Provisional Restoration Research Articles

Fracture strength of 3-units fixed partial dentures fabricated with metal-ceramic, graphene doped PMMA and PMMA before and after ageing: An in-vitro study

ObjectivesTo evaluate the fracture strength and linear elongation at break of three-units fixed partial dentures (FPDs) fabricated with traditional and new materials for fixed prosthodontics before and after ageing. MethodsSixty models of three-units FPDs were fabricated and cemented onto a Co-Cr model simulating the replacement of a maxillary second premolar. The samples were randomly divided into 3 groups: metal-ceramic (MCR), graphene-doped polymethylmethacrylate (PMMA-GR) and polymethylmethacrylate (PMMA). Half of the samples were directly subjected to fracture test, while the remaining half underwent an ageing process and then a fracture loading test using an electrodynamic testing machine. Fracture load and elongation at break values were taken and statistically analysed. ResultsSignificant differences were detected between the different materials (p<0.05). All groups showed a reduction of the fracture load and elongation at break values after ageing, but not statistically significant, except for PMMA group (p = 2.012e-19) (p = 3.8e-11). ConclusionsMCR and PMMA-GR three-units FPDs showed higher fracture strength and lower elongation at break compared to PMMA. MCR and PMMA-GR had higher resistance to ageing processes compared to PMMA. Clinical significancePMMA-GR could be considered a material for long-term provisional restorations as its mechanical behaviour and ageing resistance are more like MCR than PMMA.

A Comparative Analysis of Bacterial Adhesion on Different Long-Term Provisional Fixed Prostheses Fabricated by CAD/CAM Milling, 3D Printing, and Heat Cure Technique: An In Vivo Study

ABSTRACT Objectives: This study compares the bacterial susceptibility to three different provisional restorations manufactured with different laboratory techniques, i.e., heat cure, CAD/CAM, and 3D printing Materials and Methods: Totally, 45 health patients with age group of 30–60 years undergoing complete veneer crown treatment were selected for the study and divided into three groups with 15 samples in each as Group I: the crowns were made from polymethyl methacrylate polymer fabricated by the conventional heat cure method, Group 2: the crowns were made from polymethyl methacrylate fabricated by subtractive manufacturing CAD/CAM method, and Group 3: the crowns were made from oligomers fabricated by additive manufacturing 3D printing. The samples were examined for bacterial adherence at scanning electron microscope. The colony-forming units (CFUs) were calculated, and statistically analyzed. Results: It has been determined that the digitally fabricated provisional restorations prove to be superior in terms of surface topography than to the conventionally fabricated provisional restorations Conclusion: The study concludes that 3D-printed provisional restorations are more precise with reduced bacterial susceptibility than milled ones.

Fit and Strength of a Three-Unit Temporary Prosthesis Made by Different Manufacturing Techniques: An In Vitro Study.

To compare the fit and fracture load of temporary fixed partial prostheses fabricated by means of a conventional direct technique, milling, or 3D printing. A maxillary right first premolar and molar were prepared on a Frasaco cast, which was then duplicated 40 times. In total, 10 provisional three-unit fixed prostheses (Protemp 4, 3M) were made using the conventional technique with a putty mold. The 30 remaining casts were scanned to design a provisional restoration using CAD software. A total of 10 designs were milled (CEREC MC X5/shaded PMMA Disk, Dentsply Sirona), while the other 20 were 3D printed with one of the two 3D printers (Asiga UV MAX or Nextdent 5100, C&B, Nextdent). Internal and marginal fit were examined using the replica technique. Next, the restorations were cemented on their respective casts and loaded until fracture using a universal testing machine. The location and propagation of the fracture were also evaluated. 3D printing demonstrated the best internal fit. Nextdent (median internal fit: 132 μm) was significantly better compared to the milled (median internal fit: 185 μm; P = .006) and conventional restorations (median internal fit: 215 μm; P < .001), while the fit of Asiga (median internal fit: 152 μm) was only significantly better than the conventional restorations (P < .012). The lowest marginal discrepancy was found for the milled restorations (median marginal fit: 96 μm), but this was only significant when compared to the conventional group (median internal fit: 163 μm; P < .001). The conventional restorations demonstrated the lowest fracture load (median fracture load: 536 N), which was only significant when compared to Asiga (median fracture load: 892 N; P = .003). Within the present in vitro study's limitations, CAD/CAM demonstrated superior fit and strength compared to the conventional technique.

