiring full coverage restoration in pediatric patients. DESIGN: Retrospective chart review from 2006 through 2014 in a hospital-based dental clinic for permanent tooth pre-fabricated crown longevity. One hundred and fifty-five SSCs were evaluated with regard to: age of patient at restoration placement, diagnoses, and duration of crown service. Duration service was further categorized as successful or failed. RESULTS: Of 155 SSCs, 137 were considered successfully functioning. Total failures were 18. The overall combined success rate for the study group was observed to be 88% with an average service period of 45.18 months. Significant success was noted in patients less than 9 years of age, and significant failure was observed in patients 12 years and older. CONCLUSIONS: Stainless steel crowns are a viable option for interim restoration needs, with an 88% overall success rate during an average service period of 45.18 months.

Complete-mouth rehabilitation using a 3D printing technique and the CAD/CAM double scanning method: A clinical report.

According to evolving computer-aided design/computer-aided manufacturing (CAD/CAM) technology, ceramic materials such as zirconia can be used to create fixed dental prostheses for partial removable dental prostheses. Since 3D printing technology was introduced a few years ago, dental applications of this technique have gradually increased. This clinical report presents a complete-mouth rehabilitation using 3D printing and the CAD/CAM double-scanning method.

Uso de resina bisacrílica en la resolución estética en adolescente: caso clínico / The use of bisacrylic resin for the esthetic resolution in an adolescent: report of a clinical case

La estética constituye uno de los motivos de consulta de urgencia más frecuentes durante la adolescencia. Recientemente, fueron introducidos en el mercado, productos a base de resinas bisacrílicas. Tienen como componente principal metacrilatos multifuncionales con relleno de vidrio y/o sílice que constituyen la principal diferencia con los acrílicos convencionales. El objetivo de este trabajo es presentar un caso clínico de un paciente de 10 años de edad, resuelto en la Cátedra de Odontología Integral Niños de la Facultad de Odontología, Universidad de Buenos Aires, utilizando para la confección de restauraciones dentales temporales, una resina bisacrílica autopolimerizable.

Aesthetics is one of the most frequent reasons for urgent consultation during adolescence. Recently, products based on bisacrylic resins have been introduced on the market. They have as main component multifunctional methacrylates with filling of glass and / or silica that constitute the main difference with conventional acrylics. The objective of this work is to present a clinical case of a 10-year-old patient, resolved in the Chair of Integral Dentistry of the Faculty of Dentistry, University of Buenos Aires, using for the preparation of temporary dental restorations a bisacrylic resin self-cured.

The use of incinerated pig head in dental identification simulation.

PURPOSE: The aim of this exercise was to simulate a disaster victim identification scenario to allow training in documentation of postmortem incinerated remains and reconciliation of dental data. METHOD: Varying number of restorations were placed in ten pig heads. The teeth and restorations were charted, with the restorations radiographed and documented, creating an ante-mortem data set. The following day the heads were cremated. Following cooling and recording they were transported for a post-mortem examination by trained specialist odontologists who were not involved in the initial antemortem phase. Recordings included the charting of teeth, restorations, lost teeth, and radiographs to simulate a post-mortem examination. A reconciliation of postmortem to antemortem information was attempted. RESULTS: There was an unacceptable amount of error in the postmortem examination of the heads. The errors related mainly to avulsed teeth and incorrect opinion of which charted surfaces the restorations were placed upon. Also noted were a considerable number of root fractures occurring beneath the crestal bone. This observation does not mimic the evidence observed in human incinerated teeth where the crowns tend to fracture off the roots at the dentin-enamel junction. CONCLUSION: The use of incinerated pig (Sus Scrofa) heads is not an ideal model for forensic odontology training in disaster victim identification. Differences in both anatomy and behavior following exposure to heat were shown to hamper documentation and subsequent comparison to antemortem data.

Intrusion of supraerupted maxillary molar using a high interim restoration on the defective opposing tooth: a clinical report.

