Analysis of implant loss risk factors especially in maxillary molar location: A retrospective study of 6977 implants in Chinese individuals

Analysis of implant loss risk factors after simultaneous guided bone regeneration: A retrospective study of 5404 dental implants

PURPOSE

The purpose was to analyze the risk factors for implant loss after simultaneous guided bone regeneration (GBR).

MATERIALS AND METHODS

Patients who underwent implant placement with simultaneous GBR between January 2011 and December 2018 were screened for this study. The cumulative survival rate (CSR) was calculated using the life table method. Log-rank test and Kaplan-Meier survival estimates were used to identify potential risk factors for implant loss. The association between the investigated variables and implant loss was determined using hazard ratios (HRs) obtained from a multivariate Cox regression analysis.

RESULTS

A total of 3973 patients with 5404 implants were included in this study. The CSRs of the implants at 1, 5, and 10 years were 99.6%, 98.9%, and 98.7%, respectively. Male patient (HR = 2.94, 95% CI: 1.41-6.14), periodontitis (HR = 4.26, 95% CI: 2.05-9.86), tissue-level implants (HR = 3.02, 95% CI: 1.30-6.98), narrow implants (HR = 2.71, 95% CI: 1.12-6.57), and implant length ≤10 mm (HR = 2.91, 95% CI: 1.41-6.02) significantly increased the risk of implant loss (p < 0.05). The risk of implant loss was significantly higher in the maxillary posterior region (HR = 2.26, 95% CI: 1.04-4.90) than in the maxillary anterior region (p < 0.05). Compared to Straumann, Nobel (HR = 4.07, 95% CI: 1.75-9.44) and other implant systems (HR = 14.23, 95% CI: 4.32-46.85) showed a significantly higher risk of implant loss (p < 0.05).

CONCLUSION

Male patient, periodontitis, maxillary posterior region, Nobel implant system, other implant systems, tissue-level implants, narrow implants, and implant length ≤10 mm were considered risk factors for implant loss after simultaneous GBR.

Microbiota analysis of peri-implant mucositis in patients with periodontitis history

OBJECTIVES

To investigate the bacterial diversity in peri-implant plaques and the effect of periodontitis history on the occurrence of peri-implant mucositis.

MATERIALS AND METHODS

Three groups of subgingival plaques were collected from peri-implant sulci in the first molar area. The three groups included healthy implants in patients without periodontitis (NH implant), healthy implants in patients with periodontitis history (PH implant), and peri-implant mucositis implants in patients with periodontitis history (PM implant). Subgingival plaques in periodontal pockets of contralateral natural first molars were also collected. Bacterial DNA was extracted and the V4 region of the 16S rDNA sequence was amplified and sequenced on an Illumina HiSeq platform. The operational taxonomic units obtained from amplicon sequencing were used to analyze the prevalence and identity of bacteria based on public databases and advanced techniques.

RESULTS

Analysis of similarities indicated a significant difference in bacterial structures between the NH implant and PM implant groups. Additionally, a significantly higher relative abundance of the genera Actinomyces and Streptococcus was found in the samples of the NH implant group. The genera Fusobacterium and Prevotella could be considered as potential biomarkers for peri-implant mucositis. Moreover, more gram-negative anaerobic bacteria (Porphyromonas and Prevotella) were detected in the samples from patients with periodontitis history.

CONCLUSIONS

The increased accumulation of Fusobacterium and Prevotella is associated with a higher risk of peri-implant mucositis. In addition, patients with periodontal history may be more likely to develop peri-implant mucositis.

CLINICAL RELEVANCE

The increase in periodontal pathogens and the decrease in health-associated bacteria in patients with periodontitis history may be more likely to develop peri-implant mucositis. These results provide a bacteriological basis for the prevention and treatment of peri-implant mucositis in patients with periodontitis history.

The risk factors of early implant failure: A retrospective study of 6113 implants

BACKGROUND

The risk factors of early implant failure were controversial among previous studies, especially for implants in different sites.

PURPOSE

To analyze the rate and risk factors of early implant failure occurring before the placement of final prosthesis.

MATERIALS AND METHODS

A retrospective study was conducted based on electrical medical records of patients who received dental implant placement from 2015 to 2019. Generalized estimation equation analyses were used to explore potential risk factors influencing early implant failure.

RESULTS

Overall, 6113 implants in 3785 patients were included. The rate of early implant failure was 1.6% at patient level and 1.2% at implant level. The early implant failure was significantly associated with implants in the posterior maxilla, with specific surface modifications and in previously augmented sites (p < 0.05). Risk factors for maxillary implants included surface modification and bone augmentation procedures (p < 0.01), whereas risk factors for mandibular implants included gender and bone augmentation procedures (p < 0.05). For implants placed in previously augmented sites, implants placed in the anterior mandible had a higher risk of early failure (p < 0.05).

CONCLUSIONS

The risk factors for early implant failures varied among different sites; hence, they should be comprehensively considered in presurgical treatment plan.