Timing implant provisionalization: Decision-making and systematic workflow.

Provisionalization is an important step to achieve esthetic results in implant cases, and many different techniques for provisional restoration fabrication have been described. However, depending on the clinical scenario, the provisionalization strategy will require different approaches and timing. The clinician should modify the provisional restorations efficiently to reduce the number of disconnections from the implant, as repeated disconnections may have biological consequences. This article aims to schematize different scenarios requiring implant provisionalization and propose strategies to help the clinician condition the peri-implant tissues, respecting perio-prosthodontic fundamentals for soft tissue, biological, and esthetic stability. The clinical outcomes of modern implant therapy aim to achieve results that emulate natural dentition. Different scenarios may require adjunct therapy, including hard- and soft-tissue grafting, which complicates treatment. The provisionalization strategy will vary depending on the initial condition of the tissues, the need for reconstructive procedures, and the timing of implant placement. Selecting the right strategy based on the case type is necessary to reduce treatment time and complications associated with inadequate prosthetic handling of the soft tissues. Proper emergence profile conditioning through provisional restorations will allow for biologically sound and esthetically pleasing outcomes in implant restorations.

Which caries removal method to select?

Searches were carried out using PubMed/MEDLINE and Web of Science databases between January 2008 and January 2023. Only articles in English language were included. Boolean operators were used to search: "permanent teeth" OR "permanent tooth" OR "permanent dentition" AND "deep caries" OR "stepwise" AND "partial caries removal OR "stepwise caries removal" OR "pulp vitality" OR "healing rate". Inclusion criteria were randomised controlled trials, which compared the total removal of carious tissue with either a selective or stepwise removal in permanent teeth with deep carious lesions. Criteria also required a follow up of at least 6 months and publications in English. Exclusion criteria were articles in other languages, articles not comparing different types of total or selective caries removal and articles published before January 2008. Data extraction followed PRISMA guidelines. Two reviewers independently screened articles, analysing titles and abstracts using Rayyan's Intelligent Systematic Review Platform. They also collected data and risk of bias assessed using the Cochrane Risk of Bias Tool for Randomised Trials, dividing articles into high risk of bias, few concerns and low risk of bias. A third researcher resolved conflict or doubt in case of divided opinions. In total, 105 articles were identified, and 10 duplicates removed. 95 articles were reviewed by title and abstract and 75 of these did not meet the inclusion criteria. 20 articles were then read, excluding a further 15 due to comparing only partial removal or non-selective caries removal or absence of numerical data. This left 5 articles which met eligibility criteria. These were randomised controlled trials between 2010 and 2021. Follow up ranged from 1 month to 5 years. The inclusion and exclusion criteria in all studies had similar clinical parameters. 3 studies performed management only on permanent molars, whilst the rest also included management on permanent incisors/canines/premolars and molars. Management of caries was divided into non-selective caries removal vs partial caries removal (either selective or stepwise). All but 2 studies included specific information about the materials used. Liners were calcium hydroxide or Dycal, provisional restorations were glass ionomer cements or Ketax Molar and definitive restorations were Herculite Tetric N-Ceram resin, Ivolclar Vivadent or amalgam. Clinical success or failure was measured using pulp vitality, absence of periapical lesions, radiographic analysis and lack of symptoms. Clinical follow up was evaluated by external examiners, although 2 studies did not specify this clearly. There were a variety of tools used for statistical analysis in each study. When comparing non-selective caries removal with either selective or stepwise, 3 studies proposed statistically significant differences in terms of longevity, marginal integrity and success rate of restorations. 1 study stated inexistence of statistically relevant divergences between procedures. Non-selective caries removal is not highly recommended for deep carious lesions and may be considered invasive and risks pulpal exposure. Both selective and stepwise removal are considered conservative approaches. Selective removal is considered the best management option in the short term (with 1.5 years follow up), predominantly related to a lower risk of pulpal exposure. At 5 years, however, the results of selective were similar to those of non-selective, accepting the null hypothesis. There were also no differences in success rates for materials used for definitive restorations.

