A Study of the Associated Risk Factors for Early Failure and the Effect of Photofunctionalisation in Full-Arch Immediate Loading Treatment Based on the All-on-Four Concept.

Early implant failure occurring within 1 year after implantation has been attributed to various factors. Particularly, early failure can lead to challenges in maintaining a full-arch prosthetic device, necessitating prompt intervention, including reoperation. This study aimed to retrospectively examine implant- and patient-related factors and the effects of photofunctionalisation associated with early failure in patients who underwent treatment using the all-on-four concept in both the maxilla and mandible. We conducted this retrospective study comprising 561 patients with 2364 implants who underwent implant-supported immediate loading with fixed full-arch rehabilitation using the all-on-four concept. We aimed to assess the survival rate within 1 year after implantation and determine the risk factors influencing early failure. The 1-year survival rates after implantation were 97.1% (patient level) and 98.9% (implant level) for the maxilla and 98.5% (patient level) and 99.6% (implant level) for the mandible. There was a significant difference in the implant-level survival rates between the maxilla and mandible, with a lower rate in the maxilla (p = 0.043). The risk factors associated with early implant failure according to the all-on-four concept included the maxilla (implant level) and smoking (patient level). We could not find a significant effect of photofunctionalisation on early failure (p = 0.25) following this treatment protocol.

Scanning accuracy with splinted and unsplinted implant scan bodies for the edentulous arch at implant level: an in vitro study.

Accuracy of completely edentulous arch scanning with implant scan bodies has not been completely validated for intraoral scanners. For desktop laboratory scanners validations were found in the literature. The aim of this in vitro study was to compare the dimensional accuracy of scanning with splinted and unsplinted scan bodies on a completely edentulous maxillary arch with 6 implants. A maxillary edentulous master cast with 6 implants was used as control for all implant level impressions. 6 implants were digitally planned and placed at different angulation of 0, 0  17° and 30°. A contact coordinate measuring machine (CMM) was used to generate baseline linear measurements of the master cast. Four test groups included: 2 intraoral scanners Trios (3shape, Copenhagen, Denmark) and True Definition (3M ESPE, St Paul, MN), one industrial scanner Atos (Core optical 3D scanner) and one conventional impression group scanned with laboratory scanner Dental Wings 7 Series. Each scan recording was made with splinted and unsplinted scan bodies. Digital datasets of all measurements were compared with the CMM baseline values using PolyWorks® InnovMetric Software in order to assess the linear and angular deviations and determine the accuracy of complete arch digital impression. Factorial ANOVA showed significant effect with splinting, scanner type, inter-implant distance and implant angulation for linear deviations. Splinted scan bodies revealed elevated linear and angular deviation values for all scanners with significantly highest deviations for True Definition scanner. Significant correlation was found between inter-implant distance and linear deviation (r =0.45, P =<0.001) with increased linear deviations among all scanners, regardless of splinting. ( P <0.05). Significant effect on accuracy was seen for angular deviation with splinting, scanner type and implant angulation; significant difference was found between 0° and 30° implant angulation ( P =0.035) with more deviation with 30° implant angulation. The accuracy of the complete arch implant digital impression using splinted scan bodies was significantly reduced for measurements that crossed the arch midline. The digital impression technique using a broad splint design to connect scan bodies was not found to improve the scan accuracy for intraoral scanners.

Sobrevida, éxito, y efecto en la calidad de vida del tratamiento con sobredentadura mandibular en el Servicio de Especialidades Dentales, Hospital Clínico San Borja Arriarán, Chile: estudio clínico prospectivo de 11 casos. Parte I / Survival, success, and effect on the quality of life of the treatment with mandibular overdenture in the Dental Specialties Service, Hospital Clínico San Borja Arriarán, Chile: prospective clinical study of 11 cases. Part I

RESUMEN: En los hospitales públicos chilenos, los pacientes desdentados mandibulares pueden ser tratados con una Sobredentadura-Mucosoportada, Implanto-Retenida (SMIR). Para tal fin, se adaptaron los lineamientos del plan piloto "Programa de Prestaciones Valoradas. Odontología 2012 Ministerio de Salud", en ausencia de una Guía Ministerial. El objetivo de esta serie de casos fue evaluar si la implementación y adaptación del plan piloto del tratamiento con SMIR mejoró la calidad de vida de los pacientes. Se evaluaron sobrevida, éxito implantario, e impacto en la calidad de vida. Los resultados indican una sobrevida y éxito implantario del 100% y una mejora de la calidad de vida. Conclusión: el tratamiento con SMIR mejora la calidad de vida de los pacientes, en el servicio público.

