Comparison of long-term survival of implants and endodontically treated teeth

Digital-assisted diagnosis and orthodontic management of an impacted mandibular lateral incisor: a case report

BACKGROUND

The impaction of mandibular lateral incisors presents significant aesthetic and functional challenges in orthodontics, including Bolton ratio discrepancies and anterior occlusal anomalies. The increasing preference for nonextraction treatment further complicates space management within the dental arch. However, the advent of digital-assisted orthodontic technologies, particularly advanced digital simulations, has revolutionized the precision and effectiveness of diagnosis and treatment planning. These technologies enable clinicians to strategically leverage natural jaw development and create the necessary space for the alignment of impacted teeth without resorting to extraction.

CASE PRESENTATION

This case report details the treatment of a 12-year-old male with an impacted mandibular lateral incisor, which resulted in both aesthetic concerns and functional impairments, alongside Class II malocclusion. By employing a digital-assisted diagnostic approach, including comprehensive digital simulations, we meticulously evaluated the feasibility of a nonextraction treatment plan. The strategy centred on harnessing the patient's mandibular growth potential to expand the available space naturally. The treatment involved surgical exposure of the impacted tooth, followed by precise orthodontic traction guided by continuous digital monitoring. The integration of digital tools throughout the treatment process was crucial in achieving successful eruption and alignment of the impacted tooth, thus restoring optimal aesthetics and function without the need for extraction.

CONCLUSION

This case highlights the transformative impact of digital-assisted technologies in the management of complex orthodontic cases, such as impacted mandibular lateral incisors. The successful integration of these advanced tools with a nonextraction treatment approach underscores their potential to significantly enhance clinical outcomes. Digital technologies not only improve the accuracy and effectiveness of treatment but also facilitate a multidisciplinary approach that elevates the standard of patient care in addressing complex orthodontic challenges.

Effect of osteopenia and osteoporosis on failure of first and second dental implants: a retrospective observational study

PURPOSE

The present study evaluated osteopenia (OPN) and osteoporosis (OP) as risk factors for dental implant failure and repeat failure.

METHODS

We performed a retrospective study on over 100 randomly selected patients per analysis to determine the effect of health status, smoking status, sex, implant location and operative conditions on first and second (re-implantation) implant survival. Analyses were conducted first using chi-squared test, followed by multiple logistic regression for significant variables.

RESULTS

In the cohort examining the effect of myriad risk factors on second implant survival, it was found that OPN and OP greatly impacted implant survival, wherein patients with osteoporosis or osteopenia had significantly more implant failures (p = 0.0353). Sex and operative conditions had no effect on implant survival, while implant location showed a notable effect wherein significantly more failures occurred in the maxilla vs mandible (p = 0.0299). Upon finding that OPN and OP have a significant effect on second implant survival, we conducted an additional study focusing on the impact of health status. Based on the multiple logistical regression analysis, we found that OPN and OP are the most significant factor in first implant survival (p = 0.0065), followed by diabetes (p = 0.0297). Importantly, it was observed that early implant failure is also significantly correlated with osteoporosis (p = 0.0044).

CONCLUSION

We show here a marked relationship in which the risk of first and second implant failure are significantly higher in patients with osteoporosis and osteopenia.

The role of the general dental practitioner in the care of the implant patient

Introducing dental implants into a patient's oral health plan requires a collaborative effort between all members of the care team, including the "implant dentist" and referring general dental practitioner (GDP), should the treatment be carried out in a referral practice. This article aims to discuss the pivotal role referring general dental practitioners (GDPs) play in preparing patients for dental implant placement, whatever the setting for the planned treatment. An overview of the patient referral process is outlined, as is the role of GDPs in the ongoing maintenance of the dental implants and the patient's oral health. Furthermore, this article may be viewed as a road map for GDPs who refer patients to an "implant dentist" as part of their treatment plan.

Survival of endodontically treated teeth in public dental service in Northern Finland: a practise-based register study

OBJECTIVE

The aim of this study was to explore the factors associated with the survival of root canal treated teeth in a practise-based study setting in a 5-year period.

MATERIAL AND METHODS

This retrospective study used data from the electronic patient registration system of the public dental services of the City of Oulu, Finland. The inclusion criteria for this study were patients aged ≥ 20 years who had root canal treatment (RCT) that was initiated in 2014. One RCT per patient was included in the study. A total of 713 patients met the inclusion criteria. The outcome variable for this study was the extraction of the RCT tooth during the 5-year period. Explanatory variables included age, diagnosis, tooth type (incisive, canine, premolar, molar), RCT technique (manual, motorized), time from RCT initiation to final restoration and type of final restoration (composite, glass ionomer, fixed dental prosthesis). To evaluate the association between the outcome variable and explanatory variables, Cox regression analyses were performed.

RESULTS

The overall survival rate was 91%. The middle-aged (40-59-years-old) and the oldest (60 and older) patients had a two-fold risk of extraction compared to younger (20-40-years-old) patients. Similarly, a short length of time from RCT initiation to final restoration (0-14 days) resulted in a nearly three times higher risk of extraction compared to a longer period (≥ 90 days).

CONCLUSIONS

The 5-year survival rate of RCTs seems high. Extractions were more common among patients over 40 years of age and if the RCT was completed shortly after its initiation.

Forensic exploration of endodontic cements: Unveiling macroscopic and radiographic changes under high temperatures

OBJECTIVE

To evaluate macroscopically and radiographically the behavior of four endodontic sealers submitted to high temperatures, with forensic purposes.

METHODS

Sixty-four lower anterior teeth were included. All teeth were endodontically treated, and simulation of external cervical resorption (ECR) was performed. Half of the sample was filled with AH-Plus™ cement and had ECR sealed with Bio-C-Repair™. The other 32 teeth were filled with Bio-C-Sealer™ cement and had their respective ECR sealed with MTA-Repair™. Then, all teeth were introduced into a bovine bone block to simulate the alveolar bone. The teeth were submitted to incineration at temperatures of 600, 800, 1000, and 1140 °C. All teeth were radiographed before and after incineration. The pre-and post-incineration radiopacity of cements and dentin were evaluated using the ImageJ™ software and compared using a t-test for paired samples.

RESULTS

It was possible to confirm color change and appearance of cracks in the tissues and dental materials tested, varying according to the temperature. Radiographically, it was observed that the dental crowns completely detached at 1000 ° and 1140 °C, and, only at 1140 °C, the roots showed cracks. Regarding the radiopacity, there was a significant difference in the shades of gray in AH-Plus™ when subjected to 1000 ° and 1140 °C, and at 600 ° and 1000 °C in Bio-C-Sealer™. In Bio-C-Repair™ and MTA-Repair™, a difference was observed at 600 ° and 1140 °C.

CONCLUSIONS

There were macroscopic and radiographic alterations of the materials. This data is important in Forensic Dentistry and may contribute to identifying carbonized victims.

Risk factors associated with the survival of endodontically treated teeth: A retrospective chart review

BACKGROUND

Studies on risk factors affecting tooth retention after endodontic treatment in dental school settings are limited. Understanding these factors is crucial for preserving teeth. The aim of this retrospective study was to evaluate patient- and tooth-level risk factors associated with the survival of endodontically treated teeth.