Expedited Provisionalization of a Missing Crown: A Case Report.

Provisional restorations are required in fixed prosthodontics to protect a prepared tooth until a definitive restoration can be delivered. A patient sought treatment at a prosthodontics practice to replace a missing provisional crown until definitive treatment could be performed once the patient returned from a field exercise. This case report describes a novel way to provide a provisional restoration when other techniques are not feasible, which can be utilized in the clinic or in an austere environment.

Comparison of Fracture Resistance between Implant-supported Bis-acryl Interim 3-unit FDPs Using Six Different Strengthening Mechanisms: An In Vitro Study.

To investigate six different strengthening mechanisms for three-unit implant-supported provisional restorations. Six techniques of provisional fixed prostheses (PFP) reinforcement were investigated and were assigned to different groups (n = 10): group (ZP) zirconia powder, group (SK8) silk thread wrapped as a figure-of-8 pattern around middle third of abutment, group (RC8) size 00 retraction cord wrapped as a figure-of-8 pattern around middle third of abutment, group (RF8) Resin impregnated glass fiber ribbon wrapped as a figure-of-8 pattern around abutment, group (KV8) Kevlar 29 cord wrapped as a figure-of-8 pattern around middle third of abutment, group (KV) Kevlar 29 strands incorporated in resin mix. Compared against unenforced bis-acryl as control group (CL). Seventy Metal Dies were 3D printed having Soft Tissue Gingiva Mask. Using a custom-made silicone Index, 70 PFP were fabricated (10 of each group) and were cemented to their corresponding metal dies using zinc polycarboxylate cement. All specimens were thermal cycled for 1000 cycles using order of 20 seconds at 55°C and 20 seconds at 5°C with 10 seconds transport. Fracture resistance test was done using universal testing machine. All specimens were loaded to failure. Data were collected, tabulated and statistically analyzed. Kolmogorov-Smirnov normality test showed no significant difference between data in each group. So, data are normally distributed in each group. Descriptive statistics showed higher mean values of CL group (780.8 ± 164) followed by RF8 group (614.2 ± 158.2), followed by RC8 group (550.2 ± 339.2), followed by KV8 group (442.1 ± 198.4), followed by KV group (403.9 ± 306), followed by SK8 group (175.9 ± 90.8), and finally ZP group (136.5 ± 135.7). One-way ANOVA revealed significant difference between the tested groups (p = 0.036). Bis-acryl provisional restorations had better mean fracture resistance values than all other strengthening mechanisms. Bis-acryl provisional restorations did not gain more strength by any of the added materials. One-way ANOVA revealed significant difference between all tested groups. Provisional restorations over implant should be strong enough to serve for the long period of bone and tissue healing. Current materials alone cannot survive for long. It serves as temporization between steps of fixed restorations construction. How to cite this article: Rayyan M, Sayed M, Hujeiry AM et al. Comparison of Fracture Resistance between Implant-supported Bis-acryl Interim 3-unit FDPs Using Six Different Strengthening Mechanisms: An In Vitro Study. J Contemp Dent Pract 2023;24(11):840-846.

The flexural strength of 3D-printed provisional restorations fabricated with different resins: a systematic review and meta-analysis

