Accuracy of Digital Impressions at Varying Implant Depths: An In Vitro Study.

PURPOSE: Implants placed at variable depths may vary the amount of visible scannable surface of a scan body. Intraoral scanner technology uses advanced optical principles to record the surface of the scan body to accurately capture the implant position. The purpose of this study is to investigate the effect implant placement depth has on the accuracy of digital implant impressions using an intraoral scanner. MATERIALS AND METHODS: A partially edentulous gypsum master model was fabricated to allow the positioning of a single implant analog at different depths. Four groups were created based on the planned implant depths of 7, 6, 3, and 0 mm and corresponding visibility of the scan body at 2, 3, 6, and 9 mm. The model was digitized with a laboratory scanner for the reference scan and with an intraoral scanner to generate 15 test scans per group, with a total of 60 scans. The test scans were superimposed onto the reference scan using the best fit algorithm to analyze and measure the positional (dXYZ) and angular deviation (d⍬) of the scan body using three-dimensional metrology software. Statistical analysis was performed using a one-way ANOVA and pairwise comparison was done with a Tukey-Kramer HSD test (α = 0.05). RESULTS: The one-way ANOVA of the groups for the dXYZ and dθ parameters was statistically significant (F3,56 = 11.45, p < 0.001, F3,56 = 24.04, p < 0.001). Group D (9 mm) showed the least positional deviation at 38.41 µm (95% CI 30.26; 46.56) and the least angular deviation of 0.17° (95% CI 0.12; 0.21). Group A (2 mm) showed the greatest positional deviation of 77.17 µm (95% CI 65.23; 89.11) and greatest angular deviation of 0.84° (95% CI 0.65; 1.03). The positional and angular deviation increased with increased implant depth. CONCLUSIONS: The accuracy of digital impressions is influenced by the implant depth and the amount of visibility of the scan body. The trueness and precision are highest when the implant is placed at 0 mm depth with complete visibility of the scan body and decreases with subgingival implant placement.

Immediate Loading of Four Guided Unsplinted Narrow Implants Supporting a Maxillary Overdenture: A Minimally Invasive Approach.

INTRODUCTION: Little evidence is available on the loading protocols for implant-supported overdentures in the treatment of the edentulous maxilla. There are only a few case-reports available to document the feasibility of immediate loading for maxillary overdenture, and the majority of the publications include the use of splinted implants. This paper presents a case report of immediately loaded narrow diameter implants supporting a maxillary overdenture using Locator abutments. CASE PRESENTATION: A 64-year-old, fully edentulous patient presented with a maxillary complete removable denture. A dual cone beam computed tomography scan was obtained, and the surgical planning was performed. Four 3.3 mm diameter implants were placed at the lateral incisor and second premolar positions, using a guided and flapless approach. Locator abutments were placed, and the denture was connected immediately. The patient was instructed not to remove the prosthesis for 1 week and to follow a soft diet regimen for 2 weeks. Clinical and radiographic evaluation showed positive results at 12 months, with neither prosthetic nor implant complications. CONCLUSION: This is a proof of principle case report, which demonstrates the possibility of immediately loading four guided narrow diameter implants supporting a maxillary overdenture using a Locator retention system.

The effect of implant prosthesis complications on patient satisfaction.

STATEMENT OF PROBLEM: How complications regarding implant prostheses affect patient satisfaction and oral health-related quality of life (OHRQoL) is unclear. PURPOSE: The purpose of this retrospective study was to compare patient satisfaction with implant restorations in patients with or without a history of complications. These data were used to determine whether implant prosthesis complications affected self-reported OHRQoL. MATERIAL AND METHODS: Data were gathered from 176 edentulous and partially dentate patients who had received implant prostheses consisting of implant-supported crowns, implant-supported overdentures, and screw-retained fixed dental prostheses (FDPs) in predoctoral and postdoctoral clinics between January 1, 2010, and December 31, 2014. Demographics and complications were self-reported by means of a survey. Patients rated their OHRQoL using the Quality of Life with Implant-Prostheses (QoLIP-10) questionnaire. Means were compared by using a 1-way ANOVA to compare the variables of prosthesis complications, sociodemographic data, and patient satisfaction. Significantly different variables were further evaluated using a post hoc Tukey-Kramer Honestly Significant Different (HSD) test (α=.05). RESULTS: Statistically significant differences in patient satisfaction were found related to prosthesis complications, gender, and marital status. The most common complication for implant-supported crowns was screw loosening. For implant-supported overdentures and screw-retained FDPs, the most common complication was repair of the prosthesis. Those who had experienced complications reported lower OHRQoL scores than those who had not. Women and widows/widowers overall reported lower OHRQoL scores. The OHRQoL scores of women with and without prosthesis complications were not statistically different (P=.073). No significant differences were found relative to age (P=.937) or education (P=.302). Patients without complications with implant-supported crowns reported the lowest satisfaction because of oral hygiene difficulties. The lowest satisfaction in patients with complications of implant-supported overdentures and screw-retained FDPs was related to worry/concern because of problems with the implant prosthesis. CONCLUSIONS: The results of this survey suggest that patients who experience complications with an implant prosthesis report a lower OHRQoL score than those who do not. Future studies are needed to evaluate patient satisfaction by comparing prosthesis complications with and without implants to determine whether patients who have had complications with implant prostheses are more satisfied than those who have experienced complications with conventional prostheses.