METHODS

Electronic health records of patients who underwent endodontic treatment at the School of Dental Medicine at the University of Pennsylvania from 2017 through 2020 were analyzed. Patient-level factors included age, sex, American Society of Anesthesiologists Physical Status Classification, smoking history, diabetes status, and amoxicillin allergy. Tooth-level factors included position, presence of restorations, and periodontal conditions with preprosthetic treatments.

RESULTS

The results of this study indicate that the patient-level factors significantly associated with tooth retention included age, sex, American Society of Anesthesiologists Physical Classification Status, and amoxicillin allergy. Tooth-level factors such as core buildup, full-coverage crown, healthy periodontium, and scaling and root planing were also associated with higher survival rates. Mandibular premolars had higher survival rates than mandibular molars.

CONCLUSIONS

This investigation revealed that the tooth retention rate of endodontically treated teeth was 96.2% after initial root canal treatment, 92.4% for nonsurgical re-treatment, and 97.8% for surgical re-treatment.

PRACTICAL IMPLICATIONS

The tooth retention of the endodontic treatment was associated with healthy periodontium, tooth structure, tooth position, tooth restoration, and the patient's overall health.

Effectiveness of intentional replantation in managing teeth with apical periodontitis: A systematic review

BACKGROUND

Intentional replantation (IR) to treat disease of endodontic origin remains controversial. While IR has been advocated by some clinicians as another valid treatment option, others consider it as a treatment procedure of last resort.

OBJECTIVE

To systematically review and critically evaluate the effectiveness of IR compared with nonsurgical root canal treatment/retreatment or apical surgery in terms of clinical and patient-related outcomes in managing permanent teeth with apical periodontitis (AP).

METHODS

A literature search of five databases (PubMed, Embase, Scopus, Web of Science and Cochrane Central register of Controlled Trials), and the grey literature (Networked Digital Library of Theses and Dissertations, Open Access Theses and Dissertations, DART-Europe E-theses Portal, British Library E-Theses Online Service), from inception to November 2021, was conducted. Randomised clinical trials, comparative clinical trials (CCTs), nonrandomised, retrospective, and prospective comparative cohort and case-control two arm studies which evaluated clinical and/or patient-related outcomes of permanent teeth with AP treated with IR compared with nonsurgical root canal treatment/retreatment or apical surgery were identified. The quality of the studies was appraised using the Cochrane risk of bias tool for randomized trials (RoB 2.0), the Robins-I for nonrandomized controlled clinical trials and the Newcastle-Ottawa scale for observational studies. Two independent reviewers were involved in the literature selection, performed the data extraction and the appraisal of the studies identified; disagreements were resolved in conjunction with a third reviewer.

RESULTS

No comparative study was identified from the literature search. Four longitudinal studies (one prospective and three retrospective) were identified during the screening of titles and abstracts but were excluded after reading the full text, because only IR was evaluated (single arm studies).

DISCUSSION

The available evidence on IR is mainly based on observational studies, which reported high overall mid- to long-term survival, and low complication rates. The results suggest that IR may represent an alternative treatment procedure to solve problems of endodontic origin. However, in the absence of high-quality evidence from CCTs, clinical decision-making should be on a case-by-case basis and in accordance with the clinician's experience and the patient's preference.

CONCLUSION

Clinical studies showed that IR may be a treatment modality to manage problems of endodontic origin. However, clinical trials comparing the effectiveness of IR with nonsurgical root canal treatment/retreatment or apical surgery are still required given the paucity of evidence.

Use of Systemic Steroids, Hormone Replacement Therapy, or Oral Contraceptives Is Associated with Decreased Implant Survival in Women

BACKGROUND

Systemic steroids, such as prednisone, hormonal replacement therapies, or oral contraceptives, are commonly prescribed to women who might also be receiving dental implant therapy. However, the effect of these medications on dental implant survival is unknown.

METHODS

The medical and dental records of individuals with dental implants (N = 1480 implants) who visited a postgraduate periodontics clinic between 2000 and 2017 were initially considered. Those younger than 21 years old, pregnant, or male were excluded according to the study's exclusion criteria. The presence of systemic diseases and conditions was assessed. Implant failure rates among female patients using systemic steroids, hormone replacement therapy, or oral contraceptives were compared with failure rates among patients not taking those medications.

RESULTS

The implant failure rate for the 65 implants in patients taking steroid medications was 7.69%; the failure rate for the 712 implants in patients not taking steroids was 1.54% (p < 0.001). After adjusting for smoking and the presence of diabetes, that relationship persisted, with an 8.47% implant failure rate for the 59 implants in patients taking steroids (vs. 1.54% failure for the 585 implants in patients not taking steroids; p < 0.001). Regression analyses demonstrated that the odds of implant failure versus success were 5.31 times greater in patients taking systemic steroids, hormone replacement therapy, or oral contraceptives (p < 0.05). No statistically significant differences in patient plaque control were found between the experimental and control groups.

CONCLUSIONS

Among women, the use of systemic steroids is associated with a five-fold increase in the rate of dental implant failure, regardless of the presence of smoking or diabetes.

Comparing the Long-Term Success Rates of Tooth Preservation and Dental Implants: A Critical Review

Implant therapy is considered a predictable, safe, and reliable rehabilitation method for edentulous patients in most clinical scenarios. Thus, there is a growing trend in the indications for implants, which seems attributable not only to their clinical success but also to arguments such as a more "simplified approach" based on convenience or the belief that dental implants are as good as natural teeth. Therefore, the objective of this critical literature review of observational studies was to discuss the evidence concerning the long-term survival rates and treatment outcomes, comparing endodontically or periodontally treated teeth with dental implants. Altogether, the evidence suggests that the decision between keeping a tooth or replacing it with an implant should carefully consider the condition of the tooth (e.g., amount of remaining tooth and degree of attachment loss and mobility), systemic disorders, and patient preference. Although observational studies revealed high success rates and long-term survival of dental implants, failures and complications are common. For this reason, attempts should be made to first save maintainable teeth over the long-term, instead of immediately replacing teeth with dental implants.

The importance of establishing a core outcome set for endodontic clinical trials and outcomes studies

Endodontic therapy aims to preserve teeth by preventing and treating apical disease, therefore, evaluation of treatment outcome in clinical trials and outcomes studies should effectively assess if it achieves these aims. Traditionally, treatment outcomes have been reported by clinicians after history and clinical examination in what is known as clinician-reported outcomes (CROs). Much less commonly employed however, are patient-reported outcomes (PROs) in which patients directly report on their condition. Endodontic treatment outcome reporting is evolving from a focus on CROs to increasing consideration for patient and disease-focused outcomes, with different criteria being proposed for assessment of treatment outcomes. Unfortunately, this has led to considerable variability and a lack of consensus on the definition, appropriate measurement and reporting of these outcomes. Heterogeneity in outcome reporting in clinical research provides a significant major barrier to conduct meta-analysis, guidelines development, clinical decision making, and ultimately affecting patient care. These effects could, however, be reduced by the establishment of a core outcome set (COS) in endodontics, which is defined as an agreed, standardized set of outcomes that should be included, measured and reported as a minimum in all trials and outcome studies. COS development is a regulated and validated process requiring involvement of appropriate stakeholders as well as a rigorous methodology. To date, COS has been developed for the management of traumatic dental injuries, orthodontic and periodontal treatment and is currently being developed for endodontic treatment. The aim of this review is to discuss the importance of COS in endodontics with focus on the evidence for and impact of heterogeneity in reporting endodontic treatment outcomes. An overview of an ongoing process for development of COS for different endodontic treatment modalities will also be provided.