BackgroundThree-dimensional (3D) printing technology has revolutionized dentistry, particularly in fabricating provisional restorations. This systematic review and meta-analysis aimed to thoroughly evaluate the flexural strength of provisional restorations produced using 3D printing while considering the impact of different resin materials.MethodsA systematic search was conducted across major databases (ScienceDirect, PubMed, Web of Sciences, Google Scholar, and Scopus) to identify relevant studies published to date. The inclusion criteria included studies evaluating the flexural strength of 3D-printed provisional restorations using different resins. Data extraction and quality assessment were performed using the CONSORT scale, and a meta-analysis was conducted using RevMan 5.4 to pool results.ResultsOf the 1914 initially identified research articles, only 13, published between January 2016 and November 2023, were included after screening. Notably, Digital Light Processing (DLP) has emerged as the predominant 3D printing technique, while stereolithography (SLA), Fused Deposition Modeling (FDM), and mono-liquid crystal displays (LCD) have also been recognized. Various printed resins have been utilized in different techniques, including acrylic, composite resins, and methacrylate oligomer-based materials. Regarding flexural strength, polymerization played a pivotal role for resins used in 3D or conventional/milled resins, revealing significant variations in the study. For instance, SLA-3D and DLP Acrylate photopolymers displayed distinct strengths, along with DLP bisacrylic, milled PMMA, and conventional PMMA. The subsequent meta-analysis indicated a significant difference in flexure strength, with a pooled Mean Difference (MD) of − 1.25 (95% CI − 16.98 - 14.47; P < 0.00001) and a high I2 value of 99%, highlighting substantial heterogeneity among the studies.ConclusionsThis study provides a comprehensive overview of the flexural strength of 3D-printed provisional restorations fabricated using different resins. However, further research is recommended to explore additional factors influencing flexural strength and refine the recommendations for enhancing the performance of 3D-printed provisional restorations in clinical applications.

Digital superimposition of scans for recording and transferring vertical relation from provisional restorations when rehabilitating worn-out dentition: A dental technique.

Excessive wear of the natural dentition results in the loss of tooth anatomy and the vertical dimension of occlusion (VDO) which may necessitate full mouth rehabilitation. Successful full-mouth rehabilitation with increased VDO requires accurate recording and transfer of the newly raised VDO with provisional restorations. Conventional bite registration can incur errors during the recording and transfer of vertical dimensions. This article introduces a digital approach-the superimposition of scans using an intraoral scanner (IOS) to transfer VDO, occlusion, and aesthetic data from provisional restorations for designing and fabricating indirect restorations in the management of worn-out dentition.

Effect of build orientation on the fracture resistance and marginal quality of 3D-printed anatomic provisional crowns: An in-vitro study

IntroductionComputer-aided design and computer-aided manufacturing (CAD/CAM) technologies have been increasingly used to fabricate provisional restorations in recent years. This study assessed how build orientation influences the fracture resistance and marginal quality of 3D-printed crowns compared with milled provisional crowns. MethodsThe test group included 3D-printed crowns (Freeprint temp Shade A2, Detax, Ettlingen, Germany), which were further subdivided based on print orientation (0°, 45°, and 90°; n = 10 for each subgroup). The control group (n = 10) included milled crowns (Coratemp, White Peaks, Germany) with the same design as those of the test group. The margin quality of each crown was assessed at 60 × magnification using a digital stereomicroscope. A load-to-fracture test was performed by applying a force at a rate of 2 mm/min to assess fracture resistance. One sample from each subgroup was also subjected to scanning electron microscope (SEM) analysis. ResultsThe milled group exhibited the highest fracture resistance and marginal quality. Within the printed subgroups, the 0° group showed the best mean marginal quality, whereas the 90° group showed the lowest mean marginal quality (p < 0.05). Within the test groups, the 90° group had the highest mean fracture resistance (p < 0.05). In the SEM analysis, the milled group exhibited the most homogenous boundaries, whereas among the 3D-printed subgroups, the samples printed at 0° had the best margin quality. ConclusionThe manufacturing method significantly influences the marginal quality and fracture resistance. Milled crowns demonstrated superior marginal quality and fracture resistance compared to those of 3D printed crowns. Furthermore, the print orientation of 0° led to the best marginal quality, whereas printing at 90° led to the highest fracture resistance.

Experience of oral rehabilitators on the techniques and materials used in temporary restorations

Provisional restorations are temporary dental interventions that protect the tooth from thermal and chemical changes, in addition to restoring its anatomy and aesthetic functionality for a short period. These are performed with different techniques and materials, selected according to the patient's clinical situation and the dentist's criteria. Using a qualitative descriptive approach, a structured interview with open questions was conducted with 10 oral rehabilitators, using intentional non-probabilistic sampling. It was found that provisional restorations should provide a good seal, isolate the preparation from the buccal environment, and be comfortable and esthetic. The materials used must be easy to clean, resistant, bioactive, and promote dental remineralization, supporting occlusal loads and thermal changes to guarantee pulp protection and occlusal functions. Its proper use ensures the quality of the final restoration and allows effective oral hygiene. The materials are selected by the dentist according to the patient's needs, such as their economic situation and the condition of the tooth, and the experience with provisional restorations has been positive, allowing quality results. To avoid complications, a temporary that is easy to handle is required, which guarantees a good seal and facilitates cleaning