Prosthodontic Management of Implant Therapy: Esthetic Complications.

The essential promise of implant dentistry is the ability to imperceptibly replace missing teeth. To achieve this, careful planning, execution, and maintenance is required by the dentist and patient to maintain a long-term esthetic and functional result. Unfortunately, as a result of biological, prosthetic, and iatrogenic factors, unesthetic results can occur. This article explores the potential causes for the unesthetic dental implant and the possible solutions that may improve the clinical situation. Whereas relatively simple errors may be corrected through prosthetic means, greater complications may require surgical intervention to achieve the desired result.

Comparison Of Full-Mouth Scaling and Quadrant-Wise Scaling in the Treatment of Adult Chronic Periodontitis.

In the search for the ideal treatment of periodontal disease various non-surgical techniques should be considered. The objective of this study was to evaluate the efficacy of full-mouth scaling (FMS) by clinical and microbiological parameters. 670 individuals were evaluated with 230 subjects meeting the selection criteria and were divided into two groups; 115 subjects treated with FMS and 115 treated with weekly sessions of scaling and root planning (SRP). The patient population had a mean age of 51.67 years, with moderate chronic periodontitis. Subjects were evaluated prior to treatment (T1) and 90 days after execution of therapy (T2), with regards to: probing depth (PD), clinical attachment level (CAL), plaque index (PI), gingival index (GI), and microbial detection for the presence of Porphyromonas gingivalis (P.g.) and Prevotella intermedia (P.i.) by culture method and confirmed by biochemical tests. Subjects treated in the FMS group also rinsed with 0.12% chlorhexidine mouthwash for seven days following treatment. The results were analyzed using statistical Student's t-test and chi-square test. No statistically significant differences were observed for PD and CAL between T1 and T2 in both groups. For GI and PI significant difference was observed between the groups. For the evaluated microbial parameters was observed reduction of P.g. and P.i., but only for P.g. with a significant reduction in both groups. The full mouth scaling technique with the methodology used in this study provided improved clinical conditions and reduction of P.g. in subjects with moderate periodontitis, optimizing the time spent in the therapeutic execution.

Comparison of full-mouth scaling and quadrant-wise scaling in the treatment of adult chronic periodontitis

Abstract In the search for the ideal treatment of periodontal disease various non-surgical techniques should be considered. The objective of this study was to evaluate the efficacy of full-mouth scaling (FMS) by clinical and microbiological parameters. 670 individuals were evaluated with 230 subjects meeting the selection criteria and were divided into two groups; 115 subjects treated with FMS and 115 treated with weekly sessions of scaling and root planning (SRP). The patient population had a mean age of 51.67 years, with moderate chronic periodontitis. Subjects were evaluated prior to treatment (T1) and 90 days after execution of therapy (T2), with regards to: probing depth (PD), clinical attachment level (CAL), plaque index (PI), gingival index (GI), and microbial detection for the presence of Porphyromonas gingivalis (P.g.) and Prevotella intermedia (P.i.) by culture method and confirmed by biochemical tests. Subjects treated in the FMS group also rinsed with 0.12% chlorhexidine mouthwash for seven days following treatment. The results were analyzed using statistical Student's t-test and chi-square test. No statistically significant differences were observed for PD and CAL between T1 and T2 in both groups. For GI and PI significant difference was observed between the groups. For the evaluated microbial parameters was observed reduction of P.g. and P.i., but only for P.g. with a significant reduction in both groups. The full mouth scaling technique with the methodology used in this study provided improved clinical conditions and reduction of P.g. in subjects with moderate periodontitis, optimizing the time spent in the therapeutic execution.

