Abutment Teeth Research Articles

Ocena szczelności brzeżnej i dopasowania koron wykonanych z różnych materiałów w technologii CAD/CAM

Ocena szczelności brzeżnej i dopasowania koron wykonanych z różnych materiałów w technologii CAD/CAM

Alternative Conservative Approach for Tooth Build-Up in Patients with Special Healthcare Needs

Purpose: The success of an artificial crown mainly depends on the biomechanical factors such as bonding capacity of cement between the crown and abutment tooth, and root strength of the abutment tooth. In this case series, we aim to provide insight on the potential use of the cast metal post and cost for patients with intellectual disabilities and severely compromised tooth structure. Material and Methods: The first patient was a 41-year old male with the chief complaint of a dislodged porcelain fused metal (PFM) crown of tooth #20 (mandibular left second bicuspid). The patient was informed about the advantages, disadvantages, and risks of each option. After further consideration and discussion with the parents and the patient, we decided to rebuild the coronal tooth structure with the cast metal post and core and prosthetic restoration with the same crown. Patient satisfaction was measured on the visual analog scale as 10/10. The second case involves a 26-year old female, who presented with a chief complaint of chronic lingering pain on tooth #9. The tooth structure was extensively damaged and un-supportive of the ferrule, therefore, it was decided to build a metal post and core instead of a fiber post. The prosthetic restoration was made with a monolithic zirconia crown and the patient was followed up twice in 6 months and graded the satisfaction as 10/10 on a visual analog scale. Results: The most common type of posts used in dentistry has been cast post and cores in the last decade which generally includes an additional laboratory stage where a custom post is prepared according to the impression taken from the prepared post space. Conclusions: Both the presented cases explain an interesting advantage of restoring a root canal treated tooth with a metal post and core system which implies that in a prefabricated post and core restored tooth failure, a metal post, and core can potentially be the treatment of choice instead of extracting the tooth.

Direct bonded fixed partial denture with an artificial denture tooth as a pontic.

BackgroundThe present review aimed to investigate the feasibility and clinical effectiveness of a direct bonded fixed partial denture (DBFPD) based on available literature. The efficiency of a DBFPD is mainly affected by the type of artificial denture tooth, the type of luting agent, and the adhesive preparation.MethodsThe parameters were reviewed based on the in vitro and in vivo studies conducted. An acrylic resin tooth or a composite resin tooth for removable dentures should be used as the artificial tooth for the pontic.ResultsConsidering the luting agent, a methyl methacrylate-based resin luting agent, which has low mechanical strength but is capable of plastic deformation and could sustain for a long time, should be used. Appropriate pre-adhesive treatment should be performed on both the artificial and abutment teeth. The cases in which a DBFPD can be applied are limited to one missing anterior tooth, as long as it is not overstressed. Patient cooperation in cases of occlusion seems to be another prerequisite.ConclusionKnowledge and selection of the material and case indications are essential, and patient cooperation is pertinent in studying the long-term prognosis of a DBFPD.

Clinical Evaluation of the Effect of Implant-Supported and Implant Retained Distal Extension Removable Partial Dentures on the Supporting Structures

Objective: To evaluate and compare the effect of implant supported versus implant retained removable partial denture restoring Kennedy's class I cases on the supporting structures by measuring modified gingival index and probing depth for abutment teeth and implants.
 Subjects and Methods: Twelve patients; who had Kennedy class I mandibular partially edentulous ridge extending distal to the first or second premolar, were selected from the outpatient clinic, Prosthodontics Department, Faculty of Dentistry, Minia University. The patients were classified into two equal groups; according to the implant superstructures either dome shaped abutment or ball and socket attachment. Each Patient of both groups had two implants in second molar position (one in each side) and received removable partial denture of the same design. Patients were followed up for one year clinically. Group I: Six patients received RPD supported by dome shaped short abutments. Group II six patients received RPD retained by ball and socket attachments.
 Results: Results revealed that, there was no statistically significant difference between the two groups regarding modified gingival index and probing depth around the abutment teeth and implant abutment.
 Conclusion: The use of dome shaped abutment or ball and O-ring attachment have the same effect on gingival index and probing depth around natural abutments and implants in Kennedy class I mandibular situations.