Posterior single implants immediately loaded using one abutment at one time and temporary abutment in the posterior mandible without bone augmentation: A report on six-month outcomes data obtained from a prospective randomized controlled split-mouth clinical trial

Background/Aim. Given that frequent manipulation of the abutment during immediate loading can have a negative impact on the surrounding peri-implant hard and soft tissues, the concept ?one abutment at one time? (OAO) has been introduced and documented in daily clinical practice. The aim of the study was to evaluate changes in peri-implant bone levels, clinical and radiographic parameters, and patient perspectives during the six-month follow-up period. Methods. The study was designed as a randomized controlled clinical trial. Patients with bilaterally healed sites in the posterior mandible received implants with a diameter of no less than 3.5 mm and a length of at least 8 mm. Based on randomization, patients were divided into a test group and a control group. Patients who were in the test group received implants that were immediately loaded with definitive abutments. In contrast, patients in the control group received implants where healing abutments were placed, followed by temporary abutments. Implants were immediately loaded with provisional restorations within the first seven days. They were delivered over the test group?s definitive abutment and the control group?s temporary abutment. Probing depth, bleeding on probing, clinical attachment level, plaque index, and keratinized tissue width were measured. Patient-Reported Outcome Measures and the Oral Health Impact Profile - 19 (OHIP-19) questionnaires were noted. Results. Out of 24 included patients, 22 completed the six-month follow-up. Peri-implant bone loss between study groups was comparable (mesial: t = -0.798, df = 21, p = 0.434; distal: t = 1.688, df = 21, p = 0.106), without statistical inter-group significance. OHIP-19 total scores significantly decreased after three months and remained similar six months after the implant placement in both groups without statistically relevant clinical inter-group changes. Conclusion. The OAO approach and provisional abutments showed comparable effectiveness regarding the immediate loading of posterior single implants.

Finishing and polishing systems influence the roughness and color stability of acrylic and bis-acryl composite resins.

To evaluate the effect of different finishing and polishing systems on the surface roughness and color changes of bis-acryl (Protemp 4 - 3M ESPE- St. Paul, USA; Structur 3 - Voco, Cuxhaven, Germany) and chemically activated acrylic materials (Duralay - Reliance, SP, Brazil). Specimens (10 x 2 mm) thick were prepared for each material. The specimens were subjected to polishing and finishing procedures with aluminum oxide discs (Diamond Master - FGM, Joinville, Santa Catarina, Brazil) and spiral rubber disks (Sof-Lex - 3M ESPE, Germany). The control did not receive any polishing and finishing procedures. Surface roughness and color measurement values were obtained after the finishing and polishing procedures and immediately after 30 days of storage in water, coffee, and red wine. Data for each material were analyzed by One-Way ANOVA (p<0.05). The polishing with aluminum oxide discs was able to affect the initial surface roughness values of chemically activated acrylic material (p<0.05). After immersion in staining solutions, lower ∆E values were only observed for the bis-acryl composite resins compared to the control group (p<0.05). The finishing and polishing systems influenced the surface roughness and color stability of the materials tested. The chemically activated acrylic resin showed lower surface roughness and higher color stability than the bis-acryl materials. Key words:Acrylic resin, bis-acryl resin, provisional restoration.

Early complications and quality of life in patients with immediately loaded implant-supported maxillary partial rehabilitations: A prospective cohort study.

