Soft tissue topography and dimensions lateral to single implant-supported restorations. A cross-sectional study

Impact of Implant Mesiodistal Distance on Peri-Implant Bone Loss: A Cross-Sectional Retrospective Study

PURPOSE

The purpose of this study was to verify the effect of our previously proposed mesiodistal distance for multiple posterior implants on preserving peri-implant bone, and to provide a measurable criterion for predicting implant prognosis.

METHODS

One hundred and two patients with dental implants placed in the posterior free-end edentulous arches were recruited in this cross-sectional study. Calibrated X-rays (peri-apical [PA] or bite-wing x-ray) were collected to measure the mesiodistal space as well as the corresponding bone resorption of implants after prosthesis placement. Implants were assigned to the test/control group according to whether their mesiodistal distance following our proposed algorithm. After adjusting covariates, logistic multivariate regression analyses were performed to examine the relationship between inter-implant distance and marginal bone loss (MBL) during each follow-up interval. The effect of smoking habits was also analyzed.

RESULTS

Every observation period exhibited great significance between experimental and control group on peri-implant bone level (p = 0.006, 0.005, 0.001, 0.025, 0.001, correspondingly) and the difference had a tendency to grow as time went by except 4-year (MD = -0.19, -0.39, -0.43, -0.30, -1.26, correspondingly). While no significant difference was observed between smokers and nonsmokers in the same group (p > 0.05).

CONCLUSION

The mesiodistal algorithm of 4-4.6 mm (implant to adjacent canine tooth), 7-7.4 mm, 8-8.5 mm, and 9-9.5 mm was proved to be effective for maintaining peri-implant bone level. It was also observed in our study that the impact of inter-implant distance outweighed that of smoking. This study provided clinicians predictable prognostic outcomes for implants and reference for deciding treatment plans.

An Enigmatic Soft-Tissue Creeping Phenomenon: The Spontaneous Peri-Implant Mucosa Margin and Papilla Growth, Part Two-A Scientifically Supported Hypothesis Article

In our previous article, we observed and measured a spontaneous growth in the coronal direction of the keratinized tissues present around implants. This growth involved both free margins and interdental papillae, and we indicated our hypothesis on the probable cause of this still-unexplained phenomenon. The growth of oral soft tissues involves several other structures, such as the linea alba and tongue indentation. Our idea holds that growth of these tissues is generated by the negative intraoral pressure created in the oral phase of swallowing and the subsequent resting position, which through the resulting suction causes a shift of these soft structures in the gaps around the dental crowns. Other hypotheses have been suggested in the past to understand this phenomenon of soft tissue growth, which still lacks data supporting etiological evidence. The purpose of this article is to thoroughly analyze and verify our model by comparing the clinical observations with citations and examples from the literature, combined with notions of physiology, biology, and physics that help in clarifying these events. To better explain the mechanisms of oral soft tissue growth, photographs of clinical cases paradigmatic of the phenomenon are shown.

Longitudinal study on the effect of keratinized mucosal augmentation surrounding dental implants in preventing peri-implant bone loss

Background

Dental implant therapy is a well-established method of prosthetic rehabilitation of missing teeth. To maintain the health of the surrounding tissue, management of risk factors/indicators and daily maintenance are important. It still remains controversial whether a certain amount of keratinized mucosal width is essential for maintaining the health of peri-implant tissue. The purpose of this multicenter retrospective study was to assess the correlation between bone loss around dental implant and the amount of keratinized tissue width.

Methods

A total of 1,644 implants were evaluated. Data was collected about participants' general and dental history, as well as implant details. Bone resorption around implant was calculated from intra-oral radiographs taken after 1 year and more than 3 years of function. Implants were classified into three groups; received free gingival graft or apically repositioned flap surgery for increasing the keratinized mucosa ≥2 mm width (group A), keratinized mucosa width ≥2 mm (group B), and keratinized mucosa width <2 mm (group C). These data were analyzed by propensity score analysis and a generalized linear regression analysis was performed to compare the bone resorption among groups.