Early failures when using three different adhesively retained core build-up materials\u2014a randomized controlled trial

ObjectivesTo compare the failure rates for three different adhesively retained core build-up composites up to the incorporation of a permanent fixed dental prosthesis (FDP), and to identify potential failure risk factors.Material and methodsA randomized controlled trial of 300 participants in need of a core build-up to restore a vital abutment tooth before prosthetic treatment was conducted. Participants were assigned by stratified block randomization to one of three study groups: Rebilda DC (RDC), Clearfil DC Core (CDC), or Multicore Flow (MF). Test teeth were prepared by use of the respective manufacturer’s adhesive system. The total-etch technique was used for RDC and MF, and the self-etch technique for CDC. Participants were treated by dentists (n = 150) or dental students (n = 150). Failure rates of core build-ups before incorporation of FDPs were investigated using univariate and multiple logistic regression.ResultsThe overall failure rate was 8% (n = 23). Rate differences between the three investigated groups did not reach statistical significance (p > 0.05). The mean time between placement of core build-ups and placement of fixed dental prostheses was 12.2 (SD: 14.2) weeks. Conversely, larger cavities (> 3 surfaces) and treatment by dental students were independently associated with an increased failure risk (p < 0.05).ConclusionsThe main risk factors for early failure seem to be the size of the core build-up and clinical experience of the operator, whereas failure rates of core build-up materials combined with a self-etch approach seem to be similar to the rates of materials combined with the total-etch technique.Clinical significanceThis research article should give clinicians an impression of the short-term performance of different adhesively retained core build-ups using different adhesive techniques/materials. Moreover, predominant influencing factors for the success or failure should be pictured.

A straightforward protocol for designing an interim hollow shell with open-source software

BackgroundAn interim hollow shell (IHS) is a temporary prosthesis that adapts like a cap over a prepared tooth abutment. Using a conventional protocol to fabricate IHS from casts of the initial situation or the wax-up can be challenging, time-consuming, and sometimes frustrating. A digital workflow makes this process quicker and more convenient. The IHS must be first designed with computer-aided design (CAD), then fabricated with computer-aided manufacture (CAM). Proprietary dental software is commonly used for the design process but needs to be purchased. ObjectiveTo describe a step-by-step technique for designing an IHS for posterior relining with open-source software. MethodsThis paper describes a straightforward procedure to design an IHS from a dental scan of the initial situation or a digital wax-up for an esthetic and functional temporary rehabilitation. ResultsAn IHS can be quickly designed using open-source software by copying an existing restoration or a conventional or digital wax-up. Then, the design can be 3D printed using a biocompatible resin. ConclusionsThe clinician can use open-source software to design IHSs, which are then 3D printed using a biocompatible resin. Clinical relevanceThe clinician can design IHSs from a dental scan of the initial situation or a wax-up using open-source software by following the step-by-step protocol outlined in this paper. The restoration can then be 3D printed using a biocompatible resin.

Influence of the Connector Area on the Chipping Rate of the VM9 Veneering Ceramic in a Posterior Four-Unit Yttria-Stabilized Tetragonal Zirconia Polycrystal Fixed Dental Prostheses: A Pilot Study