Immediate loading of dental implants is considered an excellent option to reestablish function and aesthetics in a short period of time, thereby reducing the psychological impact of edentulism. The aim of this study was to describe the incidence of complications in immediately loaded implant-supported single or partial maxillary provisional rehabilitations; to assess changes in patient quality of life (QoL); to evaluate patient overall satisfaction; and to determine whether the occurrence of complications affects these outcomes. Patients requiring partial rehabilitation with implants in the maxilla were included in a prospective cohort study. In all cases, implant-based restoration with an immediate loading protocol was indicated. A provisional restoration was placed within 72 hours after implant placement. Patient QoL was measured at the first appointment and just before placing the final restoration, using two validated questionnaires. All mechanical and biological complications occurring up until placement of the final restoration were documented. A descriptive and bivariate analysis of the data was performed. Thirty-five patients with 40 prostheses supported by 60 implants were analyzed. Three implant failures were observed, yielding a 95% survival rate. Five provisional prosthesis fractures and two prosthetic screw loosenings were recorded in four patients. A significant reduction in OHIP-14 score was observed. Likewise, significant differences were found in the results of the QoLFAST-10, with a mean difference in score of 7.3 between the initial and final evaluation. Patients receiving immediately loaded implant-supported single or partial maxillary provisional rehabilitations seem to have a low risk of developing early mechanical (13.3%) or biological complications (5%). These patients appear to experience significant improvement in QoL and report excellent overall satisfaction with the treatment received - though the occurrence of complications seems to affect these outcomes.

Evaluation of immediate dental implant with socket sealing by a provisional restoration

Evaluation of immediate dental implant with socket sealing by a provisional restoration

Impact of dental operative microscopes on precision in minimally invasive dental restoration procedures.

To evaluate the effect of dental operative microscopes on precision in minimally invasive dental restoration procedures. This retrospective analysis included patients who underwent minimally invasive dental restoration procedure at Nanjing Stomatological Hospital from March 2018 to December 2019. Patients were categorized into two groups, an observation group treated with microscope-guided provisional restorations, and a control group treated using conventional methods. Clinical indices, including implant survival rates over five years, were compared between the groups. Multivariate analysis was employed to identify independent risk factors for implant failure. After treatment the observation group exhibited significantly lower labial vertical marginal discrepancies and absolute marginal discrepancies, as well as improved labial gingival indices and periodontal probing depths compared to the control group (all P<0.001). Additionally, the observation group scored significantly higher in efficiency, accuracy, and overall quality of tooth preparation (all P<0.001). Clinicians using microscopes demonstrated significantly lower mean Rapid Upper Limb Assessment scores, indicating reduced ergonomic strain (P<0.001). Higher age, worn tooth defects, poor oral hygiene, and non-use of a microscope were identified as independent risk factors for implant failure at the five-year mark. Dental operative microscopes significantly enhance the precision, efficiency, and ergonomic comfort in minimally invasive dental restorations for both clinicians and patients. Widespread adoption of this technology is strongly recommended.

Immediate and Long-Term Pull-Out Bond Strength of 3D-Printed Provisional Crowns.

Background: Over the past decade, 3D printing technology has revolutionized various fields, including dentistry. Provisional restorations play a crucial role in prosthetic rehabilitation, necessitating the evaluation of their bond strength with different provisional cement agents. Aims: This study is aimed at assessing the immediate and long-term bond strength of 3D-printed dental crowns using three provisional cement agents. Materials and Methods: Provisional crowns (N = 36) were manufactured using 3D modeling software and cemented in dentin analogues (G10 Nema resin). After the crowns' fabrication, they were randomly divided into three groups (n = 12) for cementation with Relyx Temp 3M ESPE, Provicol-VOCO, and Meron-VOCO. Tensile strength tests were conducted using a universal testing machine, with half of the specimens subjected to 2000 thermal cycles before testing. Finite element analysis was employed to assess tensile stress distribution. Results: Statistical analysis (two-way ANOVA and Tukey's test at a 95% confidence level) revealed significant effects of cement type (p = 0.006) and thermal aging (p = 0.001) on bond strength. Glass ionomer cement exhibited the highest immediate resistance, while all types of cement were adversely affected by thermal aging, resulting in decreased bond strength. Conclusion: Thermal aging significantly alters the properties of 3D printing resin and affects the bond strength of provisional cement with 3D-printed crowns. Despite the adverse effects of thermal aging, glass ionomer cement demonstrated the highest immediate resistance. Clinicians should carefully consider these findings when selecting provisional cements for 3D-printed crowns.

Influence of fabrication method on the marginal fit of temporary restorations.

