Proposal regarding potential causes related to certain complications with dental implants and adjacent natural teeth: Physics applied to prosthodontics.

PURPOSE: Complications can and do occur with implants and their restorations with causes having been proposed for some single implant complications but not for others. METHODS: A review of pertinent literature was conducted. A PubMed search of vibration, movement, and dentistry had 175 citations, while stress waves, movement, and dentistry had zero citations as did stress waves, movement. This paper discusses the physics of vibration, elastic and inelastic collision, and stress waves as potentially causative factors related to clinical complications. RESULTS: Multiple potential causes for interproximal contact loss have been presented, but it has not been fully understood. Likewise, theories have been suggested regarding the intrusion of natural teeth when they are connected to an implant as part of a fixed partial denture as well as intrusion when a tooth is located between adjacent implants, but the process of intrusion, and resultant extrusion, is not fully understood. A third complication with single implants and their crowns is abutment screw loosening with several of the clinical characteristics having been discussed but without determining the underlying process(es). CONCLUSIONS: Interproximal contact loss, natural tooth intrusion, and abutment screw loosening are common complications that occur with implant retained restorations. Occlusion is a significant confounding variable. The hypothesis is that vibration, or possibly stress waves, generated from occlusal impact forces on implant crowns and transmitted to adjacent teeth, are the causative factors in these events. Since occlusion appears to play a role in these complications, it is recommended that occlusal contacts provide centralized stability on implant crowns and not be located on any inclined surfaces that transmit lateral forces that could be transmitted to an adjacent tooth and cause interproximal contact loss or intrusion. The intensity, form, and location of proximal contacts between a natural tooth located between adjacent single implant crowns seem to play a role in the intrusion of the natural tooth. Currently, there is a lack of information about the underlying mechanisms related to these occurrences and research is needed to define any confounding variables.

A decision-making tree for evaluating an esthetically compromised single dental implant.

OBJECTIVE: To develop a comprehensive decision-making tree for evaluating mid-facial peri-implant soft tissue dehiscence in the esthetic zone and provide a systematic approach for assessing various clinical case scenarios, determining appropriate treatment strategies, and considering factors such as the need for soft tissue augmentation, prosthetic changes, or implant removal. CLINICAL CONSIDERATIONS: This clinical decision tree illustrates numerous case scenarios with various esthetic complications around an esthetically compromised, but clinically healthy single implant and provides clinicians with possible solutions as a predictable map for horizontal and vertical soft tissue augmentation in order to manage different clinical circumstances. According to current evidence, the key to treating such esthetic complications is the use of an adequate pre-surgical prosthetic interdisciplinary approach with proper surgical techniques in order to optimize soft tissue dimensions and create better esthetic results. This may be accomplished through a purely surgical, combination of surgical and prosthetic, or purely prosthetic approaches. CONCLUSIONS: The present report describes a series of successfully treated peri-implant esthetic complication cases in accordance with the decision-making tree that the authors recommend in order to achieve better long-term esthetic outcomes. CLINICAL SIGNIFICANCE: The combination of adequate pre-surgical prosthetic interdisciplinary collaboration and proper surgical technique is critical in the optimization of sufficient soft tissue dimensions and contributes to a more highly esthetic result. This study demonstrates a clinical decision-making tree to provide comprehensive, effective therapy of an esthetically compromised dental implant by using one of the following approaches: purely prosthetic, purely surgical, or a combination of surgical and prosthetic with or without abutment removal.

A comparative analysis of dual-axis implants placed into maxillary anterior extraction sockets versus virtual planning with uniaxial implants: A simulated cone beam computed tomography study of implant length and diameter.