ABSTRACT: In Chilean public hospitals, patients with Complete Edentulous Mandible are treated with Implant-Retained and Mucosa-supported Overdenture (IRMO). For this purpose, the guidelines of the pilot plan "Valued Benefits Program in Dentistry 2012, Ministry of Health" have been adapted. The aim of this study was to evaluate whether these adapted protocols have been successful. We measured implant survival and success, and impact on quality of life with OHIP-14 criteria. Results indicate 100% implant survival and success and improved quality of life. Conclusion: IRMO improves patients' quality of life in public services.

Prevalence of Total Edentulism and Panoramic Radiographic Findings of Totally Edentulous Patients in a Dental School in Jeddah, Saudi Arabia.

Background The prevalence of total edentulism differs significantly between countries and between cities/regions within the same country. It can be affected by various factors, such as age, sex, and socioeconomic factors along with lifestyle and health behavior. Positive findings on panoramic radiographs are frequently observed in totally edentulous patients (TEP) during routine screening. Objectives This study aimed to retrospectively determine the prevalence of total edentulism and to evaluate the distribution and location of positive findings on panoramic radiographs of TEP at a dental school in Jeddah, Saudi Arabia. Methods A total of 12,428 digital panoramic radiographs of patients aged ≥35 years seeking treatment at a dental school from January 2018 to December 2021 were evaluated to determine the prevalence of total edentulism. Retained root stumps, impacted teeth, radiolucent, and radiopaque lesions were detected on the panoramic radiographs of the TEP. Data were analyzed using descriptive statistics. Results Among the 12,428 patients, 521 (4.2%) showed total edentulism on their panoramic radiographs. The prevalence of edentulism was the highest among patients aged >65 years (n=305, 4.5%), men (n=246, 4.2%), and non-Saudi citizens (n=300, 4.4%). A total of 198 radiographic findings were identified in 150 patients. The frequency rates of retained root stumps and impacted teeth were 19.2% (n=100) and 4.6% (n=24), respectively. Radiolucent and radiopaque lesions each accounted for 2.5% (n=13) of the lesions. Conclusions The prevalence of edentulism was higher in patients aged >65 years, male patients, and non-Saudi citizens. Retained root stumps were most often encountered among the four positive findings on panoramic radiographs. Considering the high frequency of positive radiographic findings in TEP, panoramic radiographs must be routinely obtained for TEP, but caution must be exercised to reduce the effects of radiation.

Evaluation of patient satisfaction and masticatory performance in mandible single implant-assisted overdenture.

OBJECTIVES: Many authors' have advocated a minimum of two implants to support a mandibular overdenture, but financial restraints specifically among the geriatric population in developing countries made this treatment plan economically difficult. Hence, this study was planned to assess the symphyseal (midline) single implant-assisted complete overdenture for patient satisfaction and masticatory performance. MATERIALS AND METHODS: In this clinical study, 12 edentulous first-time denture wearers underwent placement of a single implant in the mandibular symphyseal region. After 1 week, new complete dentures were fabricated and delivered to the patients. Post 3 months, the denture was fixed with a nylon cap-ball attachment to the anchor implant. Patients were questioned about comparison in the level of satisfaction and complaint before loading the implant (control group) and after 1 week, 1 month, and 3 months. The implant-assisted overdenture was fabricated with the help of a questionnaire. Masticatory performance was calculated with the help of a bite force measuring device at the same time intervals. SPSS 17.0 statistical software was used to analyze the data. RESULTS: It was found that single implant anchorage of the mandibular complete denture resulted in a significant increase (P < 0.05) in patient's subjective satisfaction and a decrease (P < 0.05) in complaints at the end of 3 months. There was a significant (P < 0.01) increase in bite force in implant overdenture after 3 months (5.459 kgf) as compared to that of the complete denture (3.406 kgf). CONCLUSION: Single implant-assisted overdenture can be an appropriate treatment modality to treat edentulousness in the geriatric population. It insinuates the remarkable improvement of prosthesis function and oral comfort with minor surgical procedures.

Comparison of psychometric properties of GOHAI, OHIP-14, and OHIP-EDENT as measures of oral health in complete edentulous patients aged 60 years and more.