Wear, extraction, or fracture of all or part of a mandibular first molar can lead to the supraeruption of the opposing maxillary molar, resulting in occlusal interference and lack of restoration space. This report describes a method to gain sufficient vertical space for permanent restoration. A direct composite resin restoration was placed on the occlusal surface of a lower molar, intentionally making the interim restoration high and intruding the maxillary molar. After 6 weeks, the extruded tooth returned to the desired position, and functional occlusion was restored, enabling a ceramic restoration on the mandibular molar. No marked adverse sensory reaction was reported in this therapeutic process, and no deleterious signs were detected in the teeth, periodontium, or temporomandibular joints. The simple treatment type was effective, noninvasive, and time saving, while also preserving maximum tooth structures.

Essix restoration: a novel approach for transitional teeth replacement.

Loss of teeth is a distressing situation. The patient may cultivate feeling of loss of an organ on loss of teeth. Especially when anterior teeth are lost appearance of the patient is compromised with altered pronunciation. This is a really embarrassing situation for people working as news readers, social workers, marketing executives, theatre artists or persons whose presentation in front of people is important as part of their work. Replacement of missing teeth immediately after loss is not possible always due to local and systemic physiological factors, age, pathological factors and unfavourable condition of soft tissue in a particular area. Various means are available for transitional replacement of teeth which may or may not require adjacent teeth preparation. Essix restoration is easy to fabricate and use the restoration option with great aesthetic value.

CAD/CAM-based polymer provisionals as treatment adjuncts.

The role and function of provisional restorations has changed significantly in recent years. The reasons include the improvement of material properties and the CAD/CAM production option using polymer blanks, which are offered by various manufacturers. Besides their classic indications in crown and bridge prosthodontics, provisional restorations are now used for soft-tissue management, preparation and adaptation in complex restorations that include changes in vertical relations, and as mock-ups in esthetic dentistry.

Treatment concept with CAD/CAM-fabricated high-density polymer temporary restorations.

Tooth wear in younger patients is perceived worldwide as an increasing problem. Its etiology is multifactorial (erosion, abrasion, attrition), and its treatment is challenging for the dental practitioner specifically when a great loss of the vertical dimension of occlusion has occurred. The aim of this article is to present a treatment approach for complex cases with high loss of tooth structure using computer-aided design/computer-aided manufacturing (CAD/CAM)-fabricated temporary high-density polymer restorations without any preparations. New manufacturing technologies and innovative materials such as high-density polymers offer good possibilities for restorations during the pretreatment period. This is especially important in circumstances requiring massive corrections of color, form, or position. Pretreatment periods are indispensable in refining important factors such as lip-position dynamics as well as the correct position of the smile line, which cannot be adequately assessed in the dental laboratory. In the presented case report, CAD/CAM-fabricated non-preparation restorations were adhesively placed on the worn dentition without any further loss of tooth structure. Such an approach provides the opportunity to "test-drive" the new restoration design in terms of function, phonetics, and esthetics, thus improving the predictability of the definitive restorations design. If any change in the design is required, it can be cost-effectively achieved through simple modification or replacement of the restorations.

Peri-implant hard tissue response to glow-discharged abutments: prospective study. Preliminary radiological results.

In the literature has been demonstrated that when an implant is placed in the oral environment, changes in peri-implant hard tissue level may occur. Several clinical procedures have been advocated to clinically minimize this bone resorption. However, minimal attention was paid to the soft- and hard-tissue abutment interaction. The present clinical preliminary study is intended to radiologically analyze the effect of glow-discharged abutments on hard tissue level changes after 18 months of prosthetic loading. Five patients needing an implant supported restoration in the anterior maxillary area with thin gingival tissue biotype and healed bone were recruited. An implant was inserted and a titanium abutment was glow-discharged with an Argon plasma treatment in a plasma reactor and, immediately after, definitively screwed at 30N. Provisional restoration was therefore positioned. Three months later, definitive restoration was performed. Digital periapical standardized radiographs were taken at the time of surgery, 6 and 18 months thereafter. Radiographic analysis was carried out using image analysis software. At baseline, interproximal radiographs revealed no bone defect around implants in both groups. After 6 months from baseline, the postoperative interproximal radiographs revealed an average bone loss of 0.09mm (range 0.0-0.3mm, SD=0.144mm). After 18 months from baseline, the periapical X-ray showed a stable condition of bone remodeling (mean value: 0.09, range 0.0-0.5mm, SD=0.08mm). Within the limit of this study, glow-discharged abutments have been demonstrated to positively affect hard tissue reaction to implant restoration.