Results

Mean functional time was 55.8 months (SD = 20.5) in group A, 67.6 months (SD = 28.1) in group B, and 74.5 months (SD = 32.9) in group C. Mean bone resorption of groups A, B, and C were 0.08 mm (SD = 0.40), 0.18 mm (SD = 0.66), and 0.44 mm (SD = 0.40). Groups A and B had significantly lower bone resorption than group C.

Conclusion

The results in this study show the importance of keratinized mucosa in maintaining the peri-implant bone. Our findings also suggest that mucosal transplantation is useful, as opposed to narrowing of the keratinized mucosa.

Average and Maximum Papilla Heights around Dental Implants in the Anterior Maxillary Region: A Retrospective Clinical Study

Objective

The aim of this study was to determine the average and maximum height of the papilla around maxillary anterior implants in respect of neighboring structures and location of implants.

Materials and Methods

92 dental implants from 63 patients were investigated in this study. Those implants were placed in the anterior maxillary region and had been loaded for a minimum of one year. After receiving written consent, clinical data including the height of interproximal papillae adjacent to the tooth/implant/pontic were obtained through clinical observation. The independent t-test or ANOVA, the regression modeling, and generalized estimating equation (GEE) models were used for statistical analysis (p < 0.05).

Results

Papilla height was calculated as 2.8 mm (1–5.5 mm) for implant-tooth sites, 2.6 mm (1–4 mm) in implants beside pontics, and 2.5 mm (1–3.5 mm) for implants adjacent to implants. Despite the lack of a significant difference in the mean papilla height in the studied groups, the maximum values of papilla heights were significantly different.

Conclusions

In this study, no significant differences were found in papilla height mean values in relation to neighboring structures or location of implants in the anterior maxilla. However, the maximum values of papilla heights were observed around implants next to natural teeth.

Esthetic complications in implant dentistry

Esthetic complications in implant dentistry have become a significant consideration for patients and practitioners. This review presents an appraisal on the current knowledge of the physiological peri-implant soft-tissue dimensions and factors that may compromise peri-implant tissue esthetics. Factors such as papilla fill adjacent to the implant and midfacial mucosal height are critical parameters that determine the esthetic success of implant-supported restorations. Papilla fill adjacent to a single dental implant appears to depend upon the clinical attachment level of the neighboring tooth. A horizontal inter-implant distance of at least 3 mm is necessary to ensure optimal interproximal mucosal embrasure between two adjacent implants in the anterior maxilla. In cases where implants cannot be placed at least 3 mm apart, a single implant with a cantilever bridge should be considered. Buccolingual implant positioning plays a major role in midfacial mucosal height. Soft-tissue volume grafting following immediate implant placement in the presence of a thin soft-tissue phenotype or simultaneous to surgical peri-implantitis therapy might help to overcome facial mucosa recession.

The peri-implant phenotype and implant esthetic complications. Contemporary overview

OBJECTIVE

To provide a contemporary and comprehensive overview of the hard and soft tissue biological structures surrounding an osseointegrated dental implant (peri-implant referred to as the peri-implant phenotype), in the context of peri-implant esthetic complications.

OVERVIEW

The individual components of the peri-implant phenotype (keratinized mucosa width, mucosal thickness, supracrestal tissue height, and the peri-implant buccal bone) have been linked to different aspects of implant esthetics, as well as health-related aspects. At the time of implant therapy, respecting the biology of the peri-implant hard and soft tissues, and anticipating their remodeling patterns can alleviate future esthetic complications.

CONCLUSIONS

While the current literature may not allow for a point-by-point evidence based-recommendation for the required amount of each peri-implant structure, bearing in mind the proposed values for the components of the peri-implant phenotype, at the time of and prior to implant therapy can lead to more predictable treatment outcomes, and the avoidance of esthetic complications.