Surface Modified Techniques and Emerging Functional Coating of Dental Implants

Dental implants are widely used in the field of oral restoration, but there are still problems leading to implant failures in clinical application, such as failed osseointegration, marginal bone resorption, and peri-implantitis, which restrict the success rate of dental implants and patient satisfaction. Poor osseointegration and bacterial infection are the most essential reasons resulting in implant failure. To improve the clinical outcomes of implants, many scholars devoted to modifying the surface of implants, especially to preparing different physical and chemical modifications to improve the osseointegration between alveolar bone and implant surface. Besides, the bioactive-coatings to promote the adhesion and colonization of ossteointegration-related proteins and cells also aim to improve the osseointegration. Meanwhile, improving the anti-bacterial performance of the implant surface can obstruct the adhesion and activity of bacteria, avoiding the occurrence of inflammation related to implants. Therefore, this review comprehensively investigates and summarizes the modifying or coating methods of implant surfaces, and analyzes the ossteointegration ability and anti-bacterial characteristics of emerging functional coatings in published references.

Alveolar Bone Density and Width Affect Primary Implant Stability

Primary implant stability (PIS) depends on surgical technique, implant design, and recipient bone characteristics, among other factors. Bone density (BD) can be determined in Hounsfield units (HUs) using cone beam computerized tomography (CBCT). Reliable prediction of PIS could guide treatment decisions. We assessed whether PIS was associated with recipient bone characteristics, namely, BD and alveolar ridge width (ARW), measured preoperatively by CBCT. We studied a convenience sample of 160 implants placed in 48 patients in 2016 and 2017. All underwent CBCT with a radiologic/surgical guide yielding values for ARW and BD. PIS measures used were the implant stability quotient (ISQ) from resonance frequency analysis and insertion torque (IT). IT was most influenced by the HU value at 0.5 mm outside the implant placement area, followed by the value within this area, and ISQ by the HU value at 0.5 mm outside the placement area, followed by implant placement site and apical ARW. ISQ values were significantly related to ARW in coronal (P < .05), middle (P < .01), and apical (P < .01) thirds. ISQs were higher with larger-diameter implants (P < .01). ISQ and IT were strongly correlated (P < .001). PIS in terms of ISQ and IT is positively correlated with edentulous alveolar ridge BD measured by CBCT, implying that implant stability may be predicted preoperatively. Wide alveolar ridges favored lateral PIS but did not affect rotational PIS. The most significant predictor of lateral and rotational PIS in our patients was the HU value at 0.5 mm outside the implant placement area.

Retrospective clinical analysis of risk factors associated with failed short implants

BACKGROUND

With advanced technology, short implants are more commonly used and have proven to have a relatively reliable curable efficacy. A consensus has not been reached regarding potential risk factors related to the loss of short implants.

PURPOSE

This large-sample retrospective study concentrated not only on patient characteristics and medical procedures but also on the features of implants in order to uncover the risk factors associated with short implants.

METHODS

Between 2014 and 2017, a total of 7001 implants were inserted at Nanjing Stomatological Hospital, Medical School of Nanjing University. Among the all, 1236 short implants were included after being evaluated according to the inclusion and exclusion criteria. In organizing the detailed information, seven variables including bone grafting procedure, age, gender, diameter of the implant, implant position, surface treatment, and definitive restorations were taken into consideration. The χ² test, Kaplan-Meier test, logistic regression, and multifactorial Cox regression analysis were employed to explore the risk factors.

RESULTS

The cumulative survival rate of short implants was 96.36%, slightly lower than that of the standard implants (98.16%, P < .001). Most of the short implants (84.44%) were lost at the early stage, mainly because of infection. Based on the results, male gender, implants treated by titanium anodizing and single-crown restoration increased the loss rate of short implants. Comparison of the short implants inserted into the maxillary and mandibular posterior area alone showed that the maxillary molar area was a risk factor for prognosis.

CONCLUSIONS

Male gender, TA surface treatment, and the presence of a single crown were associated with an increasing rate of short implants loss. Examination of the implant location focused on the posterior area revealed the maxillary posterior area to be a risk factor.

Satisfaction analysis of patients with single implant treatments based on a questionnaire survey

Background: The factors influencing satisfaction of the patients with implant treatments are still unclear. This study aims to evaluate the patients' satisfaction and to identify influencing factors, which will improve the medical quality of oral implantology. Materials and methods: Patients who lost single teeth and received implant treatments were enrolled in Nanjing Stomatological Hospital between February 2016 and March 2018. A questionnaire survey was performed to assess patient satisfaction and data were collected at four time points. Information included gender, age, educational level, application of bone augmentation, type of prosthetic restoration, period of teeth loss, dentist qualification, and tooth position. Meanwhile, the satisfaction of the patients was evaluated by visual analog scale. Results: A total of 373 patients completed the questionnaires. The mean of overall satisfaction score was 69.05±7.10. Lower overall satisfaction score was found in patients who received bone augmentation (P<0.001) and those with a longer period of teeth loss (P<0.05). In the bone augmentation group, the elements of pain and complication were significantly associated with a decrease in the median satisfaction score (P<0.001), and a similar result was obtained form the duration of operative time and healing response (P<0.001). On the other hand, the satisfaction scores for elements including the duration of operative time and healing response (P<0.05), aesthetics and psychology (P<0.05), and chewing function (P<0.05) decreased with an extended period of teeth loss. Meanwhile, over half of respondents were more concerned about the survival time (40.70%) and success rate (20.49%) of implants. Conclusion: Bone augmentation and the period of teeth loss are negative factors affecting patient satisfaction, and the success rate and survival time of implants are considerable aspects for patients. It is essential to raise general awareness of oral hygiene and optimize the dental implant therapeutic process.