Acrylic resin polymerization in direct contact to the abutment and the temperature at bone-implant interface: a pilot in vitro study.

Three autopolymerizing acrylic resins were applied to a titanium alloy abutment connected to 2 different diameters of an implant. The implants were embedded in fresh iliac bone of sheep in a 37°C water bath. Temperature changes were recorded via embedded thermocouples at the cervical (T1) and apical (T2) regions of the implant surface. Polymerization temperature of acrylic resins did not seem to exceed the critical threshold of 47°C.

Biomechanical behavior of restored and unrestored mandible with shortened dental arch under vertical loading condition.

The aim of this in vitro study was to investigate the strain distribution of the compressed mandible bone under the applied restoration- removable partial denture and to compare with the same but unrestored mandible under vertical (occlusal) load and to find out whether removable partial denture-restored or unrestored mandible causes greater strain effect on supporting tissue. Four mandible models were tested during loading for the purpose of strain measuring. Digital image correlation system (GOM - German Optical Measuring, Braunschweig, Germany), used for measuring strain consists of two digital cameras and software ARAMIS (6.2.0, Braunschweig, Germany). Remaining teeth suffer from greater strain in the mandible model without removable partial denture (7.5-10%). On the contrary, mandible with removable partial denture shows the maximum strain below the denture saddle (3.5%). However, it can be noticed that the marginal bone of the second lower praemolar in both experimental models is deformed whether the mandible model has (2.8%) or has not (10%) replacement. Within the limitations of this study the higher strain is observed in mandible model without replacement and the strain is limited locally, in the bone region that surrounds remaining teeth and mental foramen.

Effect of implant abutment modification on the extrusion of excess cement at the crown-abutment margin for cement-retained implant restorations.

PURPOSE: To compare the effect of implant abutment modification on the amount of cement extruded at the crown-abutment margin and to evaluate the vertical discrepancy after cementation. MATERIALS AND METHODS: Access openings of titanium abutments were modified with an opening (open) and placement of two vent holes 3 mm from the occlusal edge and 180 degrees apart (internal vent). Access openings were filled with resin material (closed) and used as controls. Each abutment was secured to an implant analog. Eugenol-free zinc oxide cement (TempBond NE) was selected to cement the cast crowns (n = 9) onto test abutments. The amount of cement extruded out of the margin was calculated, and vertical seating discrepancies were determined with a linear transducer device before and after cementation. Differences among groups were analyzed statistically. RESULTS: The mean amount of extruded cement ranged from 36% to 90% of the total cement placed within the crowns. The order, from least to greatest amount of excess cement extrusion at the margins, was internal vent, open, and closed; significant differences were observed between test groups. The net vertical discrepancies of tested specimens ranged from -7 µm to +6 µm (mean, 0 µm). No statistically significant differences in vertical discrepancy were found between the groups. CONCLUSIONS: Venting the hollow abutment resulted in the least amount of cement extrusion when compared to closing off the screw access channel or leaving it open. Within the limitations of this study, it may be concluded that the use of two, 0.75-mm radius vent holes placed 3 mm apical to the occlusal area of the abutment and 180 degrees apart will limit the amount of cement extruded into the gingival sulcus of implant-retained crowns.

[Application of valplast dentures in the temporary restoration of single missing anterior tooth].