Abstract Objective The purpose of this study was to evaluate the influence of the connector area on the chipping rate of the VM9 veneering ceramic in a 4-unit yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) framework, using a novel sonographic technique. Materials and Methods The framework was designed as a 4-unit fixed dental prostheses (FDP) with two abutment teeth at the first mandibular premolar and second mandibular molar. The cross-sectional area of the connector was 7.5, 8, or 9 mm2. The prepared teeth were scanned using CAD/CAM technology, and five frameworks were prepared for each design, making a total of 15. The frameworks were divided according to the veneering ceramics: Y-TZP FDPs using Vita VM9 (12 frameworks), and porcelain fused to metal (PFM) FDPs using Vita VM13 (3 frameworks). The specimens were statically loaded until failure. To capture the initiation of the failure within the specimens, a novel sonographic technique, designed for this research, combining acoustic emission and visual monitoring during live load bearing tests, was used to determine the failure load value. Failed frameworks were inspected using a microscope, and failure patterns were identified. One-way ANOVA and Tukey HSD tests were applied for statistical analysis of the results (p-value ≤ 0.05). Results Despite the fact that the chipping strength is proportional to the cross-sectional area of the connector, the effect of the cross-sectional area on chipping load revealed no statistically significant differences, while PFMs showed superior chipping strength relative to the zirconia frameworks regardless of the connector's size. A high rate of catastrophic fracture occurred while loading the specimens. Conclusion The effect of the cross-sectional area on chipping load revealed no statistically significant differences in Y-TZP frameworks. The novel sonographic technique may be a potential method to study the behavior of dental ceramics, including chipping and fracture.

Treatment planning considerations in the older adult with periodontal disease.

Periodontal health in the elderly is influenced by numerous factors, including systemic conditions, patient compliance, age-associated changes, and restorative procedures. The numerous comorbidities seen in the elderly necessitate individualized approaches for treatment planning. In this paper, we review how age, comorbidities, oral hygiene, and restorative dental procedures collectively influence the treatment and management of the periodontium in the elderly. The elderly population is predicted to double in 30years, which will have an economic impact the dental profession needs to plan for. Preventative and noninvasive treatment, supportive periodontal therapy, and patient-specific maintenance plans are imperative to maintaining oral health in the older population. Multiple coexisting changes, including xerostomia, altered wound healing, altered bone physiology, altered microbiome, and diminished plaque control, can add complexity to periodontal management. Considerations of the patient's general health, the selected periodontal treatment plan, and the selected completed restorative procedures need to be considered. The influence of caries, fixed prosthodontics, partial dentures, shortened dental arch, and implant therapy can have unintended impacts on periodontal health in the elderly. Adverse periodontal outcomes in the elderly can be minimized by carefully assessing the patient's medical history, impact of medications, functional needs, properly finishing and contouring restorations to avoid plaque accumulation, and designing restorations to allow access for hygiene. Partial dentures can be a source of plaque accumulation leading to periodontal disease, caries, and recession around abutment teeth. A shortened dental arch should be considered as a functional and cost-effective alternative to partial dentures. With dental implants, the patient's tissue phenotype, keratinized tissue quantity, risk of peri-implantitis, and patient access for maintaining adequate oral hygiene are all important to consider. Implant risk-assessment tools show promise by providing a systematic approach for early diagnosis to avoid future complications.

Method of preparation "along the axis" of teeth that serve as a support for extended orthopedic structures

A common mistake of an orthopedic dentist when carrying out odontopreparation of teeth is nonobservance of the parameters of the permissible convergence of the axial walls of the teeth [1]. Analysis of the literature allows us to conclude that with the taper of the tooth walls at 15 degrees, the retention of the crowns is 70 % [2]. The aim of this work was the development of an improved method for coaxial odontopreparation of teeth. This article describes the method of odontopedication of teeth, which are a support for fixed orthopedic structures of an extended nature. The essence of the method is to create a bed on the abutment teeth using a thin fissure bur. The process of coaxial preparation of abutment teeth in the author's technique consists of several stages, which makes it possible to control the preparation accuracy and qualitatively reduce the likelihood of excessive grinding of tooth tissues.