Effects of TiS2 on Inhibiting Candida albicans Biofilm Formation and Its Compatibility with Human Gingival Fibroblasts in Titanium Implants

Titanium is widely used in medical devices, such as dental and orthopedic implants, due to its excellent mechanical properties, low toxicity, and biocompatibility. However, the titanium surface has the risk of microbial biofilm formation, which results in infections from species such as Candida albicans (C. albicans). This kind of biofilm prevents antifungal therapy and complicates the treatment of infectious diseases associated with implanted devices. It is critical to developing a feasible surface to decrease microbial growth while not interfering with the growth of the host cells. This study reports the influence of titanium surface modification to titanium disulfide (TiS₂) on inhibiting C. albicans biofilm formation while allowing the attachment of human gingival fibroblasts (HGFs) on their surface. The surface of titanium parts is directly converted to structured titanium and TiS₂ using direct laser processing and crystal growth methods. C. albicans adhesion and colonization are then investigated on these surfaces by the colony counting assay and reactive oxygen species (ROS) assay, using 2',7'-dichlorofluorescin diacetate (DCFH-DA) and microscopy images. Also, the viability and adhesion of HGFs on these surfaces are investigated to show their adhesion and biocompatibility. Titanium samples with the TiS₂ surface show both C. albicans biofilm inhibition and HGF attachment. This study provides insight into designing and manufacturing titanium biomedical implants.

Post-Fatigue Fracture Resistance of Lithium Disilicate and Polymer-Infiltrated Ceramic Network Indirect Restorations over Endodontically-Treated Molars with Different Preparation Designs: An In-Vitro Study

The aim of the present study was to evaluate the fatigue to cyclic and static resistance of indirect restorations with different preparation designs made either of lithium disilicate (LS) or polymer-infiltrated ceramic network (PICN). Eighty-four (n = 84) molars were chosen, endodontically treated, and prepared with standardized MOD cavities. The molars were randomly divided into 6 study groups (n = 14) taking into account the "preparation design'' (occlusal veneer with 1.2 mm occlusal thickness; overlay with 1.6 mm occlusal thickness; adhesive crown with 2 mm occlusal thickness) and the "CAD/CAM material'' (E-max CAD, Ivoclar vivadent; Vita Enamic, Vita). A fatigue test was conducted with a chewing simulator set at 50 N for 1,500,000 cycles. Fracture resistance was assessed using a universal testing machine with a 6 mm diameter steel sphere applied to the specimens at a constant speed of 1 mm/min. A SEM analysis before the fracture test was performed to visually analyze the tooth-restoration margins. A statistical analysis was performed with a two-way ANOVA and a post-hoc pairwise comparison was performed using the Tukey test. The two-way ANOVA test showed that both the preparation design factor (p = 0.0429) and the CAD/CAM material factor (p = 0.0002) had a significant influence on the fracture resistance of the adhesive indirect restorations. The interaction between the two variables did not show any significance (p = 0.8218). The occlusal veneer had a lower fracture resistance than the adhesive crown (p = 0.042) but not lower than the overlay preparation (p = 0.095). LS was more resistant than PICN (p = 0.002). In conclusion, in the case of endodontically treated teeth, overlay preparation seems to be a valid alternative to the traditional full crown preparation, while occlusal veneers should be avoided in restoring non-vital molars with a high loss of residual tooth structure. LS material is more resistant compared to PICN.

Impact of maxillofacial growth on implants placed in adults: A narrative review

OBJECTIVE

To determine the effect of lifetime maxillofacial changes on dental implants placed in adults, analyze the clinical implications of these changes, identify prognostic factors, and offer possible solutions.

OVERVIEW

The relationship between implant placement and maxillofacial changes, occurring during not only the active growth period but also the entire span of adulthood, has not been extensively examined. Vertical differences between implants and adjacent teeth due to the ankylotic behavior of the former might be observed at any age and endanger restoration biologically, functionally, and esthetically. Regarding interproximal contacts, firm contact loss may occur within a few months after restoration, resulting in food impaction. Many prognostic factors have been reported, but most do not exhibit a statistically significant association with implant infraocclusion and interproximal contact loss. Incorporation of alternative solutions, accurate treatment planning, strict recall protocols, and retrievability of implant-supported restorations can facilitate efficient management of complications.

CONCLUSION

Maxillomandibular changes throughout adulthood may lead to complications such as implant infraocclusion and interproximal contact loss. Rehabilitation of edentulism should be characterized by well-designed and flexible treatment plans to resolve long-term complications efficiently. Further long-term clinical studies are needed to identify other risk factors.

CLINICAL SIGNIFICANCE

Treatment plans for implant therapy should be reconsidered for adults. Careful patient monitoring and early intervention are essential for securing treatment outcomes.

Outcomes of Primary Root Canal Therapy: An updated Systematic Review of Longitudinal Clinical Studies Published between 2003 and 2020

Background

A comprehensive effort to evaluate outcomes of primary root canal therapy (RCT) between 1966 and 2002 was published by Ng et al. (2007, International Endodontic Journal, 40, 921; 2008, International Endodontic Journal, 41, 6). Changes in endodontic materials and treatment methods warrant an updated analysis of outcomes.

Objectives

This study aimed to (1) quantify the success rates of primary RCT published between 2003 and 2020; and (2) investigate the influence of some characteristics known/suspected to be associated with treatment outcomes.

Methods

An electronic search was performed in the following databases (01‐01‐2003 to 12‐31‐2020): Pubmed, Embase, CINHAL, Cochrane and Web of Science. Included study designs were longitudinal clinical studies (randomized control trials, cohort studies, retrospective observational studies). Studies with at least twelve‐months of post‐operative review and success rates based on clinical and radiographic criteria were analysed. The terms ‘strict’ (complete resolution of periapical lesion) or ‘loose’ (reduction in size of existing periapical lesion) were used to describe the outcome criteria. Weighted, pooled success rates were calculated. Random effects meta‐regression models were used to investigate potential sources of statistical heterogeneity. The Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach was used to evaluate for quality assessment of the included studies.

Results

Forty‐two studies were included in the review. Meta‐analyses showed that the weighted pooled success rates were estimated to be 92.6% (95% CI: 90.5%–94.8%) under ‘loose criteria’ and 82.0% (95% CI: 79.3%–84.8%) under ‘strict’ criteria. The most significant areas of study heterogeneity were year of publication and qualification of operator. The majority (64.29%) of studies were considered to be of low quality of evidence.