OBJECTIVES: To compare the psychometric properties of three OHRQoL indicators (GOHAI, OHIP-14, and OHIP-EDENT) in a group of complete edentulous subjects and to explore the ability of these instruments to distinguish between individuals with different prosthetic and oral health status. METHODS: This was a cross-sectional study. Edentulous individuals aged 60 years and more were recruited between January 2019 and February 2020 in a medical and dental care centers. The Lebanese versions of GOHAI, OHIP-14, and OHIP-EDENT were used. External and internal consistencies were assessed using intraclass correlation coefficient (ICC) and Cronbach alpha, respectively. The concurrent validity was evaluated by testing the indicators against a proxy measure of a similar concept. To test their discriminative abilities, the ADD (GOHAI and OHIP) and SC (GOHAI and OHIP) scores were dichotomized according to the 25th and 75th percentile, respectively, and multivariate analyses were performed using sociodemographic, clinical, and subjective health parameters as explanatory variables. RESULTS: Two hundred and two edentulous subjects (age: 72.94 ± 7.378 years) were included. The proportion of subjects with no impact was lower for OHIP-EDENT (7.9%) compared to GOHAI (28.2%) and OHIP-14 (38.6%). Reproducibility was satisfactory for all OHRQoL tools since they were able to reproduce the results consistently in time (ICC > 0.80). The Cronbach alpha values were greater than 0.8 indicating acceptable internal consistency. The concurrent validity of the three tools was acceptable since subjects with lower OHRQoL score were less satisfied with their dentures and reported a higher need for self-rated therapy. Concerning the discriminant validity, OHIP-EDENT was more discriminant than OHIP-14 and GOHAI, since it was more able to identify patients with poor prosthetic issues or using instable denture. CONCLUSION: The OHIP-EDENT was more effective in identifying edentulous individuals with oral and prosthetic problems. Our results can help decide which dental instrument to use to assess the perception of oral health in edentulous individuals. More prospective studies are required to compare their evaluative properties.

Clinical guidelines for rehabilitation of the severely atrophic maxilla using extended-length subcrestal angulated implants and modified trans-sinus nasal protocol: A case report.

AIMS: Immediate fixed full-arch implant-supported prosthetic rehabilitation of the severely atrophic maxilla is a challenging treatment modality with favourable patient interest. The delivery of the treatment is challenging due to the difficulty in providing adequate posterior implant positioning with high primary stability in the absence of alveolar bone distal to the maxillary lateral incisors. Current trends in posterior implant placement and immediate loading include the placement of zygomatic implants or distally tilted implants placed anterior to the sinus cavity. The development of an extended-length subcrestal angulated implant gives an additional option to provide posterior occlusal support for reconstruction of the severely atrophic maxilla with an immediate full-arch fixed prosthesis. MATERIALS AND METHODS: This article describes a trans-sinus nasal protocol for fixed full-arch rehabilitation in the severely atrophic maxilla when the residual alveolar bone does not extend distally from the permanent maxillary lateral incisors. The extended-length distally tilted implant transverses a simultaneously augmented sinus cavity and engages the anterior maxilla and bone of the lateral nasal wall. RESULTS: The placement of an extended-length distal tilted implant placed the implant head at the crest of the alveolar ridge in the first permanent molar position, promoting favourable prosthetic biomechanics for a full-arch fixed prosthesis. Passivity of fit of the fixed prosthesis was achieved due to the 24-degree subcrestal angulation feature of the implant and use of multi-unit abutments.

Maintaining occlusal stability by selecting the most appropriate occlusal scheme in complete removable prosthesis.

The search of an adequate occlusal scheme that maximizes dentures' stability and patients' satisfaction is an ultimate objective in every complete prosthodontic treatment. Many studies compared occlusal schemes in terms of retention, comfort and masticatory performance. The purpose of this article is to review literature about different occlusal schemes related to complete dentures' stability and edentulous patients' satisfaction, in order to select the most appropriate occlusal scheme. Thus, an electronic search was performed from PubMed (MEDLINE), Scopus, Cochrane, Google Scholar and Sciencedirect databases. 65 articles were identified of which 56 were selected to compose the present article. Within the limitations of this review, it has been concluded that edentulous patients prefer anatomic occlusal schemes to non-anatomic teeth. Furthermore, canine guidance seems to be efficace in terms of chewing comfort and dentures' retention, as well as lingualized occlusion. However, bilateral balanced occlusion does not confer a long-term masticatory performance and satisfaction to edentulous patients.