Resumo Na busca do tratamento ideal da doença periodontal varias são técnicas não-cirúrgicas que podem ser consideradas. O objetivo deste estudo foi avaliar a eficácia da técnica de desinfecção total de boca (FMD, na sigla em Inglês) por parâmetros clínicos e microbiológicos. Foram avaliados 670 indivíduos com 230 indivíduos atendendo aos critérios de seleção e divididos em dois grupos; 115 indivíduos tratados com FMD e 115 tratados com sessões semanais de raspagem e alisamento corono radicular (SRP, na sigla em Inglês). A população avaliada tinha idade média de 51,67 anos, com periodontite crônica moderada. Os sujeitos foram avaliados antes do tratamento (T1) e 90 dias após a execução da terapia (T2), quanto à profundidade de sondagem (PS), nível de inserção clínica (NIC), índice de placa (IP), índice gengival (IG) e detecção microbiana da presença de Porphyromonas gingivalis (P.g.) e Prevotella intermedia (P.i.) por método de cultura e confirmada por testes bioquímicos. Os indivíduos tratados no grupo FMD também realizaram bochechos com clorexidina 0,12% durante sete dias após o tratamento. Os resultados foram analisados ​​utilizando o teste estatístico t de Student e o teste de qui-quadrado. Não foram observadas diferenças estatisticamente significativas para PS e NIC entre T1 e T2 em ambos os grupos. Para IG e IP observou-se diferença significativa entre os grupos. Para os parâmetros microbianos avaliados foi observada redução de P.g. e P.i., mas apenas para P.g. com uma redução significativa em ambos os grupos. A técnica FMD com a metodologia utilizada neste estudo proporcionou condições clínicas melhoradas e redução da P.g. Em indivíduos com periodontite moderada, otimizando o tempo gasto na execução terapêutica.

The soft tissue immunologic response to hydroxyapatite-coated transmucosal implant surfaces: a study in humans.

OBJECTIVE: To evaluate the soft tissue response in humans immunologically and histologically after placement of mini-implants coated with or without nano-size hydroxyapatite coatings. MATERIAL AND METHODS: Commercially pure (cp) titanium mini-implants (n = 13) or nano-hydroxyapatite-coated ones (n = 12) were randomly placed into partially edentulous jaws. Crevicular fluid was sampled 1 week after placement and subjected to quantitative polymerase chain reaction analysis to explore the inflammatory markers. After 8 weeks, implants and surrounding soft and hard tissue were trephined, and undecalcified ground sections were prepared. Inflammatory cell accumulation within a defined region of interest in the soft tissue was quantified histomorphometrically. RESULTS: No statistically significant differences in immunological response to the different implant surfaces were found for IL-6 (p = .438), TGF-ß2 (p = .467), MMP-8 (p = .758), CCL-3 (p = .758), IL-8 (p = .771), and IL-1ß (0.771). Histomorphometric evaluation presented no statistically significant difference between the two mini-implant surfaces with regards to number of inflammatory cells (p = .669). CONCLUSION: Nano-hydroxyapatite-coated surfaces in the transmucosal region yielded similar inflammatory response and is suggested to be as biocompatible as commercially pure titanium surfaces.

The influence of 1α.25-dihydroxyvitamin d3 coating on implant osseointegration in the rabbit tibia.

OBJECTIVES: This study aims to evaluate bone response to an implant surface modified by 1α,25-dihydroxyvitamin D3 [1.25-(OH)2D3] in vivo and the potential link between 1.25-(OH) 2D3 surface concentration and bone response. MATERIAL AND METHODS: Twenty-eight implants were divided into 4 groups (1 uncoated control, 3 groups coated with 1.25-(OH)2D3 in concentrations of 10(-8), 10(-7) and 10(-6) M respectively), placed in the rabbit tibia for 6 weeks. Topographical analyses were carried out on coated and uncoated discs using interferometer and atomic-force-microscope (AFM). Twenty-eight implants were histologically observed (bone-to-implant-contact [BIC] and new-bone-area [NBA]). RESULTS: The results showed that the 1.25-(OH)2D3 coated implants presented a tendency to osseointegrate better than the non-coated surfaces, the differences were not significant (P > 0.05). CONCLUSIONS: The effect of 1.25-(OH)2D3 coating to implants suggested possible dose dependent effects, however no statistical differences could be found. It is thought that the base substrate topography (turned) could not sustain sufficient amount of 1.25-(OH)2D3 enough to present significant biologic responses. Thus, development a base substrate that can sustain 1.25-(OH)2D3 for a long period is necessary in future studies.

The influence of nano hydroxyapatite coating on osseointegration after extended healing periods.

OBJECTIVE: Studies observing early wound healing periods around dental implants demonstrate an implants ability to enhance osseointegration, the bone-implant interactions for extended healing periods though have not been thoroughly studied. METHODS: Twenty threaded titanium alloy (Ti6Al4V, Grade 5) implants were inserted bilaterally, half prepared to impart stable hydroxyapatite nanoparticles onto a sand blasted and acid etched surface (HA) and half with a non-coated control surface with only heat treatment (HT), into eighteen rabbit femurs. At 12 weeks, the bone-implant blocks were retrieved for micro computed tomography (µCT), histologic processing and histomorphometric evaluation. RESULTS: The bone-to-implant contact for the entire threaded portion of the implant revealed 57.1% (21.0) for the HT group and 38.8% (17.7) for the HA group with a total bone area within the threads 72.5% (13.9) (HT) and 59.7% (12.5) (HA). The 3D reconstructed µCT image corresponded to the histomorphometric results. SIGNIFICANCE: It is suggested that multiple factors such as the change in topography and chemistry may have influenced the outcomes.