Implant-based Restorations Research Articles

Periodontal Tissue Responses to Restorations with and without Cervical Finish Line: A Systematic Review and Meta-analysis.

The purpose of this review was to evaluate the periodontal and peri-implant tissue responses to restorative approaches with and without cervical finish line on teeth and dental implants. An electronic search was performed in PubMed/MEDLINE, Embase, Cochrane Library, LILACS, Web of Science, and Scopus databases, and in the gray literature. Controlled clinical trials and prospective cohort studies were included. Analyzed outcomes included gingival index (GI), bleeding on probing (BOP), probing depth (PD), gingival thickness (GT), marginal stability (MS), and marginal bone loss (MBL). A meta-analysis was then performed in two parts: the first compared results of restorations on teeth with and without cervical finish line, and the second compared results of restorations on implant abutments with and without cervical finish line. Regarding the tooth-based restoration analysis, 7 out of 1,388 selected articles were included in the systematic review, and 2 were selected for the meta-analysis. For implantbased restorations on abutments with and without cervical finish line, 6 out of 707 selected articles were included in the systematic review, and 2 in the meta-analysis. No significant differences in periodontal and peri implant indexes were identified between both prosthetic approaches in situations with and without cervical finish lines.

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

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

Awareness On Management of Screw Fracture Among Dental Students and Practitioners

Dental implants have been a life-enhancing modality for partially and completely edentulous patients. Implants can successfully support a cemented or screw-retained single crown. However, this modality is not without complications. Despite the high success rate of implants, it is not free of complications and dental implants occasionally fail due to biological factors or technical complications.The technical problems of implant-based restoration components including abutment screw fracture and peri-implantitis are deeply related to dental implant system failure, and an increase in related complications are also being reported.A set of 12 questions was formulated and distributed among the study. The participants were asked to fill the questionnaire. The survey was conducted in an online forum. A total of 100 validated entries were collected. Data was entered into Microsoft Excel and analysed in SPSSV20. Associations between categorical variables were determined using Chi-square. P<0.05 was considered statistically significant.69.6% of the participants believe that screw loosening is the most common complication in single tooth implant.57% of the participants responded screw loosening might lead to screw fracture.50% of the participants responded screw fracture occurs at a rate of 1-5%.31 of the participants believe management of screw fracture can occur through implant removal and retreatment, fabrication of cemented cast cast and pore,screw fragment retrieval.82% of the participants are aware about the screw removal kit. Thus awareness on management of screw fracture among dental students and practitioners was established.

Design and Analysis of tool for fractured abutment screw removal from the dental implant body

Implant-based restoration is currently seen to be a more reliable option with higher success rates. Biological and technological problems, on the other hand, are common. An implant insertion complication well known to many is the loosening of the abutment screw. Fractures of the implant-abutment may cause the implant to fail to function efficiently as they may leave a fragment inside the implant. This study aimed to introduce the modified design of a tool to extract the stripped abutment screw from the implant body and to analyses the deformation, stress and strain acting on the tool using the finite element method.

Replacement of an existing maxillary anterior fixed dental prosthesis, redo another fixed dental prosthesis, or convert to implants.

The purpose of this article is to discuss the considerations that need to be evaluated when considering the replacement of an existing maxillary anterior fixed dental prosthesis (FDP) with another FDP, or when to consider converting to implants and individual crowns on the previous abutment teeth. The need to replace unesthetic or failing maxillary anterior FDPs is something all restorative dentists will be faced with multiple times in their careers. Given the emphasis over the past few decades on utilizing implants for tooth replacement as opposed to a tooth supported FDP, the question becomes when is converting the existing FDP to implants and single crowns an appropriate choice, as opposed to redoing a new FDP. This article will focus on the risks of choosing to convert to an implant solution, and the risks of redoing the tooth supported FDP. Multiple systematic reviews on each approach will be used to aid in the decision process. The most significant risks for both approaches will be identified, and a chart of the key parameters to assess will be presented, along with their impact. The statistical outcomes at 5 and 10 years of tooth supported FDPs, and Implant based restorations are very similar if certain clinical parameters are met, namely vital healthy abutment teeth for the FDP, and adequate bone and soft tissue for the implant-based restoration. If one abutment tooth is compromised the long-term prognosis drops significantly and converting to an implant-based restoration may be more predictable. Similarly, if adequate bone and soft tissue cannot be obtained through surgical augmentation procedures, using a connective tissue graft for the ridge, and redoing the FDP may obtain a more acceptable esthetic result. A significant number of maxillary anterior FDPs exist that will need replacement in the future. Given the desire of many dentists to utilize implants when possible, there can be a tendency to automatically treatment plan an implant-based approach for replacement of the existing FDP. Certainly, most clinicians would favor an implant-based tooth replacement rather than preparing unrestored teeth to place an FDP, but when an existing FDP exists, the teeth have already been prepared for full coverage in most instances. In addition, for most long term existing FDPs, there is a significant change in the vertical and horizontal dimension of the bone and soft tissue that can make getting an acceptable esthetic result with an implant challenging. This article provides a systematic approach to identifying when redoing the FDP may be preferable, or when converting to an implant-based approach is a better choice.