OBJECTIVE: The biaxial nature of the anterior maxilla poses a surgical and restorative challenge in implant dentistry. The present study sought to investigate the apical socket perforation rate (ASPR) from a simulated uniaxial implant placement and to determine the effect of implant length and diameter on ASPR when a uniaxial implant was placed compared with the orientation of the pre-existing dual-axis implant. MATERIAL AND METHOD: Cone beam computed tomography (CBCT) scans from the database of three private practices were searched for patients who received dual-axis implants within the esthetic zone in immediate tooth replacement therapy. A uniaxial implant was virtually placed using the pre-existing screw access channel of the dual-axis implant as a reference. The closest length and diameter were selected for the simulated implant. ASPR by the uniaxial implant was recorded. In addition, the affordable maximum length of a corresponding uniaxial implant that would avoid apical socket perforation was measured. RESULT: Eighty-one patients with a total of 101 dual-axis dental implants were selected for analysis. A simulated virtual surgical planning with uniaxial implants revealed high ASPR (48.51%). When the length of the uniaxial implant was reduced to 11 and 9 mm, ASPR was decreased to 41.58% and 20.79%, respectively. CONCLUSION: Dual-axis implant design effectively evades anatomical challenges in the anterior maxilla (esthetic zone). Considering the current evidence, efforts should be made to carefully consider the angular disparity between the extraction socket-alveolus complex and the future restorative emergence so that a harmonious biologic-esthetic result may be more predictably and consistently obtained.

Selective Serotonin Reuptake Inhibitors and Dental Implant Failure: A Systematic Review and Meta-Analysis.

Selective serotonin reuptake inhibitors (SSRI) are commonly prescribed to treat mental health disorders, and previously published literature, although scarce, has shown a significant association between SSRI use and dental implant failure. This systematic review and meta-analysis aimed to examine whether such an association exists and, if so, to determine its strength. Reviewers performed an extensive search of the literature, last accessed in June 2022 in PubMed/Medline, Embase, and Cochrane databases using MeSH terms. Retrospective and prospective observational cohort and experimental studies evaluating the role of SSRI on dental implant failure among individuals ≥18 years of age, with a minimum follow-up of 6 months after implant placement, were deemed eligible. The search yielded a total of 6 eligible studies, all retrospective cohorts. Statistical analyses were performed using the statistical software R 4.1.3. Results showed higher implant failure rates among SSRI users vs non-SSRI users at both the patient level (5.6%-19.6% vs 1.9%-8.0%) and the implant level (5.6%-12.5% vs 1.9%-5.8%). The pooled relative risk (RR) of implant failure was more than double among SSRI users at the patient level (pooled RR: 2.44, 95% confidence interval [CI]: 1.68-3.55, P < .01) and at the implant level (pooled RR: 2.34, 95% CI: 1.74-3.15, P < .01) compared with non-SSRI users. DerSimonian and Laird estimates showed homogeneity of the studies (I2 = 0%, P > .05), and funnel plots and Egger's test determined no publication bias across all selected studies at both patient and implant levels. In conclusion, SSRI use is significantly associated with higher implant failure. Providers should be aware of this association and educate patients on the risk of implant therapy when obtaining informed consent.

The effect of implant macrogeometry in immediate tooth replacement therapy: A case series.

The concept of immediate tooth replacement therapy (ITRT) in the esthetic zone has become a viable treatment modality and widely accepted in clinical practice. However, achieving adequate primary stability that enables immediate provisional restoration and desirable space for bone-grafting with conventional tapered body implant designs is challenging. The macro-hybrid implant design with a prosthetic angle correction and body-shift feature in a singular form provides not only greater primary stability of a wider diameter implant but also circumferential gap distance both facially and interproximally preserve the labial bone plate and interdental attachment apparatus of the adjacent natural teeth thereby maintaining the interdental papilla. The present clinical series exemplifies the clinical advantages of this inverted body-shift implant design in ITRT in various clinical scenarios in (1) single tooth replacement in a Type 1 intact socket with a thin periodontal phenotype, (2) single tooth replacement in a Type 2 socket with a dentoalveolar dehiscence of the labial bone plate, and (3) multiple adjacent teeth replacement of two maxillary central incisor. CLINICAL SIGNIFICANCE: The macro-hybrid design implant with a prosthetic angle correction and body-shift feature in a singular form provides greater midfacial gap distance as well as tooth-to-implant distance to preserve the interdental attachment of the adjacent natural teeth thereby leaving the interdental papilla undisturbed, without sacrificing higher primary stability afforded by larger diameter implants.

