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The commonly used materials for fixed restorations in edentulous jaws include acrylic resins, polymerized ceramics, ceramics, and zirconia, which have distinct physicochemical properties and clinical application features. The selection of these materials in clinical practice is related to the prosthodontic space, oral soft and hard tissue conditions, occlusal force, lifestyle habits, oral parafunctions, opposing dentition materials, and expectations of patients. Common mechanical complications associated with fixed restorations in edentulous jaws are cracking/chipping and abrasion of the facing materials, which can be avoided through occlusal adjustment, restoration design and processing, and the selection of appropriate restorative materials. This article reviews the characteristics, selection, and design considerations of commonly used materials for fixed restorations in edentulous jaws, as well as the causes and management of common clinical complications related to restorative materials, aiming to provide references for the selection of appropriate materials in fixed restorations for edentulous jaws in clinical practice.

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Background/purpose: Retainer debonding of resin-bonded fixed dental prostheses (RBFDPs) is one of the major reasons for their lower survival rates than fixed dental prostheses (FDPs) with full-coverage crowns. Recent advances in milling technology have enabled the fabrication of RBFDPs with complex retainers (D-shaped designs). This study aimed to assess the marginal fit and retention force of zirconia RBFDPs with inlay-, L-, and D-shaped designs to clarify their clinical applications. Materials and methods: Three abutment teeth models without maxillary second premolars were created using inlay-, L-, and D-shaped retainer designs. The zirconia RBFDPs were designed and fabricated according to the manufacturer's instructions (n = 10). The marginal gap was measured using the silicone replica technique. Zirconia frameworks were bonded to the abutment teeth using resin cement. Tensile test was conducted after thermal cycling and dynamic loading tests. The loads during debonding or fracture were recorded. The failure pattern was analyzed by observing the fracture surface using a scanning electron microscope. Results: D-shaped RBFDPs showed a significantly larger marginal gap than inlay- and L-shaped RBFDPs (P < 0.05). However, the mean marginal values were clinically acceptable (<120 µm). The D-shaped model exhibited the highest tensile strength in the tensile tests. The inlay-shaped and most of the D-shaped RBFDPs experienced debonding with cohesive failure, whereas the L-shaped RBFDPs showed fractures near the connector. Conclusion: The D-shaped retainer design was superior to the inlay- and L-shaped designs with respect to the inhibition of retainer debonding. However, the marginal fitness needs to be improved.

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OBJECTIVES: To evaluate three temporary luting cements in terms of their restoration loss rates, biological interactions, esthetic properties, and handling characteristics. MATERIALS AND METHODS: 75 adults requiring fixed prosthodontics voluntarily participated in a single-blind, randomized controlled trial. After preparation, temporary restorations were luted with a randomly selected temporary luting cement (either Provicol QM Plus (PQP), Bifix Temp (BT), or Provicol QM Aesthetic (PQA)). Clinical examinations were performed one to two weeks after cementation. The following criteria were evaluated: tooth vitality, percussion, hypersensitivity, gingival bleeding, odor formation, esthetics, cement handling, removability, cleanability, and retention loss. Antagonistic teeth served as controls. Statistical analysis was performed using the paired t-test, one-way ANOVA, Pearson's chi-square and Fisher's exact test, where appropriate. RESULTS: The overall loss rate of temporary restorations was 16.0%, showing no cement-specific differences. Postoperative hypersensitivity occurred in 8% of cases regardless of cement type. Esthetic impairment was reported by 31% of the PQP-fixed restorations, compared with 4.0% and 4.2% of the BT and PQA-bonded restorations. Cement application was reported to be easy in 100% of cases, excess removal in 88-96%, depending on the cement used. CONCLUSIONS: The choice of luting material affects the esthetic appearance of a temporary restoration and should be considered, particularly in restorations in esthetically demanding areas. No significant differences between the cements were identified regarding biocompatibility, handling, and loss rate. CLINICAL RELEVANCE: Translucent cements can help to reduce color interferences, resulting in a more appealing appearance of the temporary restoration.

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Background: Few studies have established the relationship between connector widths, cuspal angulation, loading forces, and supporting structures of zirconia fixed dental prosthesis (FDP). The objective of the study was to compare the stress distribution in implant- and tooth-supported zirconia FDP with different connector designs, and cuspal angulations of replaced teeth under diverse angulations of forces. Methods: Finite element (FE) analysis was done by simulating a 3-unit implant- and tooth-supported FDP. FE models with varying cuspal angulations 0°, 20°, and 33° and connector designs 2 mm, 2.5 mm, and 3 mm was generated. The simulated models were loaded with 100 N of forces under different axial and non-axial angulations. The graphical and numerical stresses were observed, recorded, and statistically analyzed. Results: Higher stress of 245.55 MPa in implant-supported FDP and lower stress value of 28.22 MPa in tooth-supported FDP was observed at 0-cuspal inclination for 3 mm connector width. The data were statistically analyzed with unpaired t test to eliminate the differences. The inter-group, intra-group tests, p and t values for various connector, and tooth angulations of tooth- and implant-supported FDP were statistically insignificant. (p > 0.05). Conclusion: There was no statistically significant difference in stress was observed between tooth- and implant-supported FDP for different connector widths, cuspal inclination, and diverse angulation of forces.

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OBJECTIVES: This study aimed to evaluate the effect of the clinical removal of fixed partial dentures on oral health-related quality of life and the anxiety values of individuals and to determine the clinical factors of high anxiety levels. METHOD AND MATERIALS: In total, 300 participants were included in the study. Six different reasons for the clinical removal of fixed partial dentures (oral examination, denture renewal, endodontic treatment, tooth extraction, periodontal treatment, and composite filling restoration) were defined. The United Kingdom Oral Health-Related Quality-of-Life Measure (OHRQoL-UK), the Modified Dental Anxiety Scale (MDAS), and the Spielberger State-Trait Anxiety Inventory- State (STAI-S) and Trait (STAI-T) were answered. The reason groups were compared using one-way analyses of variance. Binary logistic regression analyses were performed to evaluate the risk factors for high anxiety. RESULTS: There was no significant difference in OHRQoL-UK scores (P = .279) among the reason groups, but there were significant differences in MDAS, STAI-S, and STAI-T scores (P = .004, P .001, P = .018, respectively) among the reason groups. Endodontic treatment, tooth extraction, and sex were determined to be risk factors, considering the anxiety scales. CONCLUSIONS: Females are 2.2 times more likely to have trait anxiety than men. Although the effect of the reason for the clinical removal of fixed partial dentures on oral health-related quality of life was similar among the groups, it is concluded that endodontic treatment and tooth extraction reasons for the clinical removal of fixed partial dentures could be risk factors for high anxiety regardless of fixed partial denture usage time.

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OBJECTIVES: The aim of this in vitro study was to investigate whether and to what extent different scenarios of rotational freedom in different IAC designs affect the vertical dimension of a three-part fixed partial denture (FPD). At the same time, the experimental setup should simulate all clinical and laboratory steps of the implementation of such an FPD as accurately as possible. MATERIAL AND METHODS: Twenty identical pairs of jaw models were fabricated from aluminum, each lower-jaw model holding two implants with conical or flat IACs. Three impressions of each model were taken to fabricate stone casts and three-unit FPDs. Three assembly scenarios were compared for the vertical position stability they offered for these FPDs, differing by how the sequential implant components (impression posts > laboratory analogs > abutments 1 > abutments 2) were aligned with the positional index of the IAC. In this way, a total of 60 stone casts and FPDs were fabricated and statistically analyzed for changes in vertical dimension (p < 0.05). RESULTS: Regardless of whether a conical/flat IAC was used (p > 0.05), significantly greater mean changes in vertical dimension were consistently (all comparisons p < 0.0001) found in a "worst-case scenario" of component alignment alternating between the left- and right-limit stop of the positional index (0.286/0.350 mm) than in a "random scenario" of 10 dentists and 10 technicians with varying levels of experience freely selecting the alignment (0.003/0.014 mm) or in a "best-case scenario" of all components being aligned with the right-limit stop (-0.019/0.005 mm). CONCLUSIONS: The likelihood of integrating a superstructure correctly in terms of vertical dimension appears to vary considerably more with assembly strategies than with IAC designs. Specifically, our findings warrant a recommendation that all implant components should be aligned with the right-limit stop of the positioning index.

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OBJECTIVES: To evaluate the longevity of cantilevered zirconia-based resin-bonded fixed partial dentures (RBFPDs) in replacing missing posterior teeth, as well as the quality of life and patient satisfaction experienced by those receiving zirconia RBFPDs. METHODS: A prospective single-arm uncontrolled clinical trial was conducted to replace one or more missing premolars or molars with a span of 5 to 8 mm using cantilevered zirconia RBFPDs. Thirty-six participants with 40 prostheses were recruited and underwent a 3-year clinical evaluation. The retainer designs included a minimum thickness of 0.8 mm, a minimum of 200° circumferential wraparound with an occlusal bar, and a connector dimension of 3 × 3 mm. Patient-reported outcomes, including patient satisfaction and Oral Health Impact Profile (OHIP), were assessed. RESULTS: The average age of participants was 45.8 years, and 72.5 % were women. The success rate of the posterior zirconia RBFPDs was 76.2 %, with an estimated mean success duration of 46.1 months. The survival rate was 88.1 %, with an estimated mean survival duration of 49.4 months. Participants were highly satisfied with the treatment, achieving an average satisfaction score of 80.8 ± 11.9. Participants' total OHIP scores decreased from 52.3 to 39.6 after 3 years, indicating a significant improvement in oral health-related quality of life (P = 0.009). CONCLUSIONS: After 3 years, a moderately high survival rate and favourable patient-reported outcomes of posterior cantilevered zirconia RBFPDs were achieved. Therefore, it can be recommended as a conservative treatment option to replace missing posterior teeth, provided that retainer design considerations are taken into account. CLINICAL SIGNIFICANCE: Cantilevered zirconia RBFPDs for posterior teeth can serve as a conservative treatment option that is both aesthetically pleasing and biocompatible. It offers a more cost-effective alternative compared to dental implants, which are often prohibitively expensive for the majority of patients. This approach has the potential to greatly improve patient-reported outcomes.

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Effective treatment planning is crucial for implant-supported dental prostheses' success, requiring a thorough assessment of various factors, including bone quality, quantity, and available space. Evaluating space availability, encompassing height, width, and angulation, is imperative to ensure optimal implant positioning devoid of anatomical limitations. Adequate vertical space is essential for accommodating the implant-supported restoration while preserving proper occlusal function and esthetics. However, not all cases adhere to ideal standards, especially those featuring limited interocclusal space, as seen in scenarios of long-standing edentulous areas lacking prior prosthetic rehabilitation. Ideally, the interocclusal space should measure between 8-12 mm vertically. This case report details the management of reduced interocclusal space through the strategic placement of deeply positioned implants and the incorporation of a screw-retained fixed partial denture, effectively addressing the challenges associated with limited space.

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PURPOSE: To assess the accuracy of virtual articulation in direct digital workflow (DDW) and indirect digital workflow (IDW) in arches prepared for fixed partial dentures (FPDs). MATERIALS AND METHODS: Five pairs of master models were used in this study representing different clinical scenarios of full dentate (FD), and prepared arches for fixed partial dentures as follows: FD group, short span posterior (SSP group), long span posterior (LSP group), short span anterior (SSA group), and long span anterior (LSA). Fourteen pairs of interarch reference points were added to each set of master models to measure linear interarch distance with a caliper (reference measurements). The direct digital workflow included digital scans and virtual articulation with buccal scan images using an intraoral scanner. The indirect digital workflow included conventional polyvinylsiloxane impressions and bites followed by pouring, mounting, and scanning the stone models in a laboratory scanner. The scanned stone models were virtually articulated with buccal scanning in the laboratory scanner. Digital linear interarch measurements on all virtually-articulated models were compared with reference measurements. The absolute mean differences in linear interarch distances were calculated. The Mann-Whitney test was used for statistical analysis (α = .05). RESULTS: The direct digital workflow produced significantly less linear interarch deviations in the virtually articulated models compared to the indirect digital workflow for all study groups (P < .05). However, the direct digital workflow had significantly less accuracy for virtual articulation in long span posterior, long span anterior, and short span anterior groups compared to the full dentate group.  CONCLUSIONS: Both workflows produced virtually-articulated models with acceptable accuracy. However, the direct digital workflow had significantly better accuracy in all assessed clinical scenarios.

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Vertical dimension (VD) is a critical factor in prosthodontics, playing a pivotal role in the functional and aesthetic outcomes of dental treatments. This literature review explores theoretical foundations and the various aspects of VD, including its definition, measurement, and clinical significance in prosthodontics. The relationship between VD and temporomandibular disorders (TMDs) is examined. Additionally, the impact of VD on facial proportions and aesthetics is significant, as it affects the lower third of the face and influences the patient's overall appearance and self-esteem. In conclusion, understanding the intricate relationship between VD, TMDs, facial aesthetics, and psychological well-being is essential for effective prosthodontic treatment. This comprehensive review provides valuable insights into the multifaceted role of VD in enhancing both functional and aesthetic outcomes, ultimately improving patient satisfaction and quality of life.

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Despite the development of implant-supported prostheses, there are still patients for whom conservative treatments such as resin-bonded fixed dental prostheses (RBFDPs) are more appropriate. This study's objective was to analyze the available research on full-ceramic RBFDPs. In this study, Web of Science, MEDLINE/PubMed, Scopus, Embase, Cochrane Library, and Google Scholar databases were searched for articles published in English between 2010 and 2020. A total of 14 studies were reviewed based on the eligibility criteria. The results showed that using a cantilever design with one abutment had an advantage over two abutments. Additionally, it was proposed that preparations designed with retentive aids, such as a proximal box, groove, and pinhole, could improve RBFDP survival rates. IPS e.max ZirCAD, In-Ceram alumina, and zirconia CAD/CAM were the most commonly used framework materials. Most studies used air abrasion, salinization, or hydrofluoric acid for surface treatment. Adhesive resin cements were the most frequently used type of cement. The survival rate of In-Ceram ceramics (85.3%-94.8%) was lower than that of In-Ceram zirconia and IPS e.max ZirCAD. Debonding, followed by framework fracture, was the leading cause of failure. Following 3-10 years follow-up, the survival percentage of all-ceramic RBFDPs ranged from 76% to 100%. Although RBFDPs have demonstrated satisfactory success as a conservative treatment, long-term follow-ups and higher sample sizes in clinical research are required to gain more reliable outcomes on the clinical success rate of various RBFDP designs.

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PURPOSE: This study aimed to investigate whether the presence of a mesial cantilever influences the biomechanical behavior and screw loosening in fixed partial dentures (FPDs) with a distally tilted implant in the atrophic posterior maxilla and where to best place the distal implant. METHODS: Two configurations of implant-supported four-unit FPDs were modelled using finite element analysis. Five interabutment distances were considered. The stress and strain distributions in the implants, abutments, and prosthetic screws were verified under occlusal loading. The development of the axial force on the abutments and screws was also examined. Two-sample t-tests were used to identify differences (P < 0.05). RESULTS: The von Mises stress distributions of the components in the two configurations were similar, as were the maximum plastic strains of the distal prosthetic screws, distal implants, and 30° abutments. The difference in the maximum plastic strains of the straight abutments was statistically significant. The preload of the 30° abutment screws was significantly reduced after the initial loading. In the absence of a mesial cantilever, the axial force on the straight abutments increased. However, when a mesial cantilever was used, the preload of the straight abutments was maintained, and the axial force on the prosthetic screws fluctuated less. The axial force fluctuation of the abutments gradually decreased as the interabutment distance increased. CONCLUSIONS: Mesial cantilever usage had minimal effect on stress or strain distribution in FPD implants, abutments, or prostheses. However, it helped resist screw loosening. The distal screw access hole was preferably positioned close to the prosthetic end.

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OBJECTIVES: The objective of this review was to assess clinical trials that have examined the materials, design, and bonding of ceramic cantilevered resin-bonded fixed dental prostheses (RBFDPs) as a potential option for replacing missing anterior teeth. The evaluation primarily focuses on the rate of restoration failure and clinical complications. MATERIALS AND METHODS: A thorough search of databases including PubMed/MEDLINE, Scopus, and the Cochrane Library, was conducted. The most recent search was performed in October 2023. Clinical studies that compared ceramic cantilevered RBFDPs with double retainers or cantilevered RBFDPs using different ceramic materials or bonding systems were included. The outcome measures considered were restoration failure and complication rates. RESULTS: Twelve studies met the eligibility criteria. The pooled data showed a statistically significant decrease in complication events when using cantilever designs compared with double retainer designs (p < 0.05); however, there were no differences found between the two designs in terms of restoration failure. The complication and failure rate of cantilever RBFDPs did not show a statistically significant difference with or without ceramic primer application before luting with phosphate monomer-containing luting resin (p > 0.05). CONCLUSIONS: Ceramic cantilevered RBFDPs have lower complication rates compared with those with double retainers. The use of a ceramic primer prior to luting composite resin for ceramic cantilevered RBFDPs decreases the occurrence of complications and failures, although this effect was not statistically significant. Additional research is required to confirm these findings. Glass ceramic cantilever RBFDPs showed a decrease in success after 6 years, requiring ongoing monitoring, but both zirconia and glass-infiltrated alumina cantilever RBFDPs have demonstrated durability with excellent long-term success and survival rates for up to 10 and 15 years. CLINICAL SIGNIFICANCE: Cantilever ceramic RBFDPs in the anterior region are a less invasive and valuable treatment option, providing good esthetic results.

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PATIENTS: This case report presents a minimally invasive approach to replace a missing mandibular lateral incisor using a dual-injection molding technique with flowable composite resins. Integrated with a comprehensive digital workflow, this method achieves a structurally and esthetically biomimetic, bi-layered prosthetic solution. A 34-year-old woman with congenital absence of a mandibular lateral incisor was successfully rehabilitated using a direct composite resin-bonded fixed partial denture (RBFPD). DISCUSSION: Two specialized three-dimensional (3D)-printed flexible indices stabilized by a custom-designed 3D-printed rigid holder were employed to ensure the meticulous injection molding of flowable composite resins formulated to emulate the inherent chromatic gradations between dentin and enamel. The inherent flexibility of the indices, combined with the holder, facilitated accurate and seamless adaptation to the complex morphological features of the dental arch, thereby mitigating the challenges commonly associated with rigid 3D-printed resin indices. CONCLUSIONS: The bilayered direct composite RBFPD using 3D printed flexible indices prepared with a full digital workflow has several advantages over other dental prosthetic solutions, including noninvasiveness, cost-effectiveness, biomimetic esthetics, repairability, and shortened treatment times. Although the initial results are promising, further longitudinal studies with larger patient cohorts are required to confirm the long-term efficacy of this approach.

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BACKGROUND: Prosthodontics are often performed to treat patients with malocclusion and dentition defects. However, single prosthodontics cannot properly correct the disharmony of teeth, dental arch and other parts affected by malocclusion, and some patients may have difficulty in recovering the occlusal function due to poor prosthodontics. OBJECTIVE: This study aims to investigate the effect of orthodontics combined with fibre-reinforced composite resin-bonded fixed partial denture (FRC-RBFPD) on anterior dentition defects with minimal vertical intermaxillary space. METHODS: Sixty-two patients with anterior dentition defects with minimal vertical mandibular space admitted to our hospital between March 2021 and May 2023 were enrolled in this study. The participants were divided into the observation group (31 cases) and the control group (31 cases), according to the treatment plan. The control group was treated with traditional therapy, and the observation group was treated with orthodontic combined FRC-RBFPD therapy. Periodontal conditions (periodontal pocket depth [PD], the plaque index [PLI], the sulcus bleeding index [SBI]), levels of inflammatory factors in gingival crevicular fluid (high mobility group box 1 [HMGB1]), myeloid cell triggering receptor-1 (TREM-1), monocyte chemoattractant protein-1 (MCP-1), pain (visual analogue scale [VAS]), the clinical response rate and the incidence of adverse reactions were collected and compared. RESULTS: After 1, 3, 5 and 9 months following treatment, the scores of the PD, PLI, SBI, HMGB1, VAS, TREM-1 and MCP-1 in the observation group were found to be lower than those in the control group (FPD treatment= 352.532, FPLI score treatment= 112.341, FSBI score treatment= 79.479, FVAS score treatment= 96.132, FHMGB1 treatment= 52.532, FTREM-1 score treatment= 64.593, FMCP-1 score treatment= 53.582, and they were all statistically significant P< 0.05). There was a statistically significant difference in the response rate between the two groups (97.77% vs. 80.65%, χ2= 4.026, P= 0.045). No statistically significant difference was observed in the incidence of adverse reactions between the two groups (6.45% vs. 16.13%, χ2= 1.449, P= 0.229). CONCLUSION: Orthodontics combined with FRC-RBFPD shows an ideal restorative effect on patients with anterior dentition defects and minimal vertical intermaxillary space.

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This case report presents a challenging case of catastrophic failure of a fixed partial denture involving fracture of the prosthesis as well as supporting implants and teeth. The use of robotics facilitated efficient and successful restoration of the patient's dentition. After extraction of 2 fractured teeth and 1 fractured implant, 2 new implants were placed with haptic guidance from robotics, which allowed for stable osteotomies and high initial implant stability quotients. Due to the patient's tremors and heavy occlusal forces, restoration was delayed to allow the surgical site to heal, and the patient received a provisional partial denture. With subsequent placement of the final restoration, the treatment was fully completed in 4.5 months and required only a single surgical procedure. The use of haptic robotics in this case allowed for accurate planning, spacing, and placement of screw-retained implants with an optimal arch, leading to the best long-term outcome for the patient.

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OBJECTIVES: The effect of the implant position within the prosthesis on bone remodeling is scarcely documented so far. Thus, the aim of the present study was to investigate whether central implants may suffer higher peri-implant marginal bone levels (MBL) compared to laterals in case of fixed splinted bridges supported by ≥ three implants. MATERIALS AND METHODS: Partially edentulous subjects rehabilitated with at least one fixed bridge supported by ≥ three dental implants were enrolled. MBL was assessed radiographically by means of intraoral radiographs acquired with phosphor plates and imported in a dedicated software. MBL was calculated as the distance between the implant platform level and the most coronal visible bone-to-implant contact. A three-level linear mixed effects model was used for investigating the fixed effect of patient-, prosthesis-, and implant-level variables on the MBL. RESULTS: Overall, 90 patients rehabilitated with 130 splinted fixed bridges supported by 412 implants were included. The median follow-up was 136 months. The mean peri-implant MBL resulted statistically significantly higher at central implants if compared to lateral implants (p < .01). The estimated MBL averages for central and external implants were 1.68 and 1.18 mm, respectively. The prosthesis-level variables suggested that a cement-retained bridge was prone to a significant 0.82 mm higher MBL than a screw-retained one. Implant surface showed an association with MBL changes, although less pronounced than implant retention. CONCLUSIONS: In case of ≥3 adjacent implants supporting splinted bridges, central implants were more predisposed to MBL compared to laterals. At the prosthesis level, implants supporting cement-retained bridges were statistically more susceptible to MBL compared to screw-retained ones. Surface characteristics can also influence MBL stability at the implant level.

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PURPOSE: This study aimed to determine the usefulness of machine learning techniques, specifically supervised and unsupervised learning, for assessing the cementation condition between a fixed partial denture (FPD) and its abutment using a resonance frequency analysis (RFA) system. METHODS: An in vitro mandibular model was used with a single crown and three-unit bridge made of a high-gold alloy. Two cementation conditions for the single crown and its abutment were set: cemented and uncemented. Four cementation conditions were set for the bridge and abutments: both crowns were firmly cemented, only the premolar crown was cemented, only the molar crown was cemented, and both crowns were uncemented. For RFA under cementation conditions, 16 impulsive forces were directly applied to the buccal side of the tested tooth at a frequency of 4 Hz using a Periotest device. Frequency responses were measured using a 3D accelerometer mounted on the occlusal surface of the tested tooth. Both supervised and unsupervised learning methods were used to analyze the datasets. RESULTS: Using supervised learning, the fully cemented condition had the highest feature importance scores at approximately 3000 Hz; the partially cemented condition had the highest scores between 1000 and 2000 Hz; and the highest scores for the uncemented condition were observed between 0 and 500 Hz. Using unsupervised learning, the uncemented and partially cemented conditions exhibited the highest anomaly scores. CONCLUSIONS: Machine learning combined with RFA exhibits good potential to assess the cementation condition of an FPD and hence facilitate the early diagnosis of FPD retention loss.

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INTRODUCTION: The association of the periodontium with the fixed prosthesis is the basis of prosthetic rehabilitation. This prospective case series aimed to evaluate periodontal health through the relation between periodontal/peri-implant disease progression and the use of fixed partial dentures (FPDs). METHODS: Probing depth (PD), clinical attachment level (CAL), gingival index (GI), and plaque index (PI) on either teeth or implants were evaluated at up to 25-year follow-up and compared with the baseline. Statistical analysis was performed using the Kaplan-Meier test (p⟨0.05). RESULTS: The prospective evaluation showed that the patients maintained adequate periodontal health. Failure (severe periodontal stages) occurred in 12.5% of patients. The survival rate for 107 teeth/implants was 80.48%. The comparisons for clinical parameters revealed no statistically significant difference (p⟩ 0.05). At T1, the measurements for anterior and posterior regions, respectively, were PD =2.7mm and 3.1mm; CAL= 3.3mm and 3.6mm; GI=0.5 (both regions); and PI=0.79 and 0.62. Periodontal/peri-implant disease progression did not relate to the use of prostheses. CONCLUSIONS: Patients with more frequent follow-up appointments and lower GI and PI showed periodontal health for longer periods. Patients with different oral hygiene levels present different periodontal disease progression. Periodic hygiene control and motivation are vital factors for extensive oral rehabilitation success.

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BACKGROUND: The issue of an increase in pulpal temperature affects direct and indirect techniques, where the fabricating material will come in direct contact with the prepared teeth. OBJECTIVE: The aim of this study was to assess the pulpal thermal variations during provisional fabrication using direct and indirect-direct techniques, with three commonly commercially available provisional fabricating materials. METHOD: In this vitro analytical study, 120 extracted human teeth were placed in a dentulous mould and dental stone was poured, to create a working model with an embedded natural right maxillary central incisor. Recording of thermal changes in the pulp chamber during provisionalization with direct (technique 1) and indirect-direct (technique 2) using three common types of provisional crown materials. 120 provisional crowns were fabricated using polymethyl methacrylate (DPI) (Group 1), Bis-acryl composite (Protemp 4) (Group 2) and Visible-light polymerizing (VLP) Urethane Dimethacrylate (Revotek LC) (Group 3) by two techniques and recording of peak temperature changes were done. Temperature rise in the pulp chamber was recorded using a thermocouple. RESULTS: The mean initial and final temperature of the pulp chamber recorded for Groups 1, 2 and 3 was 31.52, 32.56; 31.01, 32.34; 32.29, 34.47 for technique 1 and 29.13, 30.5; 29.29, 31.11; 30.31, 32.65 for technique 2. The mean change in temperature was higher in Group 3 compared to the other groups. CONCLUSION: The temperature rise detected according to this study was within the safer pulpal health limits with all the investigated materials and techniques. The resin material recommended for clinical use when the direct technique is employed for the fabrication of provisional crowns is bis-acryl composite resin (Protemp-4) as it caused minimal temperature rise in the pulpal chamber.

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