Prosthetic complications of fixed dental prostheses supported by locking-taper implants: a retrospective study with a mean follow-up of 5\xa0years

BackgroundRestoration with locking-taper implants is a widely used methodology. However, conical connection systems such as locking-taper implant systems have rarely been examined. This study provides a retrospective investigation of locking-taper fixed restorations, mainly focusing on prosthetic complications.MethodsPatients undergo treatment with conical connected implants from 2008 to 2010 were examined. Preparation of the implant sites was performed according to the standard procedures for the Bicon system. Bone healing took over 6 months, and the prosthetic procedure was initiated thereafter. Integrated abutment crowns or gold porcelain crowns were used, and the prosthesis type was a single crown or a fixed dental prosthesis. Once the crown was in place, its occlusion was thoroughly checked and adjusted, and then the crown was glazed or finely polished. The Kaplan–Meier method was used to calculate the cumulative complication-free rates for 5 and 10 years. Additionally, a Cox regression model was used to identify the factors that independently influenced the results. Implant survival and marginal bone loss were also investigated.ResultsA total of 392 patients who underwent 541 implants and 434 locking taper implant-based restorations from 2008 to 2010 were examined. The overall 5-year cumulative complication-free rate was 83.34%. The most common prosthetic complication was veneer chipping, with a frequency of 67.53%. According to the Cox regression model, the complication-free rate of integrated abutment crowns was significantly higher than that of gold porcelain crowns, that of molar regions was significantly higher than that of premolar regions, and that of females was significantly higher than that of males. Only three implant failures happened, and the mean marginal bone loss values at 1- year, 5-years and 10- years were 0.25 mm (95% CI ± 0.12), 0.40 mm (95% CI ± 0.03) and 0.51 mm (95% CI ± 0.05), respectively.ConclusionVeneer chipping was the most common complication with locking-taper implant-supported fixed restorations. The incidence of complications for IACs is significantly higher than that for GPCs. Age, location, and prosthesis type are not determinants of prosthetic complications. Besides, the long-term clinical effect of locking-taper implant can meet the clinical needs. The bone tissue level around the implant can maintain long-term stability.

Induced Membranes for Segmental Mandibular Reconstruction: Case Series and Technique Review

This article describes the induced membrane technique (IMT) and presents 10 cases in which the technique was applied for segmental mandibular reconstruction. Ten patients requiring segmental mandibular resection were reconstructed using the staged IMT. Mandibular resection, placement of a reconstruction plate and polymethylmethacrylate spacer, was performed. At the second procedure, the spacer was removed through a small incision and particulate autograft from the ilium was placed, in some cases with bone morphogenic protein. Nine of the 10 patients achieved bony continuity with the IMT. Spacers were designed to optimize mandibular form and future implant-based restoration. All patients have either had implants placed or have adequate bone for implant placement. The average hospital length of stay for both surgeries combined was 3.1 nights. The IMT can be successfully used to reconstruct segmental mandibular defects, allowing surgeons to create a neomandible with optimal form both for facial contour and for dental implant-based reconstruction.

Clinical Assessment of Preload Maintenance in the Abutment Screws of Single Posterior Implants After 1 Month of Use

Abutment screw loosening is a frequently encountered prosthetic complication in implant dentistry. Due to the detection of preload loss soon after initial torque application, abutment screw retightening 10 minutes after initial tightening has been recommended. The aim of this clinical study was to assess preload maintenance in the abutment screws of single posterior implants after 1 month of use by employing screw-cement-retained prostheses and a clinical assessing method, with the ultimate goal of helping to improve the clinical workflow of implant-based restorations. In total, 158 patients treated using three implant systems were divided randomly into two groups in which abutment screws were and were not retightened, respectively, approximately 10 minutes after initial torque application. Screw-cement-retained prostheses, which permitted the assessment of abutment screw preload maintenance and screw retightening after 1 month of use, were used. Preload loss at 1 month was defined as the failure to achieve the torque recommended for the abutment screws after 90-degree clockwise rotation of the screwdriver. The data were analyzed using binary logistic regression, with a significance level of P ≤ .05. No preload loss was detected 10 minutes after initial screw tightening. Preload loss was detected in 16 (10.13%) cases at 1 month after initial tightening, with no significant difference according to the implant system used, the presence or absence of retightening at 10 minutes after initial tightening, or implant position (premolar or molar). Under the experimental conditions of this study, abutment screws in some bone-level, internal tapered-connection, platform-switching implant systems showed preload loss at 1 month after abutment placement for single posterior implant-based restorations, regardless of implant system or whether abutment screws had been retightened 10 minutes after abutment placement, or implant position (premolar or molar). It is necessary to retorque the abutment screws 1 month after initial torque. The screw-cement-retained prostheses used in this study permit abutment screw retightening at that time and have advantages over traditional methods.