Analysis of the relationship between the surface topography of prepared tooth surfaces and data quality of digital impressions from an intraoral scanner

Background/purposeWith the rise of digitalization in dentistry, intraoral scanners and digital impressions have recently been adopted by many clinicians. The aim of this study was to investigate surface topography of prepared teeth and the accuracy of digital impressions. Materials and methodsTwenty mandibular typodonts, containing left first premolar and left first molar abutment teeth manufactured by using CAD/CAM, were used in this study. An intraoral scanner was used to scan each typodont, and each STL file generated was exported in high resolution (Group H), moderate resolution (Group M), and low resolution (Group L). All 60 files were inspected in a 3-D mesh processing software. For each file, the number of triangulation points in the meshwork were obtained for both abutment teeth. ResultsThe measurements obtained from the 3-D mesh processing software revealed that the mean number of triangulation points on the 3-D surface of the abutment teeth (20 premolars + 20 M) were 790,625 ± 98,890 dots in Group H, 592,283 ± 74,881 dots in Group M, and 198,067 ± 19,328 dots in Group L. Significant differences were found between Group H and M (p < 0.05), Group H and L (p < 0.001), and Group M and L (p < 0.01). ConclusionThe outcomes of this study reveal that there are strong correlations between the data quality of digital impressions and surface topography of prepared teeth. Therefore, the utilization of STL files in high resolution format is the recommended choice for clinicians engaging in a digital workflow process.

Comparison of marginal and internal fit of three-unit implant-supported fixed prosthetic substructures fabricated using CAD/CAM systems.

This study compared the marginal and internal fit of implant-supported fixed dentures fabricated using CAD/CAM systems. A lower jaw model representing partial edentulism was produced. Two dental implants were inserted in the area of teeth 35 and 37, onto which cemented abutments were screwed. The model was scanned using a laboratory scanner and transferred to a design software program for substructure fabrication. Sixty substructures were fabricated out of each group for six substructure types (n = 10), cast Co-Cr (control), milling Co-Cr, laser sintering Co-Cr, titanium (Ti), zirconium, and polyetheretherketone (PEEK) substructures. The marginal and internal fit was evaluated using a silicone replica viewed under a stereomicroscope. The data were analyzed using the statistical package program for social sciences (SPSS, Chicago, IL, USA, v. 17) at a significance level of 0.05. Marginal and internal gaps were compared using the one-way ANOVA test and Tukey's post hoc test. The differences between abutment teeth were determined using the independent sample t-test. There was a significant difference in the marginal gap between PEEK and Ti groups (p <0.05) but no difference between other groups (p >0.05). There was a significant difference in the internal gap between PEEK, laser sintering Co-Cr, and milling Co-Cr groups (p< 0.05) but no difference between other groups (p> 0.05). The PEEK group had a higher marginal gap than the Ti group and a higher internal gap than the DMLS Co-Cr group (p< 0.05). All substructures have a marginal and internal fit within acceptable clinical limits. This in vitro study suggests that materials and techniques used in CAD/CAM systems improve the fitting accuracy of implant-supported fixed restorations.

Evaluation of marginal adaptation of CAD/CAM vs conventional all-ceramic crowns on an implant abutment: An in vitro study

The survival of fixed prosthodontic restorations depends on the state of the marginal adaptation. Marginal gaps can create a favourable condition for biofilm deposition, thereby contributing to the development of caries and periodontal disease. The longevity of fixed prosthodontic restorations depends on the condition of the marginal adaptation to the abutment teeth. The presented work aimed to study, evaluate and compare the marginal adaptation of All-Ceramic crowns fabricated using conventional laboratory procedures with those fabricated using the CAD/CAM technology.To compare the marginal fit and adaptation of All- Ceramic crowns obtained by conventional techniques and crowns obtained by CAD/CAM technique. The presented study focused on a total of 20 samples divided into two groups viz. Group I (Conventional) and Group II (CAD/CAM) having 10 sample each. The samples were prepared with the straight abutment having a standardized collar height of 2mm, HIOSSEN that was mounted on acrylic blocks using implant analogue, HIOSSEN. A set of crowns was produced by 5-axis milling lithium disilicate using glass-ceramic blocks with laboratory fabrication methods. Another set of zirconia crowns was produced using CAD/CAM technology. Circumferential marginal gap measurements were taken at 12 measurement locations on the hexagonal die marked equidistant to each other. Both the samples were measured for marginal discrepancy at under the stereomicroscope.The results obtained showed that the mean vertical gap for the group II samples showed the least variation in the marginal discrepancy. Although the mean obtained for both the groups showed that the mean vertical marginal discrepancy was within the clinically acceptable level.It can be concluded that within the limitation of the study the data obtained showed that The Mean vertical gap was the maximum for Group I (Conventional group) i.e. 49.25 µm showing maximum variation in marginal fit. While the CAD/CAM Group had shown least vertical marginal discrepancy which depicts statistically significant better marginal fit than those fabricated using conventional laboratory procedures.