Discussion

Biological factors continue to have the most significant impact on RCT outcomes. The technological method of instrumentation had no significant effect. The quality of evidence was based primarily on study design and only randomized control trials were considered to be ‘high’ quality of evidence.

Conclusions

The reported success rates show improvement over time. Weighted success rates for studies with a minimum of four‐years follow‐up had better outcomes, compared to those with less than four years, when ‘strict criteria’ were used.

Registration

PROSPERO database (CRD42021226311).

Regenerative Endodontics Success Factors and their Overall Effectiveness: An Umbrella Review

Introduction

Regenerative endodontics is a developing field of dentistry and aims to recover the physiological and anatomical functions of the tooth for cases of severe dental caries, pulpal pathologies and dental trauma.

Materials and Methods

This umbrella review seeks to discover the scientific evidence on the effectiveness and the factors result in successful regenerative endodontic therapies in teeth with necrotic pulps and with incomplete root development. The study was conducted following the PRISMA Guidelines. There were no restrictions regarding search period. A comprehensive literature search was carried out in EMBASE, LILACS, PubMed, Cochrane, Scopus, and Google Scholar. A quality evaluation was conducted by using AMSTAR-2. A descriptive analysis of the included systematic reviews and meta-analysis were conducted.

Results

Thirteen descriptive systematic reviews and 7 meta-analyses were included. Three articles evidenced low methodological quality according to AMSTAR-2 tool. Overall success rates for the endodontic regeneration procedures ranged from 50% to 98% and the survival rates were between 94% and 100%. Pulp regeneration had a high success rate, evidenced by factors such as the resolution of symptoms, healing, increased root length, dentin thickening and recovery of sensitivity. Follow-up varied from 1 to 48 months for the original studies included in the systematic reviews and meta-analyses.

Conclusions

Endodontic practice offers the clinician a good treatment option in case of necrotic pulp with immature roots such as the endodontic regeneration, that is supported by high and moderate quality scientific literature.

Success rate of nitrous oxide-oxygen procedural sedation in dental patients: systematic review and meta-analysis

The aim of this systematic review was to determine the success rate of nitrous oxide-oxygen procedural sedation (NOIS) in dentistry. A systematic digital search was conducted for publications or reports of randomized controlled trials evaluating the clinical performance of NOIS. Abstracts of research papers were screened for suitability, and full-text articles were obtained for those who met the inclusion and exclusion criteria accordingly. The quality of the studies was assessed using the revised Cochrane risk-of-bias tool (RoB 2). A total of 19 articles (eight randomized clinical trials with parallel intervention groups and 11 crossover trials), published between May 1988 and August 2019, were finally selected for this review. The studies followed 1293 patients reporting NOIS success rates, with a cumulative mean value of 94.9% (95% CI: 88.8–98.9%). Thirteen trials were conducted on pediatric populations (1098 patients), and the remaining six were conducted on adults (195 patients), with cumulative efficacy rates of 91.9% (95% CI: 82.5–98.1%) and 99.9% (95% CI: 97.7–100.0%), respectively. The difference was statistically significant (P = 0.002). Completion of treatment and Section IV of the Houpt scale were the most used efficacy criteria. Within the limitations of this systematic review, the present study provides important information on the efficacy rate of NOIS. However, further well-designed and well-documented clinical trials are required and there is a need to develop guidelines for standardization of criteria and definition of success in procedural sedation. Currently, completion of treatment is the most used parameter in clinical practice, though many others also do exist at the same time. To maximize NOIS efficacy, clinicians should strictly consider appropriate indications for the procedure.

Applications of Finite Element in Implant Dentistry and Oral Rehabilitation

Finite element is widely applied in dentistry to study the stress distributions on adjoining bone, the biomechanics of dental implant and bone; implant and bone interface and study its fatigue behaviors of the implant. This article presents various applications of finite element in implant dentistry. Available articles were searched and reviewed from March 1980 till September 2020 from Pubmed, Scopus, Google Scholar, and Science direct. Relevant studies were included and critically analyzed. Finite element is an important tool in implant dentistry to study the stress distributions on adjoining bone, the biomechanics of dental implant and bone; implant and bone interface, and fatigue behaviors.

Role of Stem Cells in Augmenting Dental Implant Osseointegration: A Systematic Review

Dental implants are a widely used treatment modality for oral rehabilitation. Implant failures can be a result of many factors, with poor osseointegration being the main culprit. The present systematic review aimed to assess the effect of stem cells on the osseointegration of dental implants. An electronic search of the MEDLINE, LILACS, and EMBASE databases was conducted. We examined quantitative preclinical studies that reported on the effect of mesenchymal stem cells on bone healing after implant insertion. Eighteen studies that fulfilled the inclusion criteria were included. Various surface modification strategies, sites of placement, and cell origins were analyzed. The majority of the selected studies showed a high risk of bias, indicating that caution must be exercised in their interpretation. All the included studies reported that the stem cells used with graft material and scaffolds promoted osseointegration with higher levels of new bone formation. The mesenchymal cells attached to the implant surface facilitated the expression of bio-functionalized biomaterial surfaces, to boost bone formation and osseointegration at the bone–implant interfaces. There was a promotion of osteogenic differentiation of human mesenchymal cells and osseointegration of biomaterial implants, both in vitro and in vivo. These results highlight the significance of biomodified implant surfaces that can enhance osseointegration. These innovations can improve the stability and success rate of the implants used for oral rehabilitation.

Factors Associated with Extraction following Root Canal Filling in Adults

Essentially, root fillings are performed to preserve natural teeth. Over time, however, some root-filled teeth will inevitably be extracted. The aim of this historical prospective cohort study in the adult Swedish population was to identify factors associated with extractions within 5 y of registration of a root filling. The cohort consisted of all those whose root fillings had been reported to the tax-funded Swedish Social Insurance Agency (SSIA) in 2009. Demographic data on the individuals registered with a root filling (sex, age, country of birth, disposable income, educational level, and marital status) were received from Statistics Sweden or the SSIA. Dental care setting, tooth type, and any registration of subsequent restorations within 6 mo were received from the SSIA. Multivariable regression analysis was used, and P < 0.05 was considered statistically significant. In total, 216,764 individuals had been registered with at least 1 root filling. Individuals (n = 824) without complete data were excluded from the analyses. After 5 y, 9.3% of the root-filled teeth had been registered as extracted. Logistic regression analysis found significant associations for all variables except country of birth, disposable income, and educational level. The highest odds ratios for extractions were associated with the type of restoration: teeth with no registration of any restoration and teeth with a direct restoration combined with a post were 3 times more likely to undergo extraction than teeth restored with an indirect restoration combined with a post and core. Overall, high odds ratios for extractions were associated with any type of composite restoration, including composite fillings and crowns combined with or without any post. In summary, after root filling in the Swedish adult population, several individual- and tooth-specific variables were associated with extraction. The reasons for the extractions remain to be studied further.

Analysis of Prosthetic Factors Affecting Peri-Implant Health: An in vivo Retrospective Study

Objective

To investigate and compare the various restorative and prosthetic parameters affecting peri-implant tissues’ health following dental implant placement and functional loading.