The All-on-4 treatment concept for the rehabilitation of the completely edentulous mandible: A longitudinal study with 10 to 18 years of follow-up.

BACKGROUND: There is a need for studies evaluating the long term outcomes of the All-on-4 treatment concept. PURPOSE: To evaluate the long term clinical and radiographic outcomes of the All-on-4 treatment concept in the mandible. MATERIALS AND METHODS: This retrospective longitudinal case series study included 471 patients (women: 286, men: 185, average age = 57.7 years) rehabilitated with 1884 implants in immediate function supporting 471 fixed full-arch mandibular prostheses and followed for 10 to 18 years. Primary outcome measures were prosthetic survival and implant success and survival (estimated using life tables). Secondary outcome measures were marginal bone loss (MBL) at 10 and 15 years, biological and mechanical complications. Multivariable analysis was used to estimate potential risk indicators for implant failure (Cox regression to estimate hazard ratios and 95% confidence intervals (95%CI)), MBL > 3 mm at 10 and 15 years, biological and mechanical complications (binary logistic regression to estimate odds ratios [ORs] with 95%CI). RESULTS: Twenty-seven patients deceased (5.7%) and 149 patients (31.6%) were lost to follow-up. The cumulative prosthetic survival rate was 98.8%; the implant cumulative survival and success rate was 93% and 91.7%, respectively up to 18 years of follow-up. Previous biological complications (HR = 4.43) were significantly associated with implant failure. Average (95% CI) MBL at 10- and 15-years were 1.72 mm (95%CI: 1.59, 1.85) and 2.32 mm (95% CI: 1.98, 2.66). Smoking (OR = 2.72), previous failure of a contiguous implant (OR = 3.89) and biological complication (OR = 8.11) were associated with MBL > 3 mm. The incidence of biological complications was 11.8% at implant level, with previous failure of a contiguous implant (OR = 5.56), smoking (OR = 1.75), and systemic condition (OR = 1.65) were significantly associated. The incidence of mechanical complications was 36.7% with male gender (OR = 1.67) and type of prosthetic material used in the restoration significantly associated (metal-acrylic OR = 0.30; metal-ceramic OR = 0.22)). CONCLUSIONS: Considering the implant, prosthetic and MBL outcomes it is concluded that the All-on-4 is a viable treatment option validated in the long term. Nevertheless, biological and mechanical complications can occur.

Prosthetic rehabilitation using an obturator in a fully edentulous patient who had partial maxillectomy

Prosthetic rehabilitation of an edentulous patient who has a maxillary defect is difficult to achieve for many clinicians. The maxillary defect causes leakage of air during pronunciation and compromises denture stability, support and retention by reducing denture-bearing area and breaking peripheral seal. In these patients, the sizes and shapes of defects are very important factors which attribute to prognosis of maxillary obturators. This case report shows the prosthetic rehabilitation of the patient who had maxillectomy on the right maxillary sinus because of squamous cell carcinoma. The patient had a stepwise treatment protocol which started with pre-operative dental examination and followed by surgical, interim and definitive obturation phase. In this case, an acceptable level of retention could be obtained due to well-defined static defects and the preserved premaxillae and the patient was satisfied with the result of the treatment in the aspect of function and esthetics.

Prosthetic rehabilitation of a fully edentulous patient after maxillectomy: A case report / 대한치과보철학회지

Most patients with acquired maxillary surgical defects have difficulties such as functional impairments of mastication, speech, and deglutition as well as various degrees of facial deformity. The purpose of a prosthetic approach is to restore function and appearance with an obturator as normal as possible. This goal can be achieved when there is thoughful preoperative communication between a prosthodontist and a surgeon regarding a rehabilitation. In this case report, prosthetic rehabilitation was planned before the surgery for the patient diagnosed with squamous cell carcinoma in the right maxillary sinus with careful oral examination. Four months after maxillectomy, a definitive obturator was fabricated following the surgical and interim obturation phase. The objective of this case report is to describe the satisfactory results of the patient with improved rehabilitation of mastication, speech, deglutition, and appearance.

Implant supported fixed prosthesis for complete edentulous maxilla with severe alveolar ridge resorption: A case report / 대한치과보철학회지

Implant fixed prosthesis for the complete edentulous maxilla provides significant benefits in the aspects of functions and esthetics compared with the conventional denture. Implant supported fixed prosthesis are totally supported by implant, and thus stabilizes the prosthesis to the maximum degree as possible. Also, the improved retention and stability of fixed prosthesis enhance patients' psychological and psychosocial health. This clinical presentation describes a maxillary full arch implant-supported fixed prosthesis in complete maxillary edentulous patient who showed vertical and horizontal alveolar bone resorption in the anterior ridge. To rehabilitate the esthetics and proper lip support, the zirconia framework was fabricated and the pink porcelain was veneered to reproduce the natural gingival tissue. After 9 months of follow up, the restorations were maintained without complications and the patient was satisfied with the restoration both functionally and esthetically.

The evolution of dental materials for hybrid prosthesis.

Since the immemorial, the replacement of missing teeth has been a medical and cosmetic necessity for human kind. Nowadays, middle-aged population groups have experienced improved oral health, as compared to previous generations, and the percentage of edentulous adults can be expected to further decline. However, with the continued increase in the number of older adult population, it is anticipated that the need for some form of full-mouth restoration might increase from 53.8 million in 1991 to 61 million in 2020 [1]. Denture prosthetics has undergone many development stages since the first dentures were fabricated. The introduction of computer-aided design/computer aided manufacturing (CAD/CAM) has resulted in a more accurate manufacturing of prosthetic frameworks, greater accuracy of dental restorations, and in particular, implant supported prosthesis.

Avaliação de dois métodos de registro da relação central em desdentados totais / Evaluation of two methods for registering the centric relation in total edentulous

Objetivo: Comparar, no plano horizontal, as posições mandibulares determinadas por dois métodos de registro para determinação da posição de relação central (RC): inclinação da cabeça para trás (IC) os métodos guiado não forçado (GNF), em pacientes edêntulos. A hipótese nula é de que não haverá diferença entre os dois métodos. Material e Método: 20 pacientes desdentados totais foram selecionados para este estudo (n=20). Todos pacientes foram manipulados para posição de RC utilizando os métodos IC e GNF. A mensuração da posição de RC determinada por cada método foi registrada em um dispositivo extra-oral, cujas componentes foram fixados nos planos de orientação maxilar e mandibular. Para cada paciente, as duas posições de RC foram registradas no mesmo dispositivo extra-oral. Para mensurar as variações ânteroposteriores e laterais entre os pontos registrados por cada técnica, foi utilizado um projetor de perfil (Modelo 6C, Nikon/ USA). Os dados (mm) foram analisados estatisticamente utilizando o teste T (p<0.05) e o teste de correlação de Pearson. Resultados: A diferença entre a posição de RC obtida pelos métodos na posição ântero-posterior diferiu estatisticamente de zero (p=0.001) e que não houve diferença significante (p=0,479) quando comparada as posições de RC em relação à linha média: UHM (0,56±0,35mm) e IHB (0,65±0,52mm). Não foi observada correlação linear de Pearson entre as medidas lineares antero-posteriores e laterais dos métodos estudados (r=0,26; p=0,268>0,05). Conclusão: Pode-se concluir que método GNF gerou uma retrusão mandibular maior que o método IC.

Objective: To compare, in the horizontal plane, the mandibular positions determined by two methods for registering the centric relation (CR): inclination of the head backward (IHB) and unstrained hinging movement (UHM), in edentulous patients. The null hypothesis was that there is not difference between the two methods. Material and Methods: Twenty edentulous subjects were selected for this study (n=20). All patients were manipulated to CR position using the methods IHB and UHM. The CR measure of each method was registered in one extraoral device, which was fixed at the maxillary and mandibular record bases. For each patient, the two CR positions were registered in the same extraoral device. To measure the anteroposterior and lateral linear variations between the points registered for each technique, it was used a profile projector (Model 6C, Nikon/USA). The data (μm) were statistically analyzed using the Tukey test (p<0.05) and Pearson correlation test. Results: The difference between CR position obtained by the methods in anteroposterior position differed statically from zero (p=0.001) and that there was no significant difference (p=0.479) when compared the CR positions with the medium line: UHM (0.56±0.35ìm) and IHB (0.65±0.52ìm). It wasn’t observed Pearson linear correlation between the anteroposterior and lateral linear measures of the methods (r = 0.26; p = 0.268>0.05). Conclusion: It can be conclude that the method UHM presented a higher mandibular retrusion than the method IHB.