Interdisciplinary management of recession defects on maxillary single tooth implants: Diagnosis and treatment strategies.

OBJECTIVE: One of the most common complications with dental implants placed in the smile zone is the development of mid-facial recession, creating an undesirable esthetic result. When deciding how to remediate these clinical scenarios, the question becomes whether it may be feasible to save the problematic implant or if it is more predictable to remove the implant and start all over again. However, patients may be invested emotionally, physically, and financially in the implant and remediation may be a viable option depending on the diagnosis of the specific issues at hand and multi-disciplinary clinical execution. CLINICAL SIGNIFICANCE: What is crucial to understand in order to remediate these cases is answering four separate criteria: (1) is the implant in a restorable position, (2) is the implant healthy, (3) is the implant placed at an adequate depth, and (4) are components available to restore the implant. CONCLUSIONS: Two different clinical reports are presented that demonstrate various treatment remedies when saving implants in the esthetic zone.

When to save or remove implants in the smile zone: A clinical report of maxillary lateral incisor implants in malposition.

OBJECTIVE: The following is a clinical report addressing when to save or remove implants with esthetic deficiencies in the smile zone as well as the sequence and timing of interdisciplinary treatment. CLINICAL CONSIDERATIONS: Key factors in the decision-making process in treating implants in malposition are whether the implants are (1) in a reasonable restorative position, (2) free of disease, and (3) placed with adequate depth. This clinical report encompassed periodontal corrective surgery, non-surgical soft tissue sculpting through subgingival crown contour, material selection for definitive restorations, and cementation techniques for cement-retained restorations. CLINICAL SIGNIFICANCE: Knowledge and understanding of interdisciplinary treatment planning, sequencing, and respective techniques that can be implemented when confronting implants in malposition in the smile zone will allow the interdisciplinary team to achieve the desired esthetic restorative result.

Parenchymal and stromal tissue regeneration of tooth organ by pivotal signals reinstated in decellularized matrix.

Cells are transplanted to regenerate an organs' parenchyma, but how transplanted parenchymal cells induce stromal regeneration is elusive. Despite the common use of a decellularized matrix, little is known as to the pivotal signals that must be restored for tissue or organ regeneration. We report that Alx3, a developmentally important gene, orchestrated adult parenchymal and stromal regeneration by directly transactivating Wnt3a and vascular endothelial growth factor. In contrast to the modest parenchyma formed by native adult progenitors, Alx3-restored cells in decellularized scaffolds not only produced vascularized stroma that involved vascular endothelial growth factor signalling, but also parenchymal dentin via the Wnt/ß-catenin pathway. In an orthotopic large-animal model following parenchyma and stroma ablation, Wnt3a-recruited endogenous cells regenerated neurovascular stroma and differentiated into parenchymal odontoblast-like cells that extended the processes into newly formed dentin with a structure-mechanical equivalency to native dentin. Thus, the Alx3-Wnt3a axis enables postnatal progenitors with a modest innate regenerative capacity to regenerate adult tissues. Depleted signals in the decellularized matrix may be reinstated by a developmentally pivotal gene or corresponding protein.

Layperson's Esthetic Preference to the Presence or Absence of the Interdental Papillae in the Low Smile Line: A Web-based Study.

