Soft Tissue Changes Around Immediately Placed Implants: A Systematic Review and Meta-Analyses With at Least 12 Months of Follow-Up After Functional Loading

Prosthetic Soft Tissue Management in Esthetic Implant Restorations, Part I: Presurgical Planning, Implant Placement, and Restoration Timing. A Narrative Review

OBJECTIVES

This two-part review article delineates various techniques to enhance esthetic outcomes in anterior implant treatments. Part I concentrates on presurgical measures, case selection, implant placement, and restoration timing. Part II discusses post-surgical steps, the temporary restoration phase, the emergence profile contour, abutment types, and impression techniques.

MATERIAL AND METHODS

A comprehensive search was conducted using Medline/PubMed, Embase, Scopus, and the Cochrane Library. The primary keywords included were "Dental Implants," "Dental Prosthesis, Implant-Supported," "Esthetics, Dental," "Dental Impression Techniques," and "Tissue Management."

RESULTS

Initially, 1472 studies were identified, from which 187 were selected based on publication year and title relevance. After removing duplicates, 84 abstracts were reviewed in full text, culminating in 59 studies being thoroughly analyzed.

CONCLUSIONS

Optimal esthetics in implant restorations are attainable through meticulous treatment planning, precise surgical execution, and systematic restorative steps, ensuring predictable outcomes. Factors such as a thick gingival biotype, an intact facial bone wall, and atraumatic extraction significantly contribute to superior esthetic results. Immediate implant placement combined with immediate provisionalization provides the most predictable outcomes by supporting and maintaining soft tissue architecture. Conversely, delayed implant placement and provisionalization often require extensive manipulation of collapsed soft tissues to achieve desired esthetics.

Effect of soft tissue volume on midfacial gingival margin alterations following immediate implant placement in the esthetic zone: a 1-year randomized clinical and volumetric trial

BACKGROUND

The current trial evaluated the midfacial gingival margin changes, volumetric, radiographic and clinical alterations 1-year following immediate implant placement with customized healing abutment (IIP + CHA) either solely, or in combination with xenograft (IIP + Bonegraft) or with connective tissue grafting (IIP + CTG) at sites with thin labial bone in the esthetic zone.

METHODS

Thirty-nine non-restorable maxillary teeth indicated for extraction in the esthetic zone were included. Participants were randomly assigned into three equal group; IIP + Bonegraft (Control), IIP + CTG and IIP + CHA. Midfacial gingival margin changes(mm) as primary outcome, labial soft tissue contour change(mm), interdental tissue height changes and total volume(mm3) were assessed. Amount of bone labial to the implant and crestal bone level changes were also recorded. All outcomes were measured 1-year post-operative.

RESULTS

The midfacial gingival margin changes demonstrated a significant difference (P ≤ 0.05) between the groups showing -0.98, -0.74 and -1.54 mm in sites treated with IIP + Bone graft, IIP + CTG and IIP + CHA respectively after1-year. While labial soft tissue contour change (mm), total volume (mm3) and distal interdental tissue height changes (mm) revealed a significant difference after one-year between the studied groups, yet mesial interdental tissue height changes showed no difference (P > 0.05). Both IIP + Bone graft and IIP + CHA groups revealed a significant positive correlation between the total volume loss (mm3) after 1 year and mid-facial gingival margin changes (P ≤ 0.05). However, no significant correlation was observed in the IIP + CTG group (P = 0.63). CBCT measurements showed a significant difference in crestal bone changes between the three groups (P ≤ 0.05), yet, there was no significant difference regarding mean amount of bone labial to the implant(P > 0.05).

CONCLUSIONS

This investigation suggests that the mere presence of CTG simultaneous with IIP in the anterior maxilla reduced the midfacial gingival margin alterations (mm), besides, CTG decreased the overall volume loss (mm3) by 5-folds compared to the other studied groups after one year. Meanwhile, using CHA alone with IIP failed to maintain the peri-implant soft tissues contour.

TRIAL REGISTRATION

The current trial was retrospectively registered at Clinical trials.gov (ID: NCT05975515, Date: 27-July-2023).

Relationship between soft tissue dimensions and tomographic radial root position classification system for immediate implant installation

The aim of this study was to evaluate the relationship between soft tissue dimensions and radial root position (RRP) classification for immediate implant placement on maxillary anterior teeth. Maxillary anterior teeth (n = 420) were analyzed in the radial plane of cone beam computed tomography (CBCT) scans. Each tooth was classified according to its RRP: class I, (IA, IB); class II (IIA, IIB) class III; class IV, and class V. Soft tissue thickness at different landmarks, supracrestal soft tissue height, and crestal bone thickness were measured in CBCT. Keratinized tissue width was clinically measured. Gingival phenotype (thick or thin) was evaluated by transparency of the periodontal probe and at the landmark 2 mm from the gingival margin in CBCT. Class I tooth position accounted for 31.7%, class II for 45%, class III for 13.3%, class IV for 0.5%, and class V for 9.5%. The gingival phenotype was associated with RRP (χ2 test, p < 0.05). Soft tissue dimensions were significantly different over RRP classes (ANOVA and Tukey tests, p < 0.05). Types IA and IIA presented both thick soft and hard tissues. When planning immediate implants in the anterior maxilla, soft tissue dimensions evaluation should be incorporated into RRP classification to increase the accuracy and predictability of treatment outcomes.

A comparison of alveolar ridge mucosa thickness in completely edentulous patients

PURPOSE

The purpose of this cross-sectional clinical study was to determine and compare alveolar ridge mucosa thickness at crestal, buccal, and lingual locations of the maxillary and mandibular arches in completely edentulous patients using a dedicated, ultrasonic gingival scanner.

MATERIALS AND METHODS

Thirty-eight completely edentulous subjects were included in the study. In each subject, soft tissue thickness was measured at 28 sites of the edentulous ridge by a single calibrated examiner. Intra-observer reliability was calculated with Intraclass Correlation Coefficients by measuring 10 subjects twice, after 1 week. Measurements (mm) were taken at the buccal, lingual, and crestal aspects of the ridge with a dedicated ultrasonic scanner. Repeated measures ANOVA and paired t-tests were used to compare the mean buccal, lingual, and crestal soft tissue thicknesses at each site. The Generalized Estimating Equations model was used to study the effects of age, sex, and race. Confidence level was set to 95%.

RESULTS

Mean tissue thickness ranged from 0.96  to 1.98 mm with a mean of 1.63 ± 0.25 mm. Intraclass Correlation Coefficients were > 0.97. No significant differences between buccal, crestal, and lingual sites were noted for the mandibular arch as well as at 4 sites on the maxillary arch (maxillary right second molar, maxillary right canine, maxillary left first premolar, maxillary left second molar). However, significant differences in soft tissue thickness were noted for all remaining maxillary sites. Race was found to be positively correlated with tissue thickness, with Black individuals showing a significantly greater thickness than White individuals at 4 sites (maxillary right first molar, maxillary left canine, mandibular right second premolar, mandibular right first molar). Age was found to be positively correlated with tissue thickness at 4 sites (maxillary left central incisor, maxillary left first molar, maxillary left second molar, mandibular left second premolar) and negatively correlated at 2 sites (mandibular right canine, mandibular right second molar). Female sex was positively (maxillary left second premolar, maxillary left second molar) and negatively (mandibular right canine) correlated, respectively, with tissue thickness at 3 sites. When data for anterior and posterior sites were respectively pooled, tissue thickness was significantly less at anterior sextant lingual and crestal sites, while no difference was seen for buccal sites.

CONCLUSION

Statistically significant differences for alveolar ridge mucosa thickness were found at several sites in the maxilla and between anterior and posterior sextants for lingual and crestal sites in the maxillary and mandibular arches. Tissue thickness differences were also noted for race with Black individuals showing greater tissue thickness at some sites. Age and sex did not show a clear effect on tissue thickness. Recorded differences in tissue thickness were however small and appear of uncertain clinical significance.

The soft tissue esthetic outcome with and without immediate provisionalization in immediate implants: A systematic review and meta-analysis

Aim

This systematic review and meta-analysis aimed at checking influences of immediate provisionalization on the primary esthetic outcome by Pink Esthetic Score (PES) as well as other secondary soft tissue outcomes such as bleeding on probing, probing depth, plaque index, mesial papillary recession, distal papillary recession, and midfacial mucosal recession of the peri-implant mucosa around immediately placed implants in the anterior maxilla.

Setting and Design

This systematic review and meta-analysis was evaluated using the Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines.

Materials and Methods

The relevant studies were found in the databases such as MEDLINE (PubMed), the Cochrane Central Register of Controlled Trials, Science Direct, and Google Scholar. The search was restricted to studies published in English only, with no time constraints. A second hand search was conducted on individual journals and study reference lists. The Evidence Project risk-of-bias tool was used to assess the risk of bias in included studies. The level of evidence was determined using the GRADEpro GDT: GRADEpro Guideline Development Tool (software). McMaster University, 2020 (developed by Evidence Prime, Inc.,).

Statistical Analysis Used

The statistical meta-analysis was conducted by using Review Manager (RevMan) (Computer Program). Version 5.4. Copenhagen: The Nordic Cochrane Centre, the Cochrane Collaboration, 2020.

Results

Nine studies were finalized. Seven studies were selected out of nine in the meta-analysis for PES. The results of the current meta-analysis for primary outcome observed that immediate implant placement (IIP) followed by immediate provisionalization improves the esthetic outcome, with forest plot favoring immediate provisionalization and demonstrating a statistically significant difference (mean difference [MD] =1.54, [95% confidence interval (CI): 0.82-2.27], P < 0.0001). Statistically insignificant result was observed for secondary outcomes; bleeding on probing (MD = 4.00, [95% CI: -1.15-9.15], P = 0.13), probing depth (MD = 0.17, [95% CI: -0.13-0.48], P = 0.26), plaque index (MD = -1.00, [95% CI: -7.56-5.56], P = 0.77), mesial papillary recession (MD = -0.10, [95% CI: -0.31-0.10], P = 0.33), midfacial mucosal recession (MD = -0.47, [95% CI: -1.01-0.07], P = 0.09). However, for distal papillary recession (MD = -0.32, [95% CI: -0.50--0.13], P = 0.0007), the result was statistically significant with forest plot favoring immediate provisionalization.

Conclusion

When the implant is placed in the esthetic zone, IIP with immediate provisionalization provides the best gingival (pink) esthetics.

Effect of customized healing abutments on the peri-implant linear and volumetric tissue changes at maxillary immediate implant sites: A 1-year prospective randomized clinical trial

BACKGROUND

Immediate implant placement (IIP) associated with the use of bone substitutes and collagen matrices (CM) seems to reduce the amount of resorption at peri-implant areas. Recently, customized healing abutments (CA) appeared as another solution in order to seal the socket and preserve the original soft tissue contour.

PURPOSE

To evaluate peri-implant tissues dimensional changes after using customized healing abutments compared with the use of xenogeneic collagen matrices as socket sealing options in flapless maxillary immediate implant placement.

MATERIAL AND METHODS

The present study was designed as a prospective, randomized, controlled clinical trial. Patients were allocated into two groups depending on the socket sealing option: in the CM group a collagen matrix was used and in the CA group a customized abutment. Digital impressions were taken prior to extraction, 1, 4, and 12 months after implant insertion and the digital files allowed to evaluate linear buccal changes (MBC) and the buccal volumetric variation (BVv) between the different time points at peri-implant tissue areas. Additionally, mucosa variation was computed assessing the papilla presence and the midfacial mucosa height. Statistical significance was set at 0.05.

RESULTS

Twenty-eight patients were observed during a 12-month period. Significant differences between mean values of BVv at the first month were observed at the CM and CA group (-9.75 ± 6.65% and -4.76 ± 5.29%, respectively) (p = 0.043). At the 1-year follow-up, no significant differences were found in terms of BVv between the two groups, although the thin bone phenotype (≤1 mm) significantly influenced the volumetric variations that occurred in each group. No significant differences were noticed in midfacial mucosa and papillae alteration between groups, after 1 year of treatment.

CONCLUSION

Both treatment options are predictable solutions for socket sealing in IIP, although a higher volumetric variation can be expected in the presence of thin bone phenotypes.

Facial mucosal level of single immediately placed implants with either immediate provisionalization or delayed restoration: An intermediate-term study

BACKGROUND

Immediately placed single implants with either immediate provisionalization (test) or delayed restoration (control) were followed for up to 1 year in our previous randomized clinical trial. Peri-implant tissues continue to remodel after implants are in function. Therefore, the primary aim of this study was to evaluate the facial mucosal level changes in the intermediate term between the two groups and to study potential factors influencing the mucosal level change.

METHODS

Patients who had already completed the previous clinical trial by receiving a single immediately placed implant were re-invited to this study. The facial mucosal level as well as the other peri-implant hard and soft tissue dimensions and conditions were measured clinically, radiographically and with ultrasound. These data were compared between the test and control implants. The mucosal level change as the function of the final crown contour, measured as the abutment-crown angle (ACA), was estimated with a linear regression model.

RESULTS

Twenty-eight patients (n of test/control = 16/12) with a mean 30-month follow-up were recruited. The mean mucosal level change was -0.38 mm (control) and 0.06 mm (test), without statistical difference between the two groups. The other clinical, radiographic, and ultrasound parameters were not statistically different. ACA was statistically significant associated with the recession (P = 0.02). The estimate effect was 0.25 mm per 10° increase (adjusted R²  = 0.18; 95% CI, 0.02 to 0.49 mm). After adjusting for vertical implant position, implant abutment angle and the group, the effect became borderline significant (P = 0.09).

CONCLUSIONS

Peri-implant tissues, including the mucosal level change of immediately placed implants with either immediate provisionalization or delayed restoration remained stable and did not differ between the groups in the intermediate term. The final crown angle, influenced by implant position and abutment angle, might be associated with mucosal margin level change.

Immediate implant placement with or without connective tissue graft: A systematic review and meta-analysis

OBJECTIVES

To assess the effect of connective tissue graft (CTG) in terms of vertical mid-facial soft tissue change when applied at the buccal aspect following single immediate implant placement (IIP).

MATERIALS AND METHODS

Two independent reviewers conducted an electronic literature search in PubMed, Web of Science, EMBASE and Cochrane databases as well as a manual search to identify eligible clinical studies up to January 2020. Randomized controlled trials (RCTs) and non-randomized controlled studies (NRSs) comparing IIP with CTG and without CTG over a mean follow-up of at least 12 months were included for a qualitative analysis. Meta-analyses were performed on data provided by RCTs.

RESULTS

Out of 1814 records, 5 RCTs and 3 NRSs reported on 409 (IIP + CTG: 246, IIP: 163) immediately installed implants with a mean follow-up ranging from 12 to 108 months. Only 1 RCT showed low risk of bias. Meta-analysis revealed a significant difference in terms of vertical mid-facial soft tissue change between IIP + CTG and IIP pointing to 0.41 mm (95% CI [0.21; 0.61], p < .001) in favour of soft tissue grafting. This outcome was clinically relevant since the risk for ≥1 mm asymmetry in mid-facial vertical soft tissue level was 12 times (RR 12.10, 95% CI [2.57; 56.91], p = .002) lower following IIP + CTG. Soft tissue grafting also resulted in a trend towards less bleeding on probing (MD 17%, 95% CI [-35%; 1%], p = .06). Meta-analyses did not reveal significant differences in terms of pink aesthetic score, marginal bone level change and probing depth. Results were inconclusive for horizontal mid-facial soft tissue change and papilla height change. Based on GRADE guidelines, a moderate recommendation for the use of a CTG following IIP can be made.

CONCLUSION

CTG contributes to mid-facial soft tissue stability following IIP. Therefore, CTG should be considered when elevated risk for mid-facial recession is expected in the aesthetic zone (thin gingival biotype, <0.5 mm buccal bone thickness).

Contour Changes Following Immediate Placement of Ultra-Wide Implants in Molar Extraction Sockets without Bone Grafting

The aim was to evaluate ridge reduction and mucosal recession following immediate placement of ultra-wide implants in molar sockets, without bone grafting. Impressions were taken prior to tooth extraction, 4 months and 1 year after implant placement. The casts were digitized and compared. Mucosal recessions and horizontal ridge reduction were measured. A total of 16 implants were in the maxilla and 11 in the mandible. At the buccal aspect, there was a mean reduction of 0.94 mm after 4 months and 0.89 mm after one year (p = 0.933). At the palatal/lingual aspect, this was 1.09 mm after 4 months and 0.69 mm after 1 year (p = 0.001). After 1 year, a recession of 0.59 mm was measured at the zenith, 1.04 mm at the mesial and 0.98 mm at the distal papilla. The mean midfacial horizontal ridge reduction was 1.23 mm after 4 months and 1.45 mm after 1 year. At the midpalatal/midlingual aspect, