Factors associated with furcation involvement and fixed prostheses: A cross-sectional study.

OBJECTIVE: The study aims to explore the relationship between horizontal and vertical furcation involvement (FI) in teeth with or without a single unit fixed prosthesis (FP). MATERIALS AND METHODS: Adult subjects presenting to the periodontics department requiring cone beam computed tomography (CBCT) analysis were recruited for this study. 79 patients, with a total of 200 teeth, were split into two groups based on the presence or absence of FP within the same patient. Our analysis considered patient-level factors like smoking, diabetes, and periodontal severity and tooth-level factors including root trunk length (RTL), probing depth (PD), periodontal supracrestal tissue height (STH), supracrestal tissue attachment (STH-PD), interproximal bone distance (IPBD) to the cementoenamel junction (CEJ) (control) or crown margin (Test), and the distance from the furcation to the CEJ (control) or crown margin (Test). Subsequently, we developed a predictive model for FI. RESULTS: The presence of a prosthesis had a significant association with FI, with an odds ratio (OR) of 12.8 (p < 0.001). Other factors significantly correlated with FI were periodontitis (OR = 10.9; p = 0.006), buccal furcation site (OR = 5.70; p < 0.001), and PD (OR = 1.90; p = 0.027). FP placement increased IPBD by 1.08 mm (p < 0.001). The predictive model built for FI demonstrated a sensitivity of 92.9% and a specificity of 66.7%. CONCLUSIONS: Fixed prosthesis significantly influenced FI only in periodontitis patients. Factors such as periodontitis Stage, probing depth, and buccal site contribute to FI. The high sensitivity of the predictive model highlights the importance of considering these correlations during treatment planning. CLINICAL RELEVANCE: Comprehending FI factors is vital for devising customised treatment plans to halt disease progression and enhance outcomes of periodontal regenerative therapies.

Peri-implant Tissue Health and Bone Resorption in Implant- Supported Fixed Partial Rehabilitations.

PURPOSE: To evaluate peri-implant tissue health and bone resorption in patients with implant-supported fixed partial rehabilitations. In particular, possible correlations between plaque accumulation and bone loss, as well as other periimplant health parameters, were investigated. MATERIALS AND METHODS: A total of 44 patients rehabilitated with fixed implant-supported partial rehabilitations were included. The following parameters were recorded: spontaneous bleeding (SB), suppuration, bleeding on probing (BOP), plaque index (PI), and probing depth (PD). Periapical radiographs were taken to measure crestal bone loss (BL). A nonparametric test (Spearman rank coefficient; rs) was used to identify possible correlations between the clinical parameters recorded. RESULTS: A total of 121 implants were analyzed. Global PI and BOP were 49.58% and 20.25%, respectively. There were no cases of suppuration, and only 2 implants showed spontaneous bleeding. Mean BL was 1.53 mm (SD: 0.98). No implants showed peri-implantitis. There was a weak, statistically significant correlation between PI and BL (rs = 0.27, P [2-tailed] = .99) and between PI and the other peri-implant parameters (BOP: rs = 0.14, P = .14; PD: rs = 0.04, P = .65; SB: rs = -0.08, P = .34). A very weak correlation was also found between BL and BOP (rs = 0.1, P = .2) and between BL and PD (rs = 0.02, P = .7). Correlation was found between BL and age (rs = 0.13, P = .81) and between the other peri-implant parameters and age using dichotomization (> or < 65 years; PI: rs = -0.14, P = .11; PD: rs = -0.21, P = .01; BOP: rs = -0.21, P = .01; SB: rs = 0.05, P = .53). No statistically significant correlations were found between the clinical parameters evaluated and the sex or the dental arch treated (maxilla vs mandible). In contrast, the correlation between periodontal parameters and years elapsed since surgery (follow-up) was significant. CONCLUSIONS: The present research suggests that in implant-supported fixed partial rehabilitations, dental implants with greater plaque accumulation are more likely to present augmented probing depth, peri-implant inflammation, and bone loss, although the correlation is statistically very weak. Patient age and time of follow-up also significantly affected peri-implant health parameters.

A comparative in vitro analysis of various temporization materials with respect to pulp chamber temperature changes during polymerization.

AIM: (1) To compare the temperature rise in the pulp chamber with different resin materials used for making provisional fixed partial dentures in anterior and posterior region while using Polyvinylsiloxane impression materials as matrix. (2) To identify a superior provisionalization material based on the amount of heat dissipated suitable for anterior and posterior provisional fixed partial denture fabrication. SETTINGS AND DESIGN: Temporary crowns and bridges are integral to Fixed Prosthodontics. It has been observed that conventional fixed prosthesis temporisation materials release heat due to the exothermic polymerisation reaction. When such a provisional material is directly let to set on a vital tooth, the heat transfer causes irreversible changes in the pulp tissue depending of the degree of change. Hence, this study observes amount of heat generation in various materials during temporisation procedure, by simulating similar conditions. MATERIALS AND METHODS: Two Models were fabricated, one simulating missing lateral incisor (Model A) and another simulating missing first molar (Model B). Intact maxillary central incisors and canine for Model A and intact mandibular Second Premolar and Second Molar were selected to act as abutments. These abutment teeth were fitted with the tip of a K-type Thermocouple inside their pulp chambers and these were connected to a digital thermometer. Five temporisation materials were chosen for fabrication of temporary crowns through Direct technique. (1) polymethy methacrylate (Self Cure acrylic), (2) bisacryl composite (Protemp 4), (3) visible light cure urethane dimethacrylate (Revotec LC), (4) barium glass and fumed silica infused methacrylate (Dentsply Integrity) and (5)nano-hybrid composite (VOCO Structur 3). Ten observations were made for each provisional material on each model. During each observation, temperature rise was recorded at 30s interval from the time of application, through the peak and till a decrease in temperature is observed. Polyvinyl siloxane was used as matrix for all except light cure resin, where polypropylene sheet was used. STATISTICAL ANALYSIS USED: Anova test used for statistical. RESULTS: ANOVA test revealed that there was a significant difference in the temperature changes associated with the provisional restorative materials used. Among the five, polymethy methacrylate (self cure resin) showed the maximum rise in temperature, followed by bisacryl composite (Protemp 4), visible light cure urethane dimethacrylate (Revotec LC), barium glass and fumed silica infused methacrylate (Dentsply Integrity) and nano-hybrid composite (VOCO Structur 3). There was no comparable difference between Model A and B but an overall reduction of temperature rise was observed in model B. CONCLUSION: VOCO Structur 3 showed the least temperature rise in the pulp chamber, and overall temperature rise was less for model B which can be attributed to the residual dentin thickness.

Perio-prosthodontic pontic site management, part II: Pontic site reconstruction strategies to enhance the esthetic and biological outcomes.

OBJECTIVE: Ridge deformities are present in most patients after tooth extraction; these defects make the management of future implant and pontic sites challenging to deal with. The restorative team should be able to diagnose and treat these deformities to allow for successful outcomes. Many approaches have been described to reconstruct pontic sites, each with specific indications. This article describes the different approaches to reconstructing pontic sites and their indications to allow for a proper esthetic and biological environment for future restorations. CLINICAL CONSIDERATIONS: Depending on the severity of the defect, location, and the esthetic necessity, pontic site enhancement can be done through different approaches, some requiring soft tissue grafting, hard tissue grafting, or both. Understanding the indications of the treatment options is essential to allow the clinician to make the right therapeutic decision and achieve the best possible perio-prosthodontic outcomes. CONCLUSIONS: An adequate balance between the soft tissue and prosthetics is essential to achieve successful results on implant-supported or tooth-supported fixed dental prostheses (FDPs). Selecting the right approach to treat ridge deformities is necessary to increase treatment success, reduce over-treatment, and create a biologically sound environment for restorations. CLINICAL SIGNIFICANCE: Pontic site enhancement through reconstructive surgery will allow for esthetically pleasing and biologically stable results, allowing restorations to emulate natural structures lost after tooth extraction.

Sobrevivência em fadiga de coroas bioinspiradas bilaminadas: estudo in vitro / Fatigue survival rate of bioinspired bilaminar crowns: in vitro study

O objetivo deste estudo foi avaliar o comportamento biomecânico através da resistência à fadiga e análise por elementos finitos de coroas bioinspiradas bilaminadas com infraestruturas modificadas na superfície vestibular (Estudo A) e utilizando diferentes materiais cerâmicos com módulos elásticos distintos (Estudo B). Para isso, foram confeccionados 90 preparos para coroa total em resina epóxi G10, sobre os quais foram preparadas coroas bioinspiradas de acordo com os seguintes grupos: Estudo A - IC (infraestrutura convencional), IME (infraestrutura modificada estratificada) e IMC (infraestrutura modificada cimentada), todas confeccionadas em dissilicato de lítio (infraestrutura) + porcelana (recobrimento); Estudo B ­ DL+LEU (dissilicato de lítio + leucita), LEU+DL (leucita + dissilicato de lítio), CH+DL (cerâmica híbrida + dissilicato de lítio) e CH+LEU (cerâmica híbrida + leucita). Para o Estudo A, todas as infraestruturas foram usinadas; os recobrimentos dos grupos IC e IME foram confeccionados através da estratificação, e os recobrimentos do grupo IMC foram usinados. Já para o Estudo B, todas as peças foram usinadas, de acordo com o material cerâmico de cada grupo. Em seguida, foi realizada a cimentação adesiva dos recobrimentos sobre as infraestruturas (a depender do grupo) e das coroas sobre os preparos utilizando cimento resinoso fotopolimerizável (Variolink Esthetic LC). Após a cimentação, os espécimes foram submetidos ao teste de fadiga cíclica (10.000 ciclos, 20Hz), e como desfecho foram considerados dois eventos, em que o primeiro foi a ocorrência de trinca e/ou lascamento (evento 1) e o segundo foi a falha catastrófica do conjunto (evento 2). Os valores de carga e número de ciclos para falha em que foram observados os eventos 1 e 2 foram utilizados para realizar a análise de sobrevivência de acordo com Kaplan-Meier e Log-Rank (Mantel-Cox; 95%). As marcas de fratura e o modo de falha das coroas foram avaliados e classificados por estereomicroscópio óptico e microscópio eletrônico de varredura. Por fim, foi realizada análise por elementos finitos (FEA) para ambos os estudos, a fim de avaliar a distribuição de tensões sobre as coroas e interface adesiva. Para o Estudo A, os resultados do teste de fadiga mostraram que, considerando o evento 1 (trinca/lascamento), os grupos IC e IMC apresentaram médias de carga fadiga estatisticamente significantes entre si (733,33 N e 913,33 N, respectivamente), enquanto o grupo IME apresentou média superior (1.020 N). O mesmo foi observado para o número de ciclos em fadiga para todos os grupos. Ao considerar o evento 2 (falha catastrófica), os três grupos apresentaram médias estatisticamente semelhantes entre si (~1.028 N). Os resultados de FEA mostraram que o grupo IC concentrou maior tensão de tração do que os grupos IME e IMC. Para o Estudo B, no teste de fadiga, o grupo DL+LEU apresentou a maior média de resistência à fadiga (evento 1: 913,33 N e evento 2: 1033,33 N), enquanto todas as outras combinações de materiais cerâmicos analisadas foram estatisticamente semelhantes entre si, considerando carga e número de ciclos. Com relação ao FEA, os grupos com cerâmica híbrida (CH+DL e CH+LEU) apresentaram menores picos de concentração de tensão na infraestrutura do que os grupos com cerâmicas vítreas (DL+LEU e LEU+DL), porém, em contrapartida, concentraram maior tensão na interface adesiva. Com isso, conclui-se que a utilização da infraestrutura modificada é uma alternativa viável e promissora para tratamentos reabilitadores, apresentando sobrevivência em fadiga e distribuição de tensões satisfatórias. Além disso, a combinação entre uma infraestrutura de dissilicato de lítio e recobrimento de cerâmica a base de leucita corresponde a melhor abordagem considerando a infraestrutura modificada.(AU)

The objective of this study was to evaluate the biomechanical behavior through fatigue resistance and finite element analysis of bilaminar bioinspired crowns with modified infrastructures on the buccal surface (Study A) and using different ceramic materials with different elastic moduli (Study B). For this, 90 preparations were made for a full crown in G10 epoxy resin, on which bioinspired crowns were prepared according to the following groups: Study A - CI (conventional infrastructure), SMI (stratified modified infrastructure) and CMI (cemented modified infrastructure ), all made of lithium disilicate (infrastructure) + porcelain (veneer); Study B ­ LD+LEU (lithium disilicate + leucite), LEU+LD (leucite + lithium disilicate), HC+LD (hybrid ceramic + lithium disilicate) and HC+LEU (hybrid ceramic + leucite). For Study A, all infrastructures were machined; the coverings of the CI and SMI groups were made through stratification technique, and the veneers of the SMI group were machined. For Study B, all pieces were machined, according to the ceramic material of each group. Then, the veneers were cemented into their infrastructures (depending on the group) and crowns were cemented into preparations using light-cured resin cement (Variolink Esthetic LC). After cementing, the specimens were subjected to the cyclic fatigue test (10,000 cycles, 20Hz), and as an outcome two events were considered: the occurrence of cracking and/or chipping (event 1) and catastrophic failure (event 2). The load (N) and number of cycles to failure in which events 1 and 2 were observed were used to perform the survival analysis according to Kaplan-Meier and Log-Rank (Mantel- Cox; 95%). The fracture marks and failure mode of the crowns were evaluated and classified by optical stereomicroscope and scanning electron microscope. Finally, finite element analysis (FEA) was performed for both studies in order to evaluate the stress distribution over the crowns and adhesive interface. For Study A, the results of the fatigue test showed that, considering event 1 (cracking/chipping), the CI and CMI groups presented average to failure that were statistically significant compared to each other (733.33 N and 913.33 N, respectively), while the SMI group showed higher averages (1,020 N). Same pattern was observed for the number of cycles under fatigue for both groups. When considering event 2 (catastrophic failure), the three groups presented statistically similar means (~1,028 N). The FEA results showed that the CI group concentrated greater tensile stress than the CMI and SMI groups. For Study B, in the fatigue test, the LC+LEU group presented the highest average fatigue resistance (event 1: 913.33 N and event 2: 1033.33 N), while all other combinations of ceramic materials analyzed were statistically similar to each other, considering load and number of cycles. Regarding FEA, the groups with hybrid ceramics (HC+LC and HC+LEU) showed lower stress concentration peaks in the infrastructure than the groups with glass ceramics (LC+LEU and LEU+LC), however, on the other hand, concentrated greater tension at the adhesive interface. With this, it is concluded that the use of modified infrastructure is a viable and promising alternative for oral rehabilitation treatments, presenting satisfactory fatigue survival and adequate stress distribution. Furthermore, the combination of a lithium disilicate infrastructure and a leucite-based ceramic coating corresponds to the best approach considering the modified infrastructure.(AU)

Aesthetic Dentistry - What You Decided and What I Want: Shade Selection

ABSTRACT Objective: To assess the relationship between patients' and dentists' perceptions of shade selection and its impact on satisfaction with the prosthesis. Material and Methods: A single group pre-post study was conducted at the Prosthodontics department of a teaching hospital in India. One hundred ten participants were selected through a systematic random sampling technique with inclusion and exclusion criteria. Patients' attitudes regarding the aesthetics of their maxillary anterior teeth were recorded using a validated questionnaire. Shades for the intended prosthetic crown selected by the dentist and chosen by the patient were recorded separately, and patient satisfaction with the appearance of the final prosthesis was recorded. We used descriptive statistics followed by Pearson's Chi-square test and a binomial logistic regression model for inferential statistics. Results: 109 participant's data were available for final analysis. Patients choose lighter shades than the dentist's selection, which is statistically significant (p=0.000). 73.4% were satisfied with the final prosthesis, and the binomial logistic regression model identified using patient-selected shade for the final prosthesis was significantly associated with patients' satisfaction with the final prosthesis (OR=3.3, p=0.001). Conclusion: The patient's preference should be considered with the dentist's option when selecting a shade to create good esthetics.

Successful complete oral rehabilitation of a patient with osteopetrosis with extensive pre-treatments, bone grafts, dental implants and fixed bridges: a multidisciplinary case report.

BACKGROUND: Osteopetrosis comprises a group of inherited disorders that are rare and result in abnormal bone structure. Bone remodeling is extremely inhibited because osteoclasts are nonfunctional or lacking. This condition causes overgrowth of bone with disappearance of the bone marrow, leading to aplastic anemia; obstruction of nerve passages in the skull leads to blindness and often hearing impairment. In most cases, osteopetrosis results in oral complications such as tooth deformation, hypomineralization, and delayed or absent tooth eruption. The only curative treatment is hematopoietic stem cell transplantation (HSCT). The main treatment of the oral complications during childhood and adolescence consists in protecting the erupted teeth against caries disease through prophylactic treatment aimed at optimal oral hygiene through frequent regular dental visits throughout life. Many patients with osteopetrosis require major oral rehabilitation to treat complications of the disease. Improved results of HSCT increase the likelihood that dental professionals will encounter patients with osteopetrosis. CASE PRESENTATION: In this case report, we show that individuals with osteopetrosis who have severe oral complications can be treated successfully if they are treated for osteopetrosis at an early age. The boy had his dental care in pedodontics, and regular multidisciplinary meetings were held for future treatment planning. At the age of 15, he was then referred for rehabilitation. The initial evaluations revealed no further growth in the alveolar bone. The rehabilitation was done stepwise, with extraction of malformed and malpositioned teeth. Initially, the patient received a removable partial denture followed by reconstruction of the width of the alveolar process, titanium implants, temporary fixed bridges, and finally screw-retained titanium-ceramic bridges with titanium frames for the upper and lower jaws. CONCLUSIONS: The three-year follow-up after loading indicated a stable marginal bone level and optimal oral hygiene as a result of frequent professional oral hygiene care. The patient showed no signs of symptoms from the temporomandibular joint and has adapted to the new jaw relation without any functional or phonetical issues.

Plaque accumulation on the fitting surface of full-arch implant-supported fixed prostheses with contact or noncontact pontics: A split mouth randomized controlled trial.

OBJECTIVE: To explore the differences in plaque accumulation on the fitting surface of full-arch implant-supported fixed prostheses with contact or noncontact pontics. MATERIALS AND METHODS: Nineteen patients (20 prostheses, 7 in the maxilla, and 13 in the mandible) intending to undergo full-arch implant-supported immediate function prostheses were recruited. During immediate restoration and using the midline as the boundary, one side was restored as a pontic and mucosa noncontact type (the test group), and the opposite side was restored as a pontic and mucosa contact type (the control group). In a follow-up 6 months after the surgery, the cleanliness of the fitting surface of the immediate prosthesis was evaluated by plaque staining and debris index determination. Patient satisfaction was investigated by questionnaire. RESULTS: Twenty prostheses from 19 patients included in the randomized controlled trial were followed up. Among the 20 prostheses, the percentage of area covered with plaque was significantly lower in the test group compared with that in the control group (31.5 ± 15.8% vs. 43.7 ± 15.3%; p < 0.001). The debris index in the test group was lower than that in the control group, although the difference was not statistically significant (2.77 ± 0.73 vs. 3.15 ± 0.90; p > 0.05). In the patient satisfaction survey, most of the patients were satisfied with most aspects of the prostheses, however, nearly half of the patients were not satisfied with the cleaning. CONCLUSIONS: The pontic and mucosa noncontact prosthetic design reduces plaque accumulation on the fitting surface, which is beneficial for maintaining oral cleanliness. However, the majority of study samples were mandible and conclusions may not be fully applicable to maxilla. TRIAL REGISTRATION: www.chictr.org.cn (ChiCTR1900028576). CLINICAL SIGNIFICANCE: The noncontact design in full-arch implant-supported fixed prostheses may be an effective measure of improving oral hygiene promotion. There is need for more research that can further improve oral hygiene of patients with full-arch implant-supported prostheses.

Impact of dental restorations and removable prostheses on potentially malignant oral mucosal disorders in the general population.

STATEMENT OF PROBLEM: Dental restorations and removable dental prostheses have been considered as risk factors for potentially malignant disorders of the oral mucosa. It remains unclear whether amalgam, composite resins, and prosthesis materials can induce potentially malignant disorders. PURPOSE: The purpose of this clinical study was to determine the relationship between the presence of amalgam and composite resin restorations, crowns and fixed partial dentures, and removable prostheses in potentially malignant disorders. MATERIAL AND METHODS: The data of 6041 participants in the population-based Studies of Health in Pomerania (SHIP) were accessed. Potentially malignant disorders had been clinically diagnosed by calibrated dentists and documented with photographs. Dental treatment was subdivided into restored and replaced teeth. Dental restorations were subclassified as buccal composite resin or amalgam restorations. Prosthetic treatment was subclassified into removable partial or complete prostheses and definitive restorations with crowns and fixed partial dentures. RESULTS: In the maxilla, participants with removable prostheses had a higher incidence of potentially malignant disorders than participants not undergoing treatment with removable prostheses (OR 2.12; 95% CI: 1.08-4.18), but not in the mandible (OR 1.30; 95% CI: 0.67-2.53). The surfaces with composite resin restorations were associated with a slightly higher risk of mucosal lesions than those without the restorations (OR 1.04; 95% CI: 1.01-1.07). No significant association was found between amalgam restorations and mucosal lesions. CONCLUSIONS: Participants with removable prostheses have a higher risk of potentially malignant disorders. Composite resin restorations are associated with a higher risk of mucosal lesions, whereas no significant association was found between amalgam restorations and mucosal lesions.

Long-term retrospective clinical study of tooth-supported fixed partial dentures: A multifactorial analysis.

PURPOSE: To assess the influence of several factors on the survival of tooth-supported fixed partial dentures (FPDs) with vital and non-vital abutments. METHODS: The present retrospective cohort study was based on the records of patients treated with 3-to-7-unit tooth-supported FPDs with a minimum follow-up time of 6 months after prosthesis delivery. Cumulative survival rate (CSR) was calculated over the maximum follow-up period. Cox regression models were used to evaluate the association between the clinical covariates and prosthesis failure. RESULTS: A total of 331 FPDs in 229 patients were included. The CSRs were 90.1% and 77.6% after 5 and 10 years and 67.9% and 52.1% after 15 and 20 years, respectively. Tooth-supported FPD failure was more prevalent within the first years of prosthesis delivery. Loss of one or more abutment teeth and loss of prosthesis retention were the main reasons for failure. Smoking and type of prosthesis material significantly influenced the survival of FPDs. Abutment vitality, position of the non-vital abutment, or prosthesis length did not show any significant influence on the occurrence of prosthesis failure. CONCLUSIONS: Smoking and the type of prosthesis material are suggested to contribute to an increased rate of FPD failure irrespective of abutment vitality.

Evaluating the Marginal and Internal Discrepancy of Nickel-Chrome Copings Made on Fixed Partial Denture Implants with Conventional and 3D Printing Techniques.

AIM: This study aimed to evaluate the marginal and internal discrepancy of nickel-chrome (Ni-Cr) copings made on implant bridges with conventional and 3D printing techniques. MATERIALS AND METHODS: 30 three-unit Ni-Cr FDPs (60 copings) were made by 3D-printing technique (PolyJet group), lost-wax method with die spacer technique (die spacer group), and lost-wax method with burn-out the cap (burn-out cap group). Then, the frames obtained from the three methods were checked to examine the marginal discrepancy by stereomicroscope after preparation and polishing. The silicon replica method was used to investigate the internal discrepancy at 6 points (buccal portion of occlusal surface, lingual portion of occlusal surface, middle area of the axial surface in the lingual, middle area of the axial surface in the buccal, cervico-buccal area, and cervico-lingual area). Kolmogorov-Smirnov test was performed first to estimate the normality of data distribution. A one-way ANOVA and post hoc Tukey test were done for comparing marginal and internal discrepancies between groups. The significant level was considered p < 0.05. RESULTS: The mean ± standard deviation of marginal discrepancy in the PolyJet group, die spacer group, and burn-out cap group was 37.9 ± 15, 68.8 ± 31.8 and 42.7 ± 3.6 µm for buccal margins and 40.4 ± 12.3, 64 ± 21.7, and 42.4 ± 2.1 µm for lingual margins, respectively. The means of buccal and lingual marginal discrepancy in the burn-out cap group and PolyJet group were significantly lower than the die spacer group (p < 0.001). Marginal discrepancy was not statistically different between the burn-out cap group and the PolyJet group. The mean ± standard deviation of overall internal discrepancy in the PolyJet group, die spacer group, and burn-out cap group was 64.6 ± 3.7, 72 ± 22.2, and 58.7 ± 2 µm, respectively. There was a significant difference between the mean of internal discrepancy between three groups (p = 0.001). The mean of internal discrepancy of the burn-out cap group was significantly lower than the die spacer group (p = 0.001) and PolyJet group (p = 0.005). Internal discrepancy was not significantly different between the PolyJet group and the die spacer group (p = 0.168). CONCLUSION: The marginal and internal gap rates of the three groups were within clinically acceptable limits. The 3D printing technique and lost-wax method with burn-out the cap had the lowest buccal and lingual marginal discrepancies. The burn-out cap method had better fitness and less internal discrepancy than 3D printing and die spacer groups. CLINICAL SIGNIFICANCE: Lower marginal discrepancy of copings fabricated by using 3D printed patterns may improve clinical success of implant restoration. How to cite this article: Ziaei M, Bajoghli F, Sabouhi M, et al. Evaluating the Marginal and Internal Discrepancy of Nickel-Chrome Copings Made on Fixed Partial Denture Implants with Conventional and 3D Printing Techniques. J Contemp Dent Pract 2023;24(11):826-833.

Comparison of Accuracy and Time for Four Implant Placement Techniques Supporting Fixed-Partial Denture.

Various guiding methods are used to place implants. This ex vivo pilot study used a convenience sample to examine time and accuracy for placement of 2 dental implants supporting a 3-unit fixed prosthesis on a simulation model using freehand and 3 guided placement techniques. Four operators with no prior implant placement experiences were randomly assigned placement of 2 maxillary or mandibular implants for a fixed prosthesis. Techniques included dynamic navigation (DN), static guide (SG), template-based guide (TBG), and freehand placement (FH). Preoperative and operative times were recorded. Discrepancies between the planned and placed implant positions were assessed by superimposing preoperative and postoperative cone beam computerized tomography scans. Data were analyzed with repeated-measures regression with Tukey's adjusted pairwise comparisons (α = 0.05). Dynamic navigation was associated with the longest operative time (13.5 minutes vs 5-10.2, P = .0001) but overall fastest when incorporating preoperative time (32.1 minutes vs 143-181.5, P < .0001). All deviation measures were significantly associated with the placement method (P < .05) except apex vertical deviation (P = .3925). Implants placed by SG had significantly lower entry 2-dimensional deviation than the other methods, particularly on the mandible. The DN and SG methods had significantly lower Apex 3D and overall angle deviations, again particularly on the mandible. The mandible had significantly higher deviations than maxilla. Within limitations of this study, implant placement by novice operators is more accurate when using dynamic and static guidance compared to freehand and template-based techniques.

Navigation guided socket-shield technique for implant and pontic sites in the esthetic zone: A proof-of-concept 1-year prospective study with immediate implant placement and loading.

OBJECTIVE: To assess clinical, radiological performance of novel navigation guided socket-shield technique (NSS) with immediate implant placement and loading. MATERIALS AND METHODS: Eighteen patients (12 females; age 52.54 ± 4.92; 33-72) treated between January 2018 and June 2019, were investigated, and followed for at least 1 year after definitive prosthesis placement (mean 20.1 months, 18-23). Primary outcomes: implant and prosthetic success rates, surgical, biologic, prosthetic complications. SECONDARY OUTCOMES: marginal bone loss (MBL), implant stability quotient (ISQ), pink esthetic score (PES), plaque and bleeding indexes. RESULTS: Sixty-nine navigation guided socket-shield procedures were performed (27 implant-sites and 42 pontic-sites) and 27 implants (NobelParallel, NobelBiocare AG) positioned and immediately loaded. Mean insertion torque and ISQ at implant positioning were 49 ± 5.34 Ncm (36-74), 73 ± 5.72 (68-81). No implant failure was experienced. Two root-shield exposures with mucositis, ulceration and bleeding were reported at two pontic-sites (2.9%) and successfully treated. No complications were experienced at implant-site leading to an overall NSS success-rate of 100%. No prosthetic complications occurred. Mean MBL was -0.72 ± 0.26 mm (-0.42 to -1.06 mm). PES final at the last follow-up 12.84 ± 0.92. The plaque and bleeding scores were 18.5 ± 6.12 and 3.15 ± 2.21. CONCLUSIONS: Within study limitations, dynamic navigation was effective to streamline execution of socket-shield technique at implant and pontic sites, shortening treatment time and reducing complications. Navigation guided socket-shield technique was reliable to achieve digitally planned shield-to-implant distance, facilitate immediate implant placement and loading and establish the mucosal dimension needed for underlying bone-to-implant protection and esthetic integration. CLINICAL SIGNIFICANCE: The investigated NSS technique overcomes the difficulties related to root preparation at implant and pontic-sites, facilitating immediate implant placement and loading. Dynamic guided surgery contributed to make socket-shield technique less technical-sensitive, shortening time for execution, reducing complication rate.

White discharge formation following a subepithelial connective tissue graft for anterior fixed partial denture pontics: A case report based on clinical and histological findings.

PATIENT: A 54-year-old woman presenting with anterior alveolar ridge resorption was submitted to a connective tissue graft (CTG) for esthetic improvement before rehabilitation with a fixed partial denture. Palate-harvested connective tissue was used as a graft after extra-oral removal of the epithelium. Unexpectedly, complete wound healing was not observed. Moreover, 6 months post-surgery, a white discharge was detected at the grafted site. The adjacent tooth showing a root fracture was initially associated with the symptoms and was then extracted. Concomitantly, the unhealed tissue at the grafted site was also excised, leading to temporary symptom resolution. However, the white discharge reappeared after 2 months. The excision area was expanded to remove the grafted tissue entirely, and the wound was completely healed. Since the alveolar ridge resorption had become larger compared to the preoperative condition, the patient was subjected to a second CTG, now using a connective tissue harvested from the palate by a single incision technique. The wound healed uneventfully, and the final prosthesis was delivered 6 months after soft tissue stabilization. The patient has been followed-up for more than 28 months without any recurrence of white discharge. DISCUSSION: Histopathological and cytological examination detected keratinized epithelial tissues and cells, respectively, in excised tissues and white discharge specimens. Consequently, a possible relationship between white discharge and residual epithelium in the harvested graft was strongly suspected. CONCLUSION: Success of the CTG procedure requires careful method selection for tissue transplantation and treatment execution.

Patients' Management Patterns for Restorative Treatment Procedures: A 4-Year Overview at the Restorative Clinic of a Tertiary Hospital in Nigeria

Abstract Objective: To determine the patients' management pattern for restorative treatment procedures at the Restorative Dentistry Clinic at the Lagos State University Teaching Hospital (LASUTH). Material and Methods: A descriptive and retrospective study design was employed to determine patients' management patterns for the restorative treatment procedures at the Restorative Dentistry Clinic at LASUTH. Treatment records of patients who attended the Restorative Clinic at the Lagos State University Hospital, Ikeja, Lagos, Nigeria, from 2011 to 2014 were reviewed; the effective treatments during the period under review were recorded as treatment procedures and were recorded as operative, endodontic, fixed prosthodontics, and removable procedures. Results: A total of 14,437 (75%) operative; 1,353 (7.0%) endodontic; and 559 (2.9%) fixed prosthodontics and 2,852 (14.9%) removable prosthodontic procedures were carried out during the period under review. This study showed that operative procedures were the most performed restorative procedures, whereas removable prosthodontics and endodontic procedures ranked second and third, respectively, to operative procedures. Fixed prosthodontics procedures were the least performed restorative procedures. Conclusion: This study showed that more efforts were being expended by dentists on operative services compared to endodontic, removable, and fixed prosthodontics services combined. Comprehensive studies, embracing all disciplines of dentistry, should be carried out to determine the level of demand and clinical relevance of procedures in clinical dental practice and hence to set specific and general objectives of dental education for the populace. Access to dental health Insurance services should also be increased in the country.

Clinical assessment of two inlay -retained bridge designs (proximal box-shaped and inlay shaped) in missing posterior teeth cases. (Randomized Clinical Trial) / Avaliação clínica de dois modelos de ponte fixa inlay (forma de caixa proximal e em forma de inlay) em casos de dentes posteriores ausentes. (Ensaio clínico randomizado)

Objective: This study aimed to evaluate the clinical performance of two inlay-retained bridge designs (proximal shaped and inlay shaped) in single missing posterior teeth cases. Material and Methods: A total of 70 cases with missing single posterior teeth were included in this study and divided into two groups with a 1:1 allocation ratio (n = 35 for each group). Group 1 (the control group): this group received an inlay retained bridge with inlay design on both abutments. Group 2 (the intervention group): this group received an inlay retained bridge with a proximal box on both abutments. PMMA resin (YAMAHACHI PMMA) was used for the try-in stage and monolithic zirconia (Katana, Kuraray) was used for the final restorations. The restoration surfaces were treated using sandblasting and Z-prime S (Bisco) and the cementation was done by using self-adhesive resin cement (Bisco). Fracture, marginal adaptation, postoperative sensitivity, caries, and gingivitis were assessed using the modified United States Public Health Service for restoration clinical assessments (MUSPHS standards) over 12 months of follow-up. Results: The results show there was no significant difference between the two groups. Kaplan-Meier survival curve was constructed to calculate the mean survival estimates of the two groups and we found that the two groups were clinically successful during a one-year follow-up. Conclusion: Both designs of inlay retained fixed dental prostheses revealed successful clinical performance in terms of Fracture, marginal adaptation, postoperative sensitivity, caries, and gingivitis (AU)

Objetivo: O objetivo deste estudo foi avaliar o desempenho clínico de dois modelos de ponte fixa por inlay (formato proximal e formato inlay) em casos de dentes posteriores perdidos. Material e Métodos: Um total de 70 casos com perda de um único dente posterior foi incluído neste estudo e dividido em dois grupos com uma razão de alocação de 1: 1 (n = 35 para cada grupo). Grupo 1 (grupo controle): Este grupo recebeu uma ponte fixa por inlay com deseho de inlay em ambos os pilares. Grupo 2 (grupo intervenção): Este grupo recebeu uma ponte fixa inlay com uma caixa proximal em ambos os pilares. Resina de PMMA (YAMAHACHI PMMA) foi usada para a etapa de try-in e a zircônia monolítica (Katana, Kuraray) foi utilizada para as restaurações finais. As superfícies das restaurações foram jateadas com Z-prime S (Bisco) e a cimentação realizada com cimento resinoso autoadesivo (Bisco). Fratura, adaptação marginal, sensibilidade pós-operatória, cárie e gengivite foram avaliadas usando o Serviço de Saúde Pública dos Estados Unidos modificado para avaliações clínicas de restauração (padrões MUSPHS) ao longo de 12 meses de acompanhamento. Resultados: Os resultados mostraram que não houve diferença significativa entre os dois grupos. A curva de sobrevida de Kaplan-Meier foi construída para calcular as estimativas de sobrevida média dos dois grupos e foi concluído que os dois grupos foram clinicamente bem-sucedidos durante um acompanhamento de um ano. Conclusão: Ambos os modelos de próteses dentárias fixas de inlay revelaram desempenho clínico bem-sucedido em termos de fratura, adaptação marginal, sensibilidade pós-operatória, cárie e gengivite(AU)

Single implant-supported two-unit cantilever fixed partial dentures in the posterior region: a retrospective case series with a mean follow-up of 6.5 years.

BACKGROUND: The aim of this retrospective study was to evaluate the implant survival, clinical and radiographic outcomes, and patient satisfaction of single implant-supported two-unit cantilever fixed partial dentures in the posterior region. METHODS: Patients who received a single implant-supported fixed partial denture with a cantilever in the posterior region between January 2004 and February 2018 were included. Survival rate of the implants and the fixed partial dentures and data regarding the marginal bone level, presence of plaque, calculus, bleeding on probing, mucosa health, pocket probing depth, and patient satisfaction were collected during an evaluation visit. Complications were recorded from the medical records. RESULTS: Twenty-three patients (mean age 64 ± 13 years) with 28 implants could be included in the study. The mean follow-up period was 6.5 ± 4.8 years at the time of data collection. The survival rate of the implants and fixed partial dentures was 100%. Mean marginal bone loss for the mesial and distal side of the implants was 0.41 mm (SD 1.18 mm) and 0.63 mm (SD 0.98 mm) respectively. A high prevalence of peri-implant-mucositis (89.3%) and peri-implantitis (17.9%) was observed as well as a limited number of technical complications. Patients were quite satisfied, as reflected by a mean VAS score of 94.0 ± 7.2 points (range 0-100) and a OHIP-NL49 score of 10.8 (range 0-196). CONCLUSIONS: Single implant-supported fixed partial dentures with a mesial or distal cantilever can be a predictable treatment option in the posterior region, with stable peri-implant bone levels, minor technical complications, and very content patients. However, the prevalence of peri-implant mucositis and peri-implantitis was high. TRIAL REGISTRATION: ISRCTN, ISRCTN79055740 , Registered on March 14, 2021 - -Retrospectively registered.

Tasa de supervivencia de prótesis fija unitaria de cerámica feldespática y feldespática reforzada / Survival rate of feldspathic and reinforced feldspathic ceramic single-unit fixed prostheses

Introducción: Gracias a su eficiencia y al uso exclusivo de cerámicas libres de metal, en rehabilitación oral se ha logrado alcanzar los estándares estéticos y mecánicos, manteniendo o, incluso, superando, la calidad de los tratamientos en comparación con las restauraciones metal cerámicas tradicionales. Actualmente los mecanismos de confeccion de cerámica libre están evolucionando cada vez mas hacia las tecnologías maquinadas CAD-CAM y disminuyendo su producción mediante la técnica de Inyeccion PRESS. Objetivo: Comparar la tasa de supervivencia de prótesis fija unitaria realizadas con cerámicas feldespáticas convencionales y reforzadas con disilicato de litio, confeccionadas con sistema CAD/CAM de CEREC® chair-side, en comparación con el método de inyección de laboratorio PRESS convencional de prensión. Métodos: Revisión sistemática realizada a través de búsqueda de evidencia científica en PubMed, PubMed Clinical Queries, Epistemónikos, Tripdatabase, Cochrane Library, recursos electrónicos de la Universidad de los Andes y bibliografía retrógrada, de artículos publicados hasta el año 2019. Se incluyeron todos aquellos estudios referentes a prótesis fija unitaria de cerámicas feldespática convencional y feldespática reforzada con disilicato de litio, confeccionadas mediante CAD/CAM y/o método convencional. Resultados: Un total de 28 artículos cumplieron los criterios de inclusión: 21 estudios observacionales de cohorte, 4 ensayos clínicos aleatorizados y 3 no aleatorizados. A corto y mediano plazo, CAD/CAM de CEREC® registró tasas de supervivencia de 98 por ciento y 91,9 por ciento, respectivamente. El sistema convencional registró tasas de supervivencia de 97,5 por ciento a corto plazo y 93 por ciento a mediano. Conclusiones: A corto plazo se describe en la literatura que CAD/CAM de CEREC® tuvo una tasa de supervivencia ligeramente superior al sistema convencional. Por otro lado, a mediano plazo CAD/CAM de CEREC® presentó una leve disminución respecto al sistema convencional. Aún no hay estudios disponibles para determinar la supervivencia clínica de los tratamientos a largo plazo(AU)

Introduction: Thanks to its efficiency and the exclusive use of metal-free ceramics, in oral rehabilitation it has been possible to achieve aesthetic and mechanical standards, maintaining or even exceeding the quality of the treatments compared to traditional metal-ceramic restorations. Currently, free ceramic manufacturing mechanisms are increasingly evolving towards CAD-CAM machined technologies and decreasing their conventional production through the PRESS Injection technique. Objective: Compare the survival rate of single-unit fixed prostheses made with conventional feldspathic ceramics and reinforced with lithium disilicate by the CEREC® CAD/CAM chairside system, with the conventional PRESS laboratory injection method. Methods: A systematic review was conducted of scientific evidence included in papers published until the year 2019 in PubMed, PubMed Clinical Queries, Epistemonikos, Tripdatabase, Cochrane Library, electronic resources of Los Andes Peruvian University, and retrograde bibliography. The papers selected dealt with conventional and lithium-disilicate reinforced feldspathic ceramic single-unit prostheses made by CAD/CAM and/or the conventional method. Results: A total 28 papers met the inclusion criteria. Of these, 21 were observational cohort studies, four were randomized clinical assays and three were non-randomized assays. Short- and mid-term, CEREC® CAD/CAM achieved survival rates of 98 percent and 91.9 percent, respectively. The conventional system achieved survival rates of 97.5 percent short-term and 93 percent mid-term. Conclusions: As described in the literature, CEREC® CAD/CAM had a slightly higher survival rate than the conventional system in the short term. In the medium term, however, CEREC® CAD/CAM displayed a slight reduction in comparison with the conventional system. No studies are available to determine the clinical survival of the treatments in the long term(AU)

A Radiographic and Clinical Comparison of Immediate vs. Early Loading (4 Weeks) of Implants with a New Thermo-Chemically Treated Surface: A Randomized Clinical Trial.

Background: Implant dentistry has evolved over time, resulting in better treatment outcomes for both patients and clinicians. The aim of this trial was to test whether the immediate loading of implants with a platform-switching design influences the marginal bone level, compared to four-week loading, after one year of follow-up. Moreover, a comparison of clinical data regarding implant survival, implant stability, and patient-reported outcome measures (PROMs) was conducted. Methods: Klockner® VEGA® implants with a ContacTi® surface were placed in partially edentulous patients in the posterior areas. Group A received an immediately loaded prosthesis (one week) and Group B received an early-loaded prosthesis (four weeks). All abutments were placed at the time of surgery. Radiographic and clinical data were recorded. Results: Twenty-one patients were treated (35 implants). No implants were lost during the study. The final marginal bone level did not show differences between groups. The bone loss at 12 months at the implant level was 0.00 mm for both groups (median). The final implant quotient stability (ISQ) values did not differ between groups (median 73 and 70.25), nor did the other clinical parameters or PROMs. Conclusions: The results suggest that neither of the loading protocols with the implants used influenced the marginal bone level-not the osseointegration rate, clinical conditions, or PROMs.