PURPOSE: To determine the layperson's esthetic preference to the visual display (presence) or lack thereof (absence) of the interdental papillae during minimum smiling or the low smile line patient type. MATERIALS AND METHODS: Two hundred lay-people were shown three-paired smile images indicative of a low gingival smile line patient type in which the vermillion border of the maxillary lip covered the mid-facial gingiva of the anterior teeth. The three images differed only with respect to [1] presence of interdental papillae, [2] absence of the interdental papilla ("black triangle"), or [3] absence of the interdental papillae (replaced with a long restorative contact area). The three images were paired in multiple groupings; group-1 consisted of a comparison of the presence of interdental papillae vs the lack of the interdental papillae "black triangle," group-2 compared the long restorative contact compared to the presence of the interdental papillae and Group-3 compared the long restorative contact replacing a missing papilla to the absence of the interdental papillae "black triangle." The comparisons were designed to determine the subjective preference of lay individuals between these groupings. RESULTS: Ninety-eight percent of lay-people demonstrated a preference to the presence of the interdental papillae in the smile (image 1) when compared to its absence ("black triangle"; image 2) with a low smile line. Seventy percent preferred the visual display of the interdental papillae, that is, pink tissues (image 1), compared to the absence of the interdental papillae replaced with a long contact area (image 3), that is, white restorative materials, when viewing a low gingival smile line. And when comparing the absence of the interdental papillae "black triangle" to a long contact area, 92% of lay-people preferred a long contact area vs the absence of the interdental papillae with a "black triangle" with a low smile line. CONCLUSIONS: The visual display [presence] of the interdental papillae, that is, pink tissues, is notably preferred to the absence of the interdental papillae when replaced by either a "black triangle" or long contact area in the commonly known low smile line. This emphasizes the need to assess the Interdental Smile Line (ie, visual display of interdental papillae during smiling) in all patients and the importance to preserve and/or re-establishment of the interdental papillae, that is, pink tissues, even in patients with a low smile line.

Interproximal Open Contacts Between Implant Restorations and Adjacent Teeth. Prevalence - Causes - Possible Solutions.

PURPOSE: To present the prevalence and contributing factors of interproximal contact loss (ICL) between implant restorations and adjacent teeth, and to provide recommendations for possible prevention and treatment of this complication. MATERIALS AND METHODS: The authors explored the dental literature on PubMed on ICL between implants and adjacent teeth, interproximal contacts, open contacts, teeth migration causes, facial bone formation, and facial bone changes. RESULTS: ICL between fixed implant prostheses and adjacent teeth has been reported. A literature search revealed 7 studies showing a high prevalence of ICL between implant prostheses and adjacent teeth. The literature indicates that this ICL is greater in the mesial aspect in comparison with the distal. As identified by the literature review, ICL in the maxilla ranged between 18% and 66% versus 37% to 54% in the mandible. ICL might occur as early as 3 months after prosthetic treatment. The literature review documented possible tooth migration causes, crown-related causes, and bone formation/growth-related causes of ICL. CONCLUSIONS: ICL is a common multifactorial implant complication. The clinical condition will dictate if the implant crown needs to be modified/replaced or the natural tooth needs to be restored to reestablish interproximal contact between an implant prosthesis and adjacent tooth. Periodic evaluations of interproximal contacts between implant restorations and the adjacent teeth and the use of screw-retained restorations due to ease of removal is recommended to diagnose and mitigate the problem. An orthodontic retainer or occlusal guard may help prevent ICL between the implant restoration and the adjacent tooth.

A new technique to identify the location of the mucogingival junction on computer tomographic scans before implant placement.

A new technique is presented to identify the location of mucogingival junction (MGJ) on CT scans before implant placement. This case report describes the step-by-step fabrication of a radiographic template, which when used in conjunction with CT scans enables the clinician to locate the position of MGJ before implant placement and predict the amount of keratinized tissue (KT) that will be present around an implant. Using this technique, the operator can determine whether or not flapless implant surgery may be a treatment option and whether simultaneous soft tissue augmentation will be necessary at the time of implant placement to establish an adequate band of KT.

Immediate loading with fixed implant-supported restorations in an edentulous patient with an HIV infection: a case report.

BACKGROUND: Oral rehabilitation of edentulous patients with implants that are immediately loaded is a viable treatment alternative today; however, the immediate loading protocol has not been extensively documented in HIV-seropositive patients. METHODS: This clinical case report presents a surgical and prosthetic implant-supported immediate loading protocol in an edentulous HIV-seropositive patient (CD4 >200 and T4/T8: 0.99). Eight implants were placed in each jaw, and no ridge augmentation procedures were required. All the implants were connected with abutments, and a temporary fixed restoration was placed immediately after surgery. The final fixed reconstruction was cemented after 10 weeks of loading. RESULTS: All implants showed no clinical signs of mobility or infection. Periotest values were evaluated during healing and showed a progressive reduction. Radiological findings showed stable bone levels after an observation period of 4 years. CONCLUSIONS: This case report presents an alternative treatment for the oral rehabilitation of an HIV-positive (but disease asymptomatic) edentulous patient. The concept of immediate loading of implants offers advantages when compared with a traditional treatment modality even in immunocompromised patients who are well controlled.