CLINICAL SIGNIFICANCE

Knowledge of hard and soft tissue components surrounding and osseointegrated dental implant, and their underlying biological remodeling process is crucial for carrying out a successful therapy and alleviating possible future esthetic challenges.

An enigmatic soft tissue creeping phenomenon: The spontaneous peri-implant mucosa margin and papilla growth. A retrospective clinical study

Objectives

The aim of the present retrospective study was to evaluate papillae filling rate and buccal margins coronal growth in implant‐supported prostheses which were over‐contoured at the apical buccal third to form a rearmost collar zone, thus mimicking a false root.

Material and methods

The influence of adjacent elements, teeth, implants, or pontics was examined. One‐hundred and three crowns have been assessed in photographs taken on 61 patients after prosthesis delivering and at last follow‐up (mean 2.8 years). The Jemt index was adopted to evaluate papillae growth at the baseline and follow‐up as follows: 0, absence of papilla; 1, less than half of interdental embrasure height; 2, more than half of interdental embrasure height; 3, fully papilla filled interdental embrasure. Index score 4, papilla hyperplasia was not included. Moreover, the coronal growth (or recession) of buccal mucosa in implant‐supported crowns was assessed.

Results

At baseline, a total of 29 papillae had a 0 score, while only two scored 3 with complete papilla formation. On follow‐up, only one papilla scored 0, while 46 scored 3 with complete interdental embrasures filling. The highest papilla score was registered from first year crown insertion and likewise in interdental embrasures located between two implants or implants and pontics. Moreover, the buccal margin growth was observed in almost 80% of crowns. Such findings seem to indicate that buccal margin and papilla around implant‐supported crowns presented a coronal growth over time, especially during its first year. The average papilla growth between two implants was no lower than that observed in papilla present between implants and natural teeth.

Conclusions

Recessed areas at collar of implant‐supported prostheses appear to positively influence papillae and buccal margin growth, especially in its first year. Papilla growth between two implants was similar to that observed between implants and natural teeth.

Aesthetic aspects of adjacent maxillary single-crown implants-influence of zirconia and titanium as implant materials

The purpose of this retrospective survey was to assess the esthetic aspects of adjacent zirconia and titanium implants in the anterior maxillary area. A total of 40 patients and 109 adjacent implants (17 patients with 47 titanium implants and 23 patients with 62 zirconia implants) was included. The primary aim of this survey was to assess the papillary fill (Jemt score). Additionally, further esthetic aspects were assessed. Papillae were fully present (Jemt score 3) around 39.1% of adjacent zirconia implants and 17.4% of adjacent titanium implants (p<0.01). The papilla deficit was significantly higher 1.64 mm (SD 1.35) around titanium compared to zirconia implants 0.92 mm (SD 0.94, p<0.01). The evaluation of the soft tissue recessions revealed no differences between implant materials, whereas titanium implants presented more visible implant shadows (p<0.01). Zirconia implants had more implants with papillae that filled the entire proximal space compared to titanium implants. Furthermore, titanium implants had a greater frequency of visible implant shadowing than the zirconia implants. Esthetic rules such as the interdental contact area and golden percentage rules did not differ significantly between the titanium and zirconia implants.

A 22-Year Follow Up of Immediate Implant Placement without Bone Augmentation: A Case Series Study

PURPOSE

To retrospectively evaluate the treatment outcome of immediate implants placed in fresh extraction sockets without bone augmentation after 22 years of function.

MATERIALS AND METHODS

The study group received implant therapy in 1997, including surgical placement and prosthodontic rehabilitation. The mean age of the subjects at the time of implant placement was 40 ± 5.54 years. A total of 35 subjects received 36 implants in fresh extraction sockets without bone augmentation. Definitive prostheses were placed 4 to 6 months after implant placement. Implant treatment outcomes were evaluated using clinical and radiographic parameters obtained during follow-up visits at 1, 5, 10, 15, 20, and 22 years after prosthetic loading.