Stress distribution and patient satisfaction in flexible and cast metal removable partial dentures: Finite element analysis and randomized pilot study

PurposeTo compare stress distribution in polyacetyl based flexible RPD (FRPD) with cast metal RPD (CRPD) by using three-dimensional finite element analysis (FEA) and patient satisfaction by using OHIP-14 questionnaire in participants with Kennedy's class I partially edentulous mandibular arch rehabilitated with CRPD and FRPD. Material and methodsFor FEA, 3D models of Kennedy's class I partially edentulous mandibular arch, CRPD in chrome-cobolt alloy, and polyacetyl based FRPD were geometrically modelled and subjected to a vertical load of 100 ​N bilaterally. The in vivo comparison of satisfaction was assessed by enrolling 22 participants with Kennedy's class I partially edentulous mandibular arch. After randomization, 11 participants were rehabilitated by CRPD (group C), and 11 participants by polyacetyl based FRPD (group F). OHIP-14 questionnaire in Hindi language was filled at 1 week and 1 year after denture insertion. ResultsVon Mises stress distribution in CRPD was maximum in mesial rest seat of the primary abutment (100 ​MPa) and minimum for edentulous ridge (7 ​MPa on bone and 6 ​MPa on mucosa). Von Mises stress distribution for polyaccetyl based FRPD was maximum in ridge (25 ​MPa) and minimum in periodontal ligament of the second premolar (3 ​MPa). Patient satisfaction in group F was significantly more than in group C at end of 1 year (P ​= ​.0158). ConclusionFRPD is useful in periodontally compromised abutment teeth and CRPD in resorbed ridge conditions. Patient satisfaction is more with polyacetyl based flexible RPD when compared with cast metal RPD at the end of 1 year.

THE EFFECT OF AGING ON SURFACE ROUGHNESS OF PROVISIONAL CROWN AND BRIDGE MATERIAL

Background: Provisional dental restoration fabricated to enhance esthetic, stabilization of abutment teeth and maintain function for limited period of time after which it is to be replaced by definitive fixed restoration. The surface roughness of temporary crowns are considered crucial in achieving successful definite restorations. Most bacteria in the oral cavity can only survive on hard and rough surfaces. The objective of the present study is to evaluate and compare the surface roughness of two types of commercially available composite material (Harvard- temp and Charm- temp). The specimens were tested in dry conditions and after two weeks of storage in artificial saliva at 25⁰C. Material and Methods: A total of 32 specimens of dimensions 64mm×10mm×2.5mm were divided in two groups according to the type of material (Harvard-temp or Charm-temp). Each group of material has 16 specimens. These 16 specimens were divided in two groups: a control group (eight specimens) in dry conditions and an aging group (eight specimens) and stored in artificial saliva for two weeks. The TR 200 device was used to measure the surface roughness of specimens in micrometers (µm) before and after aging in artificial saliva. Results: After comparing the results, a significant difference was found in the surface roughness in dry and aging conditions of Harvard – temp (P&lt;0.05). However, there is a non-significant effect noticed for the dry and aging condition of Charm-temp groups (P&gt;0.05). Conclusion: that in-vitro aging research might be an informative predictor of provisional materials’ properties before clinical application. Clinical significance: Both materials can perform adequately in the oral cavity for two weeks. However, the Charm temp mayperform more adequately and maintain good surface roughness.