A Paradigm Shift Using Scan Bodies to Record the Position of a Complete Arch of Implants in a Digital Workflow.

The use of conventional scan bodies (SBs) with an intraoral scanner (IOS) to capture the position of a complete arch of dental implants has proven to be challenging. The literature is unclear about the accuracy of intraoral scanning techniques using SBs that are connected vertically to multiunit abutments (MUAs) for numerous adjacent implants in the same arch. Recently, there has been a paradigm shift from vertical SBs to horizontal SBs, which are positioned perpendicular to the long axis of the MUAs. Most IOSs available today can capture these horizontal SBs, called scan gauges (SGs), with better accuracy and consequently acquire the position of multiple adjacent implants using an effective scan path, thus reducing stitching and the number of images. The key to implementing this novel technology is to strategically arrange the SGs to optimize horizontal overlap of multiple adjacent SGs without touching each other. By superimposing two high-resolution intraoral scans of the SGs, an artificial intelligence (AI) algorithm is employed to produce a calibrated digital best-fit model on which a passive complete-arch prosthesis can be designed and fabricated. The advantages and disadvantages of SBs and SGs are discussed, and a case report using a digital workflow is presented.

Successful Regenerative Therapy of Periodontal Defects Associated With Tongue Piercing: A Clinical Report.

Oral piercing habits are associated with various degrees of complications. Tongue piercing increases the risk of gingival recession and infrabony defects, subsequently leading to localized periodontitis. In the case presented, the patient had persistent swelling and suppuration around her mandibular anterior teeth attributed to tongue piercing jewelry that was placed approximately 12 years prior. Intraoral examinations revealed a localized deep pocket, purulent discharge, swelling, plaque accumulation, bleeding on probing, gingival recession, and teeth mobility. The patient was diagnosed with localized stage III, grade C periodontitis. Following full-mouth debridement and the placement of an extracoronal lingual splint, minimally invasive, papillae-sparing incisions were made, and regenerative therapy with bone allograft and collagen membrane was used to manage the infrabony defects. During the 18-month postoperative follow-up, complete soft-tissue healing was observed along with a significant reduction in pocket depth and the absence of bleeding on probing or suppuration. Radiographic evaluation showed evidence of bone fill. The reported case demonstrates how careful diagnosis and treatment planning are crucial for managing different periodontal defects and emphasizes the importance of proficient periodontal management, which can save teeth that would otherwise be extracted and replaced with implant therapy or fixed bridgework.

The effect of abutment dis/reconnections on peri-implant bone resorption: a radiologic study of platform-switched and non-platform-switched implants placed in animals.

OBJECTIVES: The purpose of this animal study was to radiologically measure the influence of abutment disconnection on bone resorption and to compare this influence on platform-switched vs. non-platform-switched implants. METHODS: The study design included extraction of all mandibular premolars in five canines . After 2 months, six implants were placed in each dog. Four of them were platform-switched (PS) implants and two were non-platform-switched (NPS) implants. Some or all of the abutments connected to the implants were disconnected at pre-ordained post-surgical intervals. Radiographs were taken at the time of implant placement and at every handling. The values for mesial (horizontal and vertical) and distal (horizontal and vertical) bone resorption were taken and compared for each implant at every abutment dis/reconnection. RESULTS: The average vertical bone resorption around NPS implants after four dis/reconnections was 1.09 mm (SD 0.25 mm), and the average horizontal bone resorption was 0.98 mm (SD 0.27 mm). The average vertical bone resorption around PS implants after four dis/reconnections was 0.24 mm, (SD 0.08 mm) and the average horizontal bone resorption was 0.24 mm (SD 0.13 mm). The difference of the average horizontal and vertical bone resorption around NPS (site D) and PS (site A) implants was statically significant (P < 0.05). The average mesial and distal bone resorption values around PS (site A) implant adjacent to a tooth were compared, and statically significant differences were found (P < 0.05). CONCLUSIONS: Implants with a PS design show less peri-implant bone resorption during the healing process and as their abutments are disconnected, than do comparably dis/reconnected NPS implants. The location of the PS implant next to a tooth may decrease radiographically visible peri-implant bone resorption significantly.