RESULTS

Among the 35 treated subjects, five patients moved out of the country and could not be evaluated at the follow-up times. A total of 29 subjects were included in the study with a drop-out rate of 14.1%. Of these, one patient lost the implant during the osseointegration period before prosthodontic treatment. No other implant failure or complication during the rest of the follow-up period was reported, thus giving a cumulative survival rate of 97.2% during the 22-year follow-up. The change in marginal bone level was less than 2 mm in most subjects at the 22-year examination. The mean bone loss from baseline to 22-year follow-up was 1.61 mm, and the mean bone level at the 22-year follow-up examination was situated at 2.13 ± 0.023 mm from the implant platform, which was used as the reference point.

CONCLUSIONS

Immediate implant placement in extraction sockets exhibits excellent prognosis even when bone augmentation is not performed.

Peri-implant health

OBJECTIVE

The aim is to define clinical and histologic characteristics of peri-implant tissues in health and describe the mucosa-implant interface.

IMPORTANCE

An understanding of the characteristics of healthy peri-implant tissues facilitates the recognition of disease (i.e., departure from health).

FINDINGS

The healthy peri-implant mucosa is, at the microscopic level, comprised of a core of connective tissue covered by either a keratinized (masticatory mucosa) or non-keratinized epithelium (lining mucosa). The peri-implant mucosa averages about 3 to 4 mm high, and presents with an epithelium (about 2 mm long) facing the implant surface. Small clusters of inflammatory cells are usually present in the connective tissue lateral to the barrier epithelium. Most of the intrabony part of the implant appears to be in contact with mineralized bone (about 60%), while the remaining portion faces bone marrow, vascular structures, or fibrous tissue. During healing following implant installation, bone modeling occurs that may result in some reduction of the marginal bone level.

CONCLUSIONS

The characteristics of the peri-implant tissues in health are properly identified in the literature, including tissue dimensions and composition. Deviation from the features of health may be used by the clinician (and researcher) to identify disease, including peri-implant mucositis and peri-implantitis.

Patient-reported outcome measures focusing on aesthetics of implant- and tooth-supported fixed dental prostheses: A systematic review and meta-analysis

OBJECTIVES

The aim of this systematic review and meta-analysis was to summarize the existing evidence on patient-reported aesthetic outcome measures (PROMs) of implant-supported, relative to tooth-supported fixed dental prostheses.

MATERIAL AND METHODS

In April 2017, two reviewers independently searched the Medline (PubMed), EMBASE, and Cochrane electronic databases, focusing on studies including patient-reported aesthetic outcomes of implant- and tooth-supported fixed dental prostheses (FDPs). Human studies with a mean follow-up period of at least 1 year, a minimum of ten patients, and English, German, or French publication were included. For the comparison of subgroups, random-effects meta-regression for aggregate-level data was used.

RESULTS

The systematic search for implant-supported prostheses focusing on patient-reported outcomes identified 2,675 titles, which were screened by two independent authors. Fifty full-text articles were analyzed, and finally, 16 publications (including 19 relevant study cohorts) were included. For tooth-supported prostheses, no studies could be included. A total of 816 implant-supported reconstructions were analyzed by patients. Overall aesthetic evaluation by the patients' visual analogue scale (VAS) rating was high in implant-supported FDPs (median: 90.3; min-max: 80.0-94.0) and the surrounding mucosa (median: 84.7; min-max: 73.0-92.0). Individual restorative materials, implant neck design (i.e., tissue or bone level type implants), and the use of a fixed provisional had no effect on patients' ratings of the definitive implant-supported FDPs.

CONCLUSIONS

Aesthetics is an important patient-reported measure, which lacks in standardized methods; however, patients' satisfaction was high for implant- supported FDPs and the surrounding mucosa.

Etiology and classification of food impaction around implants and implant-retained prosthesis

BACKGROUND

Food impaction is a common risk factor for the initiation of peri-implant inflammation and failure of the osseointegrated implant. Although clinicians do acknowledge the presence of food impaction around implants and implant-retained prosthesis, no classification system has yet classified the food impaction around the implant and implant-retained prosthesis.

PURPOSE

The present paper aims to identify and classify the plausible etiology of food impaction around implants and implant-related prosthesis.

MATERIALS AND METHODS

The following search terms were utilized for data search: "Food Impaction" AND "Implants" AND "Food Impaction" AND "Perimplantitis" AND "Food Impaction" AND "Classification." Articles that were written in the English language in PubMed and Cochrane Library database from 1930 till September 2018 were scrutinized. A total of 24 articles were scrutinized, out of which only 15 articles were selected.

RESULTS

Food impaction around implants is broadly classified into five categories based on the number of implants, nature of implants prosthesis involved for replacement and relation of the implant prosthesis to the adjacent tooth, restoration, or prosthesis.

CONCLUSION

This is the first classification designed to classify food impaction around dental implants and implant-retained prosthesis. The classification can be used by clinicians for optimal diagnosis, interpretation, and treatment plan for patients.

Papilla height in relation to the distance between bone crest and interproximal contact point at single-tooth implants: A systematic review

OBJECTIVES

The aim of this systematic review was to investigate the tooth-implant papilla formation in correlation with the distance between the interproximal bone level and the prosthetic contact point.

MATERIAL AND METHODS

A comprehensive search of the current literature (01/01/2000-01/01/2017) was performed to identify human trials that included 10 patients or more, with at least 12 months follow-up, in need of the replacement of one single tooth in the anterior maxillary region with an implant-supported single crown. To meet the inclusion criteria, studies had to provide both radiographic and clinical data regarding the distance between the interproximal bone level and the prosthetic contact point.

RESULTS

The search yielded 136 records. After evaluation of abstracts and full texts, 12 papers were included in the final review, even though various reference points, for the comparison between the vertical distance and the papilla height, were used. The vertical distance between the interproximal bone level and prosthetic contact point ranged between 2 and 11 mm, and the partial or complete papilla fill (Jemt's score 2-3) ranged between 56.5% and 100% of cases.

CONCLUSION

There is limited evidence that the vertical distance from the base of the interproximal contact point to the crestal bone level seems to affect the interproximal papilla height; that is, the lower is the distance the higher is the percentage of papilla fill. Complete embrasure fill between an implant restoration and the adjacent tooth seems to be correlated with the integrity of the periodontal ligament of the tooth. To reduce the risk of aesthetic failures, interproximal probing on the adjacent teeth should be encouraged before implant placement.

Clinician assessments and patient perspectives of single-tooth implant restorations in the esthetic zone of the maxilla: A systematic review

STATEMENT OF PROBLEM

Esthetic outcomes associated with implant dentistry are important to both clinicians and patients. However, esthetic satisfaction may vary between the 2 groups. In order to evaluate the current publications relating to this topic, the following focused question was developed, "what are the quantitative and qualitative differences between clinician evaluations and patient perspectives in the assessment of single-tooth implant outcomes in the esthetic zone?"

PURPOSE

The purpose of this systematic review was to identify differences in esthetic satisfaction between clinicians and patients when evaluating single-tooth implant-supported restorations.

MATERIAL AND METHODS

An electronic search of the Medline database and Cochrane Central Register of Controlled Trials (2000 to 2014) was performed. The search was supplemented by a manual search of specific journals. A quality assessment of full-text articles was performed according to Cochrane Collaboration's tool and Newcastle-Ottawa scale for risk of bias assessment. Information regarding outcomes was collected and compared.

RESULTS

The search term combinations identified 555 titles. Subsequent to further review, 11 publications, including 2 randomized controlled trials, were selected for inclusion. Because of the heterogeneity of the study designs, study interventions, and esthetic assessment methods, no meta-analysis was performed. The clinicians identified a satisfactory outcome in 51% to 100% for peri-implant soft tissue and 62% to 90% for implant restorations. Patients showed a mean range score of 43% to 93% for peri-implant soft tissue and 81% to 96% for implant restorations. The visual analog scale score of the dentists was always lower than that of the patients. The review identified correlations between subjective and objective assessments for the Pink Esthetic Score (PES), the Papilla Index (PI), the Implant Crown Aesthetic Index (ICAI), and the modified (mod-ICAI) indices.

CONCLUSIONS

Clinicians are more critical of esthetic outcomes than patients. The PES and the PI correlated with the patients' responses concerning the peri-implant soft tissue. The ICAI and the mod-ICAI showed a correlation of both the peri-implant mucosa and implant-supported crown satisfaction. Thus, a comprehensive and practical index should be developed to assess the esthetic outcomes for single-tooth implant restorations in the esthetic zone.

Alterations of papilla dimensions after orthodontic closure of the maxillary midline diastema: a retrospective longitudinal study

PURPOSE

The aim of this study was to evaluate alterations of papilla dimensions after orthodontic closure of the diastema between maxillary central incisors.

METHODS

Sixty patients who had a visible diastema between maxillary central incisors that had been closed by orthodontic approximation were selected for this study. Various papilla dimensions were assessed on clinical photographs and study models before the orthodontic treatment and at the follow-up examination after closure of the diastema. Influences of the variables assessed before orthodontic treatment on the alterations of papilla height (PH) and papilla base thickness (PBT) were evaluated by univariate regression analysis. To analyze potential influences of the 3-dimensional papilla dimensions before orthodontic treatment on the alterations of PH and PBT, a multiple regression model was formulated including the 3-dimensional papilla dimensions as predictor variables.

RESULTS

On average, PH decreased by 0.80 mm and PBT increased after orthodontic closure of the diastema (P<0.01). Univariate regression analysis revealed that the PH (P=0.002) and PBT (P=0.047) before orthodontic treatment influenced the alteration of PH. With respect to the alteration of PBT, the diastema width (P=0.045) and PBT (P=0.000) were found to be influential factors. PBT before the orthodontic treatment significantly influenced the alteration of PBT in the multiple regression model.

CONCLUSIONS

PH decreased but PBT increased after orthodontic closure of the diastema. The papilla dimensions before orthodontic treatment influenced the alterations of PH and PBT after closure of the diastema. The PBT increased more when the diastema width before the orthodontic treatment was larger.

Dimensions of the healthy gingiva and peri-implant mucosa

OBJECTIVE

To determine the dimensions of the soft tissue cuff present at various aspects of teeth and to compare these dimensions to those of the mucosa surrounding single implants.

MATERIAL AND METHODS

Fifty volunteers were recruited that were ≥25 years of age and exhibited no signs of (i) untreated caries; (ii) loss of periodontal tissue support in the incisor, canine, and premolar regions; (iii) systemic or local disease. Furthermore, among the 50 patients recruited (iV), 27 had one single implant in the maxilla with teeth present mesial and/or distal to the implant. Probing pocket depth (PPD) and transmucosal sounding depth (TS) were assessed by five experienced, carefully calibrated examiners and with the use of a periodontal probe at the proximal (mesial, distal) and flat (facial, buccal and palatal/lingual) surfaces of all teeth/implants. The width of the keratinized mucosa (KM) was also determined.

RESULTS

It was demonstrated that (i) PPD and TS were greater at proximal than at flat surfaces at both tooth and implant sites. In addition, both PPD and TS were deeper at implant than at tooth sites. The TS values documented that the cuff of healthy soft tissue that surrounded a tooth varied between 2 mm at flat surfaces and 4 mm at proximal surfaces, while at implant sites, the mucosa at proximal as well as flat surfaces was 1-1.5 mm greater.

CONCLUSION

The probing pocket depth (PPD) and the transmucosal sounding depth (TS) values were greater at proximal than at flat, that is, facial/palatal (lingual) surfaces at tooth sites and frequently also at implant sites. Furthermore, the PPD and the TS dimensions were greater at implant than at adjacent tooth sites.