ПЕРСПЕКТИВЫ ИЗГОТОВЛЕНИЯ КАРКАСОВ МЕТАЛЛОКЕРАМИЧЕСКИХ КОНСТРУКЦИЙ ЗУБНЫХ ПРОТЕЗОВ МЕТОДОМ СЕЛЕКТИВНОГО ЛАЗЕРНОГО СПЕКАНИЯ

The article presents the results of evaluating the prototyping of metal-ceramic structures made by casting and selective laser sintering. To achieve this goal, 27 patients with fabricated metal-ceramic crowns and bridgeworks were examined. Two study groups were created. The first group included 14 patients for whom dental prosthesis frameworks were made by casting. The second group consisted of 13 people, for whom the frames of dentures were made by the method of selective laser sintering. The analysis of clinical effectiveness was carried out according to the following criteria: 1- precision of the felling of prosthesis frame to solid tissues of abutment teeth; 2- the condition of the marginal periodontium; 3- the integrity of the ceramic cladding. The results of the study showed that the precision to solid tooth tissues of metal-ceramic dental prostheses made by laser selective sintering is higher than of frames made by casting. In accordance to the second criteria the best results were also shown by the participants of the second group. No chipping of the ceramic veneer from the metal-ceramic denture frameworks made by laser selective sintering was found. Thus, dentures which frameworks are made by the method of selective laser sintering are characterized by a higher objective assessment of their precision to the solid tissues of the abutment teeth. Lesions of the marginal periodontium both inflammatory and dystrophic were less in the participants of the second group. The frequency of defects in the coating of metal-ceramic dentures was significantly lower in the case of fabrication frameworks by laser selective sintering.

Problems of dental preservation and complex therapy of chronic generalized periodontitis

Epidemiological studies have reported the prevalence of inflammatory periodontal diseases of 85%90% in individuals aged 30 years. Predicting the possibility of preserving teeth is an important integral part of treatment planning for periodontitis. Traditionally, the prognosis is based on the likelihood of tooth loss. The article presents a review of the literature characterizing the factors that affect the prognosis of the service life of teeth in case of periodontitis. For the literature review, a literature search was performed on the MedLine, EMBASE, CyberLeninka, and eLibrary databases. The following factors should be considered when assessing the long-term prognosis in patients with the highest risk for tooth loss: severity of periodontitis, smoking, bruxism, number of abutment teeth, age, type of tooth, depth of probing the periodontal pocket, bone loss, furcation involvement, root mobility and proportions, and tooth crowns. Indicators for molar loss include furcation lesion, bone loss progression, endodontic treatment, persistent periodontal pocket, age, female sex, smoking, and diabetes mellitus. A favorable treatment result and preservation of teeth depend on the entire group of teeth, with the following values: 85% in single-rooted anterior teeth, 78% in premolars, and 47% in molars. The low accuracy of standard predictive tooth loss indices can be explained by the point that the indices are mainly based on factors related to teeth and do not take into account the influence of patient-related factors. Thus, predicting the service life of teeth with periodontitis is a difficult task and requires taking into account both individual indicators of periodontal status and general factors.

Retrofitting of an implant-supported surveyed crown under an existing removable partial denture by using an acrylic resin template

Retrofitting a crown to an existing removable partial denture (RPD) is a complex process and requires additional clinical and laboratory procedures. Various methods have been described for retrofitting a new tooth-supported crown. However, if an abutment tooth has to be extracted, descriptions of techniques for restoring a new edentulous site with an implant-supported crown retrofitted to an existing RPD are lacking. Therefore, this technical report describes a straightforward approach to fabricating an implant-supported surveyed crown fitted to an existing RPD by using an acrylic resin template.