Subcrestal Implantoplasty for Treating Peri-implantitis With Regenerative Care-How Deep Should Treatment Go?

Used to treat implants failing due to peri-implantitis, implantoplasty has traditionally been performed in conjunction with a resective approach or to smooth the portion of the dental implant above the bone to facilitate oral hygiene efforts. This article demonstrates the use of implantoplasty to decontaminate the implant surface both above and below the crest of bone in an attempt to reosseointegrate the failing implant; to the authors' knowledge this is the first time in the literature that implantoplasty was used in this manner and demonstrated potential regenerative efficacy.

Association between oral bisphosphonate use and dental implant failure among middle-aged women.

AIM: To investigate the association between the use of oral bisphosphonate therapy and dental implant failure. MATERIALS AND METHODS: The case-control study involved 337 female patients, aged 40 years and older, who had 1181 implants placed at the Department of Periodontology and Implant Dentistry at New York University College of Dentistry between January 1997 and December 2004. Cases, defined as women with one or more implant failures, were identified from the departmental database. Controls were then randomly selected for each case. Adjusted odds ratios were estimated using logistic regression models fitted through generalized estimating equations. RESULTS: After adjusting for selected covariates, the odds of oral bisphosphonate use was 2.69 (95% confidence interval [CI], 1.49-4.86) times higher in women for whom implants failed compared with those for whom implants did not fail. Although no significant interaction was observed (p = 0.41), the stratified analyses suggest that the association between oral bisphosphonate use and dental implant failure was stronger in the maxilla (Odds Ratio [OR] = 2.60; 95% CI, 1.36-4.96) than in the mandible (OR = 1.38; 95% CI, 0.51-3.73). CONCLUSION: Findings from this study suggest that dental practitioners should be aware of the increased risk of implant failure associated with oral bisphosphonate use in the population.

The dual-zone therapeutic concept of managing immediate implant placement and provisional restoration in anterior extraction sockets.

Improvements in implant designs have helped advance successful immediate anterior implant placement into fresh extraction sockets. Clinical techniques described in this case enable practitioners to achieve predictable esthetic success using a method that limits the amount of buccal contour change of the extraction site ridge and potentially enhances the thickness of the peri-implant soft tissues coronal to the implant-abutment interface. This approach involves atraumatic tooth removal without flap elevation, and placing a bone graft into the residual gap around an immediate fresh-socket anterior implant with a screw-retained provisional restoration acting as a prosthetic socket seal device.

Maxillary sinus elevation by lateral window approach: evolution of technology and technique.

CONTEXT: The maxillary sinus elevation procedure has become an important pre-prosthetic surgical procedure for the creation of bone volume in the edentulous posterior maxilla for the placement of dental implants. Research and clinical experience over the past 30 years has increased the predictability of this procedure as well as reduced patient morbidity. EVIDENCE ACQUISITION: Data on grafting materials and implant survival rates comes from 10 published evidence-based reviews that include all relevant published data from 1980 to 2012. Supporting clinical material comes from the experience of the authors. EVIDENCE SYNTHESIS: The evidence-based reviews report and compare the implant survival rates utilizing various grafting materials, implant surfaces, and the use or non-use of barrier membranes over the lateral window. Clinical studies report on complication rates utilizing piezoelectric surgery and compare them to complication rates with rotary instrumentation. CONCLUSIONS: The conclusions of all the evidence-based reviews indicate that the utilization of bone replacement grafts, rough-surfaced implants, and barrier membranes result in the most positive outcomes when considering implant survival. Further, the utilization of piezoelectric surgery, rather than rotary diamond burs, for lateral window preparation and membrane separation leads to a dramatic reduction in the occurrence of the intraoperative complications of bleeding and membrane perforation.