Methods

A total of 484 dental implants (length>6mm, non-turned, 2–3 piece, titanium – Straumann) were evaluated for patients (male=271; female=213). Study variables such as patient’s age, gender, implant restoration/crown type, crown retention, and implant crown status were assessed against various periodontal parameters (periodontal pocket depth (PPD), plaque index (PI), bleeding on probing (BOP), gingival color, and crestal bone level). All the data were analyzed using the SPSS software.

Results

Out of all the investigated dental implants, 201 (42%) of the implants investigated presented with BOP > one-site of the peri-implant mucosa (peri-implant mucositis), 115 (23.76%) presented with peri-implant marginal bone loss. PPD value was significantly lower in good crown status (p<0.0001). Majority of the patients with good crown status had no plaque accumulation based on the PI scores (52.7%). Only 35% of the patients whose crown status was good were having BOP when compared with 65% who did not have any BOP recorded. Gingival color (pale pink and red) showed statistically significant association with crown type (porcelain fused to metal v/s all ceramic) (p=0.005). Most of patients with crown status good had no change in their radiographic findings (94%) compared to only 6% who had implant threads exposed (p<0.0001).

Conclusion

Optimal design of Implant prosthetic factors are vital for avoiding the development of peri-implant mucositis/peri-implantitis and must be considered during treatment planning while restoring dental implants.

The restoration of root filled teeth: a review of the clinical literature

Clinicians often face dilemmas regarding the most appropriate way to restore a tooth following root canal treatment. Whilst there is established consensus on the importance of the ferrule effect on the predictable restoration of root filled teeth, other factors, such as residual tooth volume, tooth location, number of proximal contacts, timing of the definitive restoration and the presence of cracks, have been reported to influence restoration and tooth survival. The continued evolution of dental materials and techniques, combined with a trend towards more conservative endodontic-restorative procedures, prompts re-evaluation of the scientific literature. The aim of this literature review was to provide an updated overview of the existing clinical literature relating to the restoration of root filled teeth. An electronic literature search of the PubMed, Ovid (via EMBASE) and MEDLINE (via EMBASE) databases up to July 2020 was performed to identify articles that related the survival of root filled teeth and/or restoration type. The following and other terms were searched: restoration, crown, onlay, root canal, root filled, post, clinical, survival, success. Wherever possible, only clinical studies were selected for the literature review. Full texts of the identified articles were independently screened by two reviewers according to pre-defined criteria. This review identifies the main clinical factors influencing the survival of teeth and restorations following root canal treatment in vivo and discusses the data related to specific restoration type on clinical survival.

Shared Decision Making in Endodontics

Engaging patients in shared decision making (SDM) is a professional requirement since the Montgomery ruling in 2015. Endodontic treatments present a specific challenge to achieving SDM, both for the clinician and the patient. The treatments are often perceived as more challenging to complete by the clinician, and the assessment of risk and likely outcome requires a deep understanding of the (limited) evidence base. For the patient, decisions can be required at a time of acute symptoms and prolonged treatments. There are health literacy demands in comparison to some less complex dental treatments. Treatment decisions may be based more on inherent biases and prior experiences than objective probabilities. This article discusses options and supports effective shared decision making in endodontic treatment.

Treatment of an Endo-Perio Lesion with Ozone Gas in a Patient with Aggressive Periodontitis: A Clinical Case Report and Literature Review

The pulp and periodontium have obvious relationships that have been described in many studies. Pulp infections may affect periodontal tissues and vice versa. Teeth with endo-perio lesions have a worse prognosis than isolated endodontic or periodontal lesions. Elimination of endodontic and periodontal infections is essential for successful treatment, so co-operation between endodontists and periodontists is necessary. In this clinical case, a 44-year-old male presented with primary periodontal disease with secondary endodontic involvement in his lower right canine because of aggressive periodontitis. There was 10 mm of clinical attachment loss and 8 mm periodontal pocket mesial from the tooth and bone radiolucency periapical and lateral from the root. Periodontal therapy was followed by endodontic treatment. Periodontal therapy included root scaling and planing, treatment of the periodontal pocket with ozone gas, systemic antibiotics, oral hygiene instructions, and chlorhexidine rinsing. Endodontic therapy included root canal instrumentation with rotary endodontic files, irrigation, root canal treatment with ozone gas, and obturation with lateral compaction. Radiographs at a 6-month follow-up appointment showed complete healing of the periapical lesion and alveolar bone lateral to the root. Using an interdisciplinary approach to treat endo-perio lesions provides favorable clinical outcomes. Ozone therapy is beneficial for the successful treatment of endo-perio lesions with narrow periodontal pockets in patients with aggressive periodontitis and poor prognosis.

German Dentists' Preferences for the Treatment of Apical Periodontitis: A Cross-Sectional Survey

Currently, there is no standard treatment protocol for apical periodontitis (AP). Thus, restorable teeth might get extracted and replaced prosthetically. This study evaluated German dentists’ preferred AP treatment decisions and the influencing factors for selecting tooth retention by initial/repeated surgical/non-surgical root-canal treatment (RCT) or extraction with/without prosthetic replacement. Through an online-survey, participants (n = 260) rated different treatment options for four case scenarios with AP in anterior/posterior teeth without/with previous RCT. Statistical analysis included the Friedman test for intra-case comparisons and Chi-squared test for factor-associations (p ≤ 0.05). Tooth retention using initial/repeated RCT was ranked first in all scenarios and rated as (very) appropriate by most participants, while implant-supported crowns (ISC) and apicoectomy had the second ratings. ISC were preferred more on posterior teeth or previous root-canal-treated teeth. Rating levels of treatment options displayed significant differences for all case scenarios. Posterior tooth retention by RCT demonstrated a significant association with work experience. Tooth retention with previous RCT displayed a significant correlation with dentists’ privately insured patients. Most dentists preferred tooth preserving with initial/repeated RCT, while others selected non-evidence-based choices. This reflects a lack of consensus of AP treatment decisions in Germany. Fixed treatment guidelines and further evaluation of treatment–decision-correlated factors are recommended for correct treatment planning.

In vitro Candida albicans biofilm formation on different titanium surface topographies

Objectives

To investigate if differences in titanium implant surface topography influence Candida albicans biofilm formation.

Materials and Methods

Titanium discs were prepared and characterized using a profilometer: Group A (R_a 0.15 µm, smooth), Group B (R_a 0.64 µm, minimally rough) and Group C (R_a 1.3 µm, moderately rough). Contact angle and surface free energy (SFE) were determined for each group. Non-preconditioned titanium discs were incubated with C. albicans for 24 h. In additional experiments, the titanium discs were initially coated with human saliva, bovine serum albumin or phosphate-buffered saline for 2 h before incubation with C. albicans for 24 h. The amount of fungal biofilm formation was quantified using a colorimetric assay.

Results

C. albicans biofilm formation was significantly lower (p < 0.05) on the minimally rough titanium surface compared to smooth and moderately rough surfaces. The titanium surface displaying the lowest SFE (Group B) was associated with significantly lower (p < 0.05) C. albicans biofilm formation than the other two groups. Salivary coating resulted in greater adherence of C. albicans with increased surface roughness.

Conclusions

The minimally rough titanium discs displayed lowest SFE compared to smooth and moderately rough surfaces and showed the least C. albicans biofilm formation. This study demonstrated that C. albicans biofilm formation increased in a SFE-dependent manner. These findings suggest that SFE might be a more explanatory factor for C. albicans biofilm formation on titanium surfaces than roughness. The presence of a pellicle coating may negate the impact of SFE on C. albicans biofilm formation on titanium surfaces.

Evaluation of osteogenic and antibacterial properties of strontium/silver-containing porous TiO2 coatings prepared by micro-arc oxidation

Ti and Ti alloys are bioinert materials and two frequent problems associated with them are bacterial infection and lack of osteogenic potential for rapid bone integration. To overcome the problems, the present study incorporated strontium (Sr) and silver (Ag) simultaneously into porous TiO₂ coatings through a single-step technique, micro-arc oxidation (MAO). Incorporation of Sr and Ag brought no significant changes to coating micromorphology and physicochemical properties, but endowed TiO₂ coatings with both strong antibacterial activity and osteogenic ability. Antibacterial activity increased with Ag contents in the coatings. When Ag content reached 0.58 wt%, the coating showed both excellent short-term (100.0%) and long-term (77.6%) antibacterial activities. Sr/Ag-containing coatings with 18.23 wt% Sr and 0.58 wt% Ag also presented good cytocompatibility for preosteoblast adhesion and proliferation, and promoted preosteoblast osteogenic differentiation both short-termly and long-termly. However, higher Ag content (1.29 wt%) showed toxic effects to preosteoblasts. In summary, MAO is a simple and effective way to incorporate Sr and Ag into porous TiO₂ coatings and Sr/Ag-containing TiO₂ coating with 18.5 wt% Sr and 0.58 wt% Ag has both good osteogenic activity and strong antibacterial capability short-termly and long-termly. Therefore, such coatings are valuable for clinical application to strengthen osseointegration and long-term high quality use of titanum implants.

Clinical guideline and treatment planning decisions of single-tooth implants versus preserving natural teeth with nonsurgical endodontic therapy

The outcomes of both dental implants and endodontically treated teeth have been extensively studied. An assessment of whether to rehabilitate a tooth requiring endodontic treatment or to replace it with a dental implant can often involve a challenging and complex decision making process for clinicians now a days. This review describes practical criteria and a systematic process to aid the treatment planning decision of whether to preserve teeth by root canal treatment (RCT) or extract and provide an implant. This article reviews the benefits and disadvantages of both treatment options and discusses success vs. survival outcomes.

Single Tooth Prosthetic Restoration Through Surgical Crown Lengthening, Conservative Therapies and CAD-CAM Milled Restoration in Lithium-Disilicate. A Case Report

Objective

The restorative treatment of a decayed, non-vital upper premolar often requires an interdisciplinary approach. Esthetics and the entity of the masticatory loads are usually affecting the choice of procedures and materials. A conservative treatment in a case with esthetic needs and functional requirements is investigated in this case report.

Materials and methods

A case of a 45- year- old woman with a severely decayed upper premolar is presented. The tooth has been previously treated in an emergency department with a provisional endodontic medication, but a further treatment has been then performed. The tooth was painful at the moment of the visit and the carious lesion appeared to invade the subgingival level. A surgical-conservative approach has been selected involving crown lengthening, endodontic treatment and a prosthetic crown with a monolithic Lithium-Silicate.

Results

The rehabilitative process required 3 months, including maturation times after surgery and the placement of the provisional crown. The patient claimed to be both esthetically and functionally satisfied with the restoration.

Conclusion

A conservative treatment of a severely involved tooth requires a critical evaluation of the remaining structures and a precise selection of the restorative materials. A monolithic crown could represent an ideal solution for restoring an upper premolar requiring esthetics and solid function, but the choice of a high translucent, easily polishable and possibly even chair-side prosthetic material might be an appreciable added value for clinicians.

Tissue Engineering Approaches for Enamel, Dentin, and Pulp Regeneration: An Update

Stem/progenitor cells are undifferentiated cells characterized by their exclusive ability for self-renewal and multilineage differentiation potential. In recent years, researchers and investigations explored the prospect of employing stem/progenitor cell therapy in regenerative medicine, especially stem/progenitor cells originating from the oral tissues. In this context, the regeneration of the lost dental tissues including enamel, dentin, and the dental pulp are pivotal targets for stem/progenitor cell therapy. The present review elaborates on the different sources of stem/progenitor cells and their potential clinical applications to regenerate enamel, dentin, and the dental pulpal tissues.

In the Dental Implant Era, Why Do We Still Bother Saving Teeth?

Teeth are vital sensory organs that contribute to our daily activities of living. Unfortunately, teeth can be lost for several reasons including trauma, caries, and periodontal disease. Although dental trauma injuries and caries are more frequently encountered in a younger population, tooth loss because of periodontal disease occurs in the older population. In the dental implant era, the trend sometimes seems to be to extract compromised teeth and replace them with dental implants. However, the long-term prognosis of teeth might not be comparable with the prognosis of dental implants. Complications, failures, and diseases such as peri-implantitis are not uncommon, and, despite popular belief, implants are not 99% successful. Other treatment options that aim to save compromised or diseased teeth such as endodontic treatment, periodontal treatment, intentional replantation, and autotransplantation should be considered on an individual basis. These treatments have competing success rates to dental implants but, more importantly, retain the natural tooth in the dentition for a longer period of time. These options are important to discuss in detail during treatment planning with patients in order to clarify any misconceptions about teeth and dental implants. In the event a tooth does have to be extracted, procedures such as decoronation and orthodontic extrusion might be useful to preserve hard and soft tissues for future dental implant placement. Regardless of the treatment modality, it is critical that strict maintenance and follow-up protocols are implemented and that treatment planning is ethically responsible and evidence based.

Stem/progenitor cell-mediated pulpal tissue regeneration: a systematic review and meta-analysis

BACKGROUND

Stem/progenitor cell-mediated pulpal regeneration could represent a promising therapeutic alternative in the field of clinical endodontics.

AIM

The present study aimed to systematically assess and meta-analyse dental pulpal tissue regeneration, pulpal vitality and apical healing after the transplantation of stem/progenitor cells versus no transplantation.

DATA SOURCES

MEDLINE, Cochrane CENTRAL and EMBASE were searched up to January 2019 for animal experiments and human trials evaluating the pulpal transplantation of stem/progenitor cells. Cross-referencing and hand search were additionally performed.

STUDY ELIGIBILITY CRITERIA, PARTICIPANTS AND INTERVENTIONS

Based on randomized controlled clinical trials (RCTs) or controlled clinical trials (CCTs), conducted in animals or humans, the effect of the transplantation of stem/progenitor cells compared to no transplantation on pulpal tissue regeneration, pulpal vitality and apical healing was examined.

STUDY APPRAISAL AND SYNTHESIS METHODS

The primary outcome was histologically determined pulpal tissue regeneration, whilst pulpal vitality and apical healing were secondary outcomes. The SYstematic Review Centre for Laboratory animal Experimentation (SYRCLE) guidelines and the revised Cochrane risk of bias tool (RoB 2.0) were used for risk-of-bias assessment. Pooled standardized differences in means (SDM) and 95% confidence intervals (95% CI) were calculated using random-effects meta-analyses.

RESULTS

From 2834 identified articles, eight animal experiments (82 animals with 336 experimental pulpal defects) and one human trial (40 humans with 40 pulpal defects) were included. Risk of bias of most animal studies was high, whilst the human trial revealed 'some concerns'. Stem/progenitor cell-transplanted pulps demonstrated significantly increased pulpal tissue regeneration compared with controls (SDM [95%CI]: 6.29 [3.78-8.80]).

LIMITATIONS

Data on pulpal vitality and apical healing were sparse and inconsistent. Heterogeneity across studies was substantial, publication bias was present, and mainly indirect, surrogate outcome measures were applied. The overall strength of evidence was very low.

CONCLUSIONS AND IMPLICATIONS OF KEY FINDINGS

The transplanation of stem/progenitor cells shows promise for pulp regeneration, whilst clinical routine application is still not in reach. Further investigations, employing a comprehensive set of outcomes including those demonstrating functional pulp regeneration relevant for patient-centred care, are required.

Dentists and Dental Intern’s Preferences of Root Canal Treatment with Restoration Versus Extraction then Implant-Supported Crown Treatment Plan

Objectives:

The intent of this study was to evaluate and compare the preferences and treatment choices between dentists and dental interns with regard to the following different treatment modalities: Root Canal Treatment (RCT) with restoration versus extraction with Implant-Supported Crown (ISC) or surgical treatment in relation to the given case scenarios.

Methods:

The questionnaire was presented as an online survey with a case scenario. The total number of the respondents were 165. The four clinical case scenarios included an anterior and posterior tooth having apical periodontitis, with and without previous RCT. The treatment options were as follows: RCT with restoration, extraction then implant, and surgical treatment.

Results:

A total of 165 dentists and dental interns were included in this study. A hundred and three 62.4% respondents were dentists, 60; 36.3% were males and 105; 63.7% were females. Most of the respondents graduated from the College of Dentistry, Jazan University (93.9%). The highest percentages and numbers for Anterior Teeth (AT) were selected in related to the RCT and restorations in the four scenarios among gender, dentists, and interns, with no considerable differences. A high percentage of RCT and restoration option was recorded for Posterior Teeth (PT) with no previous restoration and around 50% for the same treatment modality to posterior teeth with previous restorations. For Future Planning Postgraduate Studies (FPPS), it was obvious that most of the selected specialties agreed with the RCT and restorations choice.

Conclusion:

All dentists and interns in both genders preferred RCT with restorations over extraction, and then ISC in the AT with and without previous RCTs. In the PT with no previous RCT, the participants agreed that RCT with restorations is superior to other choices. Among the FPPS, the respondents demonstrated an absolute agreement to RCT and restorations as a treatment of choice for different scenarios.

Clinical Significance:

Dentists should preserve the natural teeth by RCT with restoration as the first treatment choice followed by other choices. The nonsurgical approach should always be adopted as a routine measure in PA lesions of endodontic origin. Conservative orthograde endodontic therapy demonstrates favorable outcomes with a regular periodic review and assessment of the healing process of PA lesions.

[Criteria for success in dental implants]

With the comprehensive application and development of implant dentistry in recent years, multi-institutional data have supported a large number of clinical research findings. A consensus was gradually reached on the evaluation of the state and effect of implants and types of indicators that were selected after restoration. This study aims to examine the frequently used criteria to define treatment success in implant dentistry.

Antibiofilm peptides against biofilms on titanium and hydroxyapatite surfaces

Biofilms are the main challenges in the treatment of common oral diseases such as caries, gingival and endodontic infection and periimplantitis. Oral plaque is the origin of microbes colonizing in the form of biofilms on hydroxyapatite (tooth) and titanium (dental implant) surfaces. In this study, hydroxyapatite (HA) and titanium (Ti) disks were introduced, and their surface morphology was both qualitatively and quantitatively analyzed by a scanning electron microscope (SEM) and atomic force microscope (AFM). The average roughness of Ti disks (77.6 ± 18.3 nm) was less than that of HA (146.1 ± 38.5 nm) (p < 0.05). Oral multispecies biofilms which were cultured on Ti and HA disks for 6 h and three weeks were visualized by SEM. We investigated the ability of two new antibiofilm peptides, DJK-5 and 1018, to induce killing of bacteria in oral multispecies biofilms on Ti and HA disks. A 6-h treatment by DJK-5 and 1018 (2 or 10 μg/mL) significantly reduced biomass of the multispecies biofilms on both Ti and HA disks. DJK-5 was able to kill more bacteria (40.4-75.9%) than 1018 (30.4-67.0%) on both surfaces (p < 0.05). DJK-5 also led to a more effective killing of microbes after a 3-min treatment of 3-day-old and 3-week-old biofilms on Ti and HA surfaces, compared to peptide 1018 and chlorhexidine (p < 0.05). No significant difference was found in the amount of biofilm killing between Ti and HA surfaces. Both peptide DJK-5 and 1018 may potentially be used as effective antibiofilm agents in clinical dentistry.

Dental stem cell and dental tissue regeneration

The teeth are highly differentiated chewing organs formed by the development of tooth germ tissue located in the jaw and consist of the enamel, dentin, cementum, pulp, and periodontal tissue. Moreover, the teeth have a complicated regulatory mechanism, special histologic origin, diverse structure, and important function in mastication, articulation, and aesthetics. These characteristics, to a certain extent, greatly complicate the research in tooth regeneration. Recently, new ideas for tooth and tissue regeneration have begun to appear with rapid developments in the theories and technologies in tissue engineering. Numerous types of stem cells have been isolated from dental tissue, such as dental pulp stem cells (DPSCs), stem cells isolated from human pulp of exfoliated deciduous teeth (SHED), periodontal ligament stem cells (PDLSCs), stem cells from apical papilla (SCAPs), and dental follicle cells (DFCs). All these cells can regenerate the tissue of tooth. This review outlines the cell types and strategies of stem cell therapy applied in tooth regeneration, in order to provide theoretical basis for clinical treatments.

Loss of natural abutment teeth with cast copings retaining overdentures: a systematic review and meta-analysis

PURPOSE

To analyze the available evidence in the English, German and Japanese literature on the survival and complications of natural teeth with cast copings used to retain overdentures (ROD).

STUDY SELECTION

A systematic search strategy was conducted using MeSH terms and pre-defined criteria. Two groups of researchers searched Pubmed, CENTRAL, Embase (English, German), Ichushi-web (Japanese) as well as hand searching. Data were extracted independently by the two groups. The estimated frequency of abutment tooth loss was calculated from data on the number of lost teeth and exposure time. A meta-analysis was conducted to estimate the annual frequency of abutment tooth loss across all included studies.

RESULTS

A total of 4791 eligible studies from PubMed, Embase, and CENTRAL. An additional 316 articles were identified from the Ichushi-Web plus another 131 articles from additional sources. From those manuscripts, 19 reported relevant outcome data that was then extracted. The pooled data included a total of 1954 abutment teeth with a combined total exposure time of 9098 years. The estimated linear rate of loss was 1.76 %/year (95 %CI 1.13; 2.72). Caries and periodontal infections were identified as the most common reasons for abutment tooth loss.

CONCLUSIONS

Natural tooth retained overdentures often constitute the last resort before edentulism and might aid in this transition, especially in very old patients with reduced adaptive capacities. Given correct design, preparation and aftercare, RODs with cast copings, still are a valid treatment option in partially edentulous patients.

An In Vitro Model for Candida albicans⁻Streptococcus gordonii Biofilms on Titanium Surfaces

The oral cavity serves as a nutrient-rich haven for over 600 species of microorganisms. Although many are essential to maintaining the oral microbiota, some can cause oral infections such as caries, periodontitis, mucositis, and endodontic infections, and this is further exacerbated with dental implants. Most of these infections are mixed species in nature and associated with a biofilm mode of growth. Here, after optimization of different parameters including cell density, growth media, and incubation conditions, we have developed an in vitro model of C. albicans–S. gordonii mixed-species biofilms on titanium discs that is relevant to infections of peri-implant diseases. Our results indicate a synergistic effect for the development of biofilms when both microorganisms were seeded together, confirming the existence of beneficial, mutualistic cross-kingdom interactions for biofilm formation. The morphological and architectural features of these dual-species biofilms formed on titanium were determined using scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). Mixed biofilms formed on titanium discs showed a high level of resistance to combination therapy with antifungal and antibacterial drugs. This model can serve as a platform for further analyses of complex fungal/bacterial biofilms and can also be applied to screening of new drug candidates against mixed-species biofilms.

Genome analysis and clinical implications of the bacterial communities in early biofilm formation on dental implants restored with titanium or zirconia abutments

This cross-sectional study aimed to identify and quantify up to 42 target species colonizing the early biofilm of dental implants restored with titanium or zirconia abutments. A total of 720 samples from 20 healthy individuals were investigated. Biofilm samples were collected from the peri-implant sulci, inner parts of implants, abutment surfaces and prosthetic crowns over a functioning period of 30 days. Checkerboard DNA-DNA hybridization was used for microbial detection and quantitation. Clinical characteristics (probing depth, bleeding on probing, clinical attachment level and marginal bone loss) were also investigated during the monitoring period. Genome counts were low at the implant loading time point for both the abutment materials, and increased over time. Both the titanium and the zirconia groups presented similar microbial counts and diversity over time, and the microbiota was very similar to that colonizing the remaining teeth. Clinical findings were consistent with a healthy condition with no significant difference regarding marginal bone loss between the two materials.

A retrospective evaluation of 128 socket-shield cases in the esthetic zone and posterior sites: Partial extraction therapy with up to 4 years follow-up

OBJECTIVES

Tooth loss results in an inevitable alveolar ridge reduction. This has established a cautionary approach to extract, wait, augment, and insert the implant, in lieu of immediate placement. However, saving the tooth or part of it whenever possible is more conservative and supports the vital periodontal tissue buccofacial to an implant. The purpose of this cases series was to report on implant survival using this technique in a large cohort of patients at mid-term follow-up.

MATERIALS AND METHODS

A private practice patient database was searched for all patients having received socket-shield treatment in conjunction with immediate implant placement. Of the results returned, 128 met the inclusion criteria of ≥12 months from date of restoration, or failing prior to definitive restoration. These patients were recalled for evaluation of the restored implants up to 4 years post-treatment.

RESULTS

Seventy immediate implants with socket-shields were placed in female patients and 58 in males, age range 24-71 (mean 39 years). The distribution of sites treated were: maxillary incisors (64%), premolars (22%), canines (14%); maxilla (89.9%), mandible (10.1%). 123/128 implants osseointegrated and survived 1-4 years following restoration (survival rate 96.1%). A combined complication rate of 25/128 implants occurred (19.5%). Five implants failed to osseointegrate and were removed. The remaining 20 complications were all managed or observed without management, with implants surviving at mid-term follow-up.

CONCLUSIONS

Notwithstanding technique sensitivity and the need for randomized control studies, this case series demonstrates that the socket-shield performs competitively when compared to implant survival rates in both conventional immediate and delayed implant placement.

Dentin-like versus Rigid Endodontic Post: 11-year Randomized Controlled Pilot Trial on No-wall to 2-wall Defects

INTRODUCTION

This is the first long-term randomized controlled trial to evaluate dentin-like glass fiber posts (GFPs) compared with rather rigid titanium posts (TPs) for post-endodontic restoration of severely damaged endodontically treated teeth with 2 or fewer remaining cavity walls.

METHODS

Ninety-one subjects in need of post-endodontic restorations were randomly assigned to receive either a tapered GFP (n = 45) or TP (n = 46). Posts were adhesively luted by using self-adhesive resin cement, followed by composite core build-up and preparation of 2-mm ferrule design. Primary end point was loss of restoration for any reason. Kaplan-Meier curves were constructed, and log-rank test was calculated (P < .05).

RESULTS

After a follow-up of 132 months, 17 GFP and 20 TP restorations survived, and 19 failed (12 GFP, 7 TP). Failure modes for GFP were root fracture (n = 4), core fracture (n = 1), secondary caries (n = 1), endodontic failure (n = 2), extraction because of tooth mobility grade III associated with insufficient design of removable partial denture (n = 1), tooth fracture (n = 1), and changes in treatment plan (n = 2); failure modes for TP were endodontic failure (n = 5), root fracture (n = 1), and 1 extraction for other reasons. Cumulative survival probability was 58.7% for GFP and 74.2% for TP.

CONCLUSIONS

When using self-adhesively luted prefabricated posts, resin composite core build-up, and 2-mm ferrule to reconstruct severely damaged endodontically treated teeth, tooth survival is not influenced by post rigidity. Survival decreased rapidly after 8 years of observation in both groups.

Use of photo-Fenton's reaction by 400-nm LED light for endodontic disinfection: A preliminary in vitro study on Enterococcus faecalis

One of the biggest challenges in endodontics is the complete disinfection of root canals. In addition to mechanical preparation, the technique traditionally also involves channel disinfection with other agents such as sodium hypochlorite, hydrogen peroxide, chlorhexidine, or a combination of these. Some bacterial species are particularly resistant to eradication. Using Enterococcus faecalis in this preliminary study, we tested the bactericidal effectiveness of the Fenton reaction and the photo-Fenton reaction using an LED light with a 400-nm wavelength. Discs of hydroxyapatite were incubated in brain-heart broth contaminated with Enterococcus faecalis. After 4days, they were decontaminated with different bactericidal agents, including some with proven and well-known efficacy (5% sodium hypochlorite and 3% hydrogen peroxide) and other treatments using solutions of 1.5% hydrogen peroxide and 0.15% iron gluconate (Fenton reaction) plus LED light at a Fluence of 4.0J/cm² (photo-Fenton reaction). The photo-Fenton reaction demonstrated comparable performance to that of sodium hypochlorite in eliminating Enterococcus faecalis.