MICROBIOLOGICAL ASPECTS OF APPLYING CLINICAL DIAGNOSTIC COMPLEX OF ORTHODONTIC METHODS FOR RESTORING DESTROYED CORONAL PART OF TEETH

Improving the quality of restoration of the destroyed coronal part of the teeth by orthopaedic methods has led to significant scientific and clinical interest and has been discussed in numerous reports, but the issues on reparative regeneration and restoration of the gingival margin relief in the area of ​​the anterior group of teeth after reconstructive orthodontic measures in the case of restoration of destroyed tooth crowns and deep subgingival carious destruction have not been sufficiently studied yet. The purpose of this study was to investigate the microbiological peculiarities of applying a clinical diagnostic complex of manipulations designed to restore anterior teeth with cast posts to provide the grounds for long-term favourable outcomes of further orthopaedic treatment in order to obtain aesthetic appearance, taking into account the state of the surrounding soft tissues. To carry out high-quality preparation of periodontal tissues around the abutment tooth, patients underwent gingivectomy using a scalpel with a disposable blade, diode laser electrocoagulation and coagulation. The effectiveness of each method of the preparation of the marginal gingiva was evaluated by the findings of clinical and microbiological studies. We have found out all three tested methods of forming a new gum relief in the root area of ​​a preserved tooth can significantly improve the qualitative and quantitative composition of the microflora in the stump area. A significant decrease in the frequency of biotope colonization by pathogenic and transient microorganisms and the improvement of the species composition in the local oral microbiocenosis can be achieved by cutting the hypertrophied epithelial edge of the cervical area with a microsurgical scalpel and using laser coagulation. Clinical and microbiological studies have confirmed the effectiveness of the clinical diagnostic complex of techniques for preparing the marginal gum around the root of the tooth, which is planned for orthodontic treatment with a post and an inlay. The use of a diode laser has been found to show the highest efficiency compared to other presented methods. All of the above techniques can be used in dental practice as methods of choice.

Clinical outcomes of tooth-supported leucite-reinforced glass-ceramic crowns after a follow-up time of 13–15 years

ObjectivesThe aim of this retrospective clinical study was to investigate the survival rate, technical and biologic complications of leucite-reinforced glass-ceramic crowns after a follow-up time of 13–15 years. Material and methodsFifty-three patients with 131 crowns were invited to the follow-up visit. The reconstructions were re-examined clinically and radiographically using the modified USPHS criteria and periodontal parameters of probing pocket depth (PPD), plaque index (PI), sulcus bleeding index (SBI). Patient satisfaction and post-operative sensitivity of the abutment teeth were evaluated with a questionnaire. The overall survival rate and the Kaplan-Meier survival estimate were calculated both on crown and patient level. Technical and biological complications were reported descriptively on crown level. The p-value <0.05 was considered statistically significant. ResultsThirty-eight patients (12 men, 26 women) with 93 crowns were examined. The overall survival rate of all the crowns was 79.6% after a mean observation period of 14.4 ± 1.2 years. Most of the failures occurred after 11.1 years. The most common clinical failures were inacceptable ceramic fractures or chippings, which occurred in 5 out of 93 crowns (5.4%) and periodontitis, seen in 4 out of 93 teeth (4.3%). The most frequent technical complications were related to occlusal wear. Biological complications were not common. ConclusionsLeucite-reinforced glass-ceramic crowns showed a high survival rate of 79.6% after an observation period of 13–15 years. Ceramic fractures and periodontitis accounted for the majority of clinical failures. Clinical significanceLeucite-reinforced glass-ceramic crowns can be considered a safe and predictable treatment choice for restoring both anterior and posterior teeth.

Removable partial denture metal framework manufactured by selective laser melting technology – A clinical report

The selective laser melting technology is an additive digital method that permits producing metal frameworks for removable partial dentures. The existing literature has compared this technique with the classic technique in terms of precision, quality of fit, and function. This work describes a clinical case of a metal framework produced by the selective laser melting technique in a patient rehabilitated with a removable partial denture. No adjustments were required when the metal framework was inserted, showing good adaptation and stability to the abutment teeth and surrounding tissues. Further studies are necessary for a significant assessment of this technique’s clinical applicability.