OBJECTIVE: To evaluate the value of valplast dentures in the temporary restoration of single missing anterior tooth. METHODS: Totally 76 patients who needed temporary restoration of single missing anterior tooth were involved and equally divided into two groups according to their own choices of procedures: group A, with valplast dentures as their temporary dentures and group B, with conventional removable partial dentures as their temporary dentures. Meanwhile,38 patients who had their single anterior teeth pulled out and did not need temporary dentures were enrolled as control group without any temporary restoration, and impressions were taken immediately before the temporary dentures were used (2 weeks after tooth extraction) and before the initiation of permanent restorations (97-100 days after tooth extraction).The heights of clinical crowns of the adjacent teeth were also recorded twice from plaster models made from the impressions.The height of labial gingiva recession was calculated as the difference between the two heights recorded. RESULTS: The height differences of clinical crowns of the adjacent teeth was 0.5mm (range: 0.0-1.2mm) in group A, which was significantly larger than those in group B [0.0mm;(range: 0.0-0.6mm)](P<0.05) and in group C[0.0mm;(range: 0.0-0.4mm)](P<0.05).However, the difference was not significant between group B and group C (P>0.05). CONCLUSION: Application of valplast denture as temporary denture may cause labial gingival recession of the adjacent teeth, and therefore is not suitable for the restoration of single missing anterior tooth.

Immediate restoration with ti-unite implants: practice-based evidence compared with animal study outcomes.

PURPOSE: Clinicians often do not have the benefit of adequate safety or clinical data when evaluating the merit of either newly marketed implant devices or novel clinical procedures. This has been the case for dental implants following the initial documentation of their safety and efficacy and is demonstrated in the evolution of immediate load application. Following demonstration of safety and successful application of an implant in an animal study prior to its market release, this report provides the clinical outcomes for the first 100 Ti-Unite implants provided to 24 patients in a clinical practice over 9 years. MATERIALS AND METHODS: An electronic record/clinical database review of consecutive early loaded implants from a multiple surgeon/single prosthodontist practice was conducted for quality assurance. Data extraction of standard exposure and outcome variables was accomplished by a trained individual not affiliated with the clinical practice. RESULTS: The results revealed one failure before and none following definitive restoration with a variety of prostheses. The mean length of time from immediate to definitive restorations was 5.3 ± 1.1 months for crowns, 3.9 ± 1.3 months for fixed partial dentures, and 7.8 ± 4.1 months for mandibular "hybrid" prostheses. The most common unexpected findings during the initial three postinsertion visits were lost access restoration and cement failure. CONCLUSIONS: Pre-market animal data regarding the safety and success of a new implant used with an early loading protocol was replicated in the clinical results of the first 100 implants used in practice. Additionally, the clinical results are favorable when compared to conventional loading protocols from this same practice and provide helpful comparative metrics (delayed vs immediate loading) to use when discussing implant treatment with patients.

Retention force of secondary crowns to copings after temporary cementation: the effect of crown material and luting agent.

Tooth-implant supported restorations can be temporarily cemented if the natural abutments are protected by permanently cemented copings. This in vitro study investigated the retention forces of pure titanium crowns to milled titanium alloy copings and of cobalt-chromium crowns to copings made of electroplated gold after cementation with different luting agents. Five specimens per group were cemented with acrylic-urethane cement (inner crown surface preisolated with petroleum jelly) and provisional zinc oxide cement. The retention was measured using a universal testing machine and a dental device for crown removal. The differences between groups were compared using analysis of variance. The pull-off forces for the cobalt-chromium secondary crowns cemented on gold copings using zinc oxide cement were significantly higher (mean=144.5 N) than the other crown-cement combinations (32.2-54.4 N), which showed no significant differences in the retention force. The impulse number and magnitude of the dental device was usually low and showed no substantial differences between the crown-cement combinations. It can be concluded that the results of the clinical removal method for prostheses differ from the results of the pull-off test. The question which luting agent is the better choice for retrievable restorations remains unanswered without further clinical and laboratory studies.