Impairments due to tooth loss and prosthetic expectations in patients from an urban area and a rural area in Sweden. A qualitative study.

To explore impairments due to tooth loss and expectations of prosthetic replacements in an urban group and a rural group of patients in Sweden. Semi-structured interviews were performed on 35 partially edentulous patients from prosthodontic specialist clinics located in an urban area and a rural area in Sweden. The interviews focused on impairments due to tooth loss and expectations of prosthetic restorations. Analysis was made using the grounded theory approach, allowing in-depth investigation of the phenomenon. Functional, aesthetic and social impairments were mentioned, and coping strategies (eg chewing differently and laughing less) and modifications (eg age, time and social setting) of the impairments were described. The rural patient group accepted impairments somewhat better than the urban one. Otherwise, there was only minor difference between the groups. Removable prosthodontic restorations were more acceptable among rural patients. Urban patients insisted more often on implant-based restorations and had higher expectations of longevity. Patients with minor impairments still wanted treatment, based on concerns about the future of their dentition. The interviews themselves generated new thoughts in the patients and were thus considered valuable by the patients. Impairments due to tooth loss and expectations of prosthetic replacements were expressed in the same way in the rural and urban patient groups. However, in the rural population, there was a higher acceptance of impairments and also of removable prosthetic restorations, whereas the urban population expressed a higher demand for implant-based restorations.

Oral health improvements in Switzerland over 20 years

While the time trends in oral health are favourable, differences still persist in dental status and in prosthetic dental restorations (PDR) between population subgroups. This study aimed to identify changes in oral health in Switzerland over two decades and to describe their relationship to sociodemographic factors in 2012. Swiss Health Surveys were conducted in 1992, 2002, and 2012. The mean number of missing teeth and the prevalence of PDR were calculated at each time point. Logistic regression analysis was performed to assess associations between the prevalence of PDR and sociodemographic factors. The mean number of missing teeth decreased from five in 1992 to three in 2012. Dental status - as indicated by the number of teeth present - improved across all sociodemographic groups, with the greatest improvements being found in obese participants and in participants with the lowest incomes and educational levels. The prevalence of implant-based restorations increased from 3.2% in 2002 to 9.8% in 2012, and the shift from fixed to removable restorations occurred in the age group being 10 years older. The overall prevalence of PDR decreased in middle-aged people. In conclusion, over the two decades of the study, the oral health of the Swiss population substantially improved. Although sociodemographic differences persisted, they decreased considerably in terms of the number of missing teeth and percentage of the population with a functional dentition.

Bio-Root and Implant-Based Restoration as a Tooth Replacement Alternative

We previously reported that dental stem cell–mediated bioengineered tooth root (bio-root) regeneration could restore tooth loss in a miniature pig model. As a potential new method for tooth restoration, it is essential to compare this method with the widely used commercial dental implant–based method of tooth restoration. Tooth loss models were created by extracting mandibular incisors from miniature pigs. Allogeneic periodontal ligament stem cells (PDLSCs) and dental pulp stem cells (DPSCs) were isolated and cultured. A PDLSC sheet was prepared by adding 20.0 µg/mL vitamin C to the culture medium; in addition, a hydroxyapatite tricalcium phosphate (HA/TCP)/DPSC graft was fabricated and cultured in a 3-dimensional culture system. A total of 46 bio-root implantations and 9 dental implants were inserted, and crown restorations were performed 6 mo after implantation. Histological, radiological, biomechanical, and elemental analyses were used to evaluate and compare tissue-engineered bio-roots and dental implants to the natural tooth roots. After 6 mo, both computed tomography scans and histological examinations showed that root-like structures and dentin-like tissues had formed. Three months after crown restoration, clinical assessments revealed that tooth function was equivalent in the regenerated bio-root and the dental implant. Biomechanical testing showed that the bio-roots were similar to natural tooth roots in compressive strength, modulus of elasticity, and torsional force; however, these properties were significantly higher in the dental implants. Elemental analysis revealed a higher similarity in elemental composition between bio-roots and natural tooth roots than between bio-roots and dental implants. However, the dental implant success rate was 100% (9 of 9) and the bio-root success rate was only 22% (10 of 46). Taken together, we showed that an allogeneic HA/TCP/DPSC/PDLSC sheet could successfully build a bio-root with structure and function similar to the natural tooth root; however, tissue engineering procedures must be optimized further to improve the success rate.