Computer-aided manufacturing (CAM) technology allows the use of different manufacturing techniques. This in vitro study aimed to evaluate the marginal fit of temporary restorations manufactured using conventional chairside methods, milling, and three-dimensional printing. Fifteen 3-element temporary restorations specimens were produced and categorized into three groups: non-digital, obtained using the conventional chairside method (GC); milled (GM); and three-dimensionally printed (GP). Marginal fit was assessed using scanning electron microscopy (SEM) performed under two conditions: one with only the central screw tightened, and the other with all three screws tightened. Horizontal misfit values were categorized as over-, equal-, and under-extended and qualitatively analyzed. Statistical analysis was performed using the Tukey-Kramer test (α=0.05). In the vertical assessment, three-dimensionally printed restorations demonstrated greater misfit than restorations obtained by milling and the conventional chairside method (P<0.05). In the horizontal assessment, the misfit in the GP group was significantly higher than that in the GM and GC groups. Restorations obtained using the conventional chairside method and milled provisional restorations showed more favorable results than three-dimensionally printed restorations.

Comparison of the effect of zirconia and titanium abutments on peri-implant hard and soft tissues.

The primary objective of this research was to assess and compare the impact of customized zirconia (Zr) and titanium (Ti) abutments, placed on early loaded dental implants, on both hard tissue (as measured crestal bone level) and soft tissue (as assessed by sulcular bleeding index [SBI], probing depth [PD], and Pink Esthetic Score [PES]), through clinical and radiographic evaluation. This research involved a sample of 15 patients who had partially dentulous mandibular arch. Within this group, a total of 30 implants were surgically placed. Specifically, each patient received two implants in the posterior region of the mandible, and the bone density in this area was classified as D2 type. In each patient, one implant was loaded with Zr abutment and the other was loaded with Ti abutment. The bone quality in the area of implant placement was Type D2. Two groups were created for this research. Each group consisted of 15 early loaded dental implants with customized Zr abutments and customized Ti abutments respectively. Hard- and soft-tissue changes were evaluated in both the groups. Evaluation of crestal bone loss (CBL) with cone beam computed tomography and SBI, PD and PESs were evaluated by various indices at 2, 4, and 6 months postloading. After obtaining the readings, data were subjected to statistical analysis and comparison of quantitative data was done, paired t-test was used. The mean CBL in the Ti abutment is higher; the difference between the two groups was not statistically significant. SBI and PD for Zr were higher, but there was no statistically significant difference between the two groups. Zr had a higher PES than Ti abutment and the difference between the two groups was statistically significant. In the literature till date, the PES of Zr abutments were proven better for provisional restorations in implant prosthesis, but very few literatures support the same for the final implant restorations. The study did not reveal a clear advantage of either Ti or Zr abutments over the other. Nevertheless, Zr abutments tended to produce a more favorable color response in the peri-implant mucosa and led to superior esthetic outcomes as measured by the PES.

Staged esthetic crown lengthening: Classification and guidelines for periodontal-restorative therapy.

This article presents technical guidelines for perio-restorative esthetic crown lengthening, along with a discussion of the biologic rationale. A classification system is proposed to assist in treatment planning and sequencing the surgical and restorative phases. When esthetic crown lengthening is performed as an adjunct to restorative therapy, the surgical approach must be determined by the anticipated position of the restorative margins. The removal of sufficient bone to achieve the desired clinical crown length and preserve the supracrestal gingival tissue dimensions is facilitated by the use of a surgical guide fabricated according to the design of the restorations. A staged approach allows sequencing the provisional restoration to minimize unesthetic sequelae during the healing period. Inadequate bone resection and/or alteration of the soft tissue dimensions results in delayed healing, leading to coronal gingival rebound and biologic width impingement. The identification and preservation of appropriate restorative and biologic landmarks is essential for success in pre-prosthetic esthetic crown lengthening treatment. A staged approach improves the esthetic management during the postsurgical healing and maturation period. A restorative driven classification system for sequencing and staging adjunctive esthetic crown lengthening procedures is presented. Technical guidelines to enhance gingival margin predictability are suggested, accompanied by relevant evidence. In addition, wound healing timelines following gingival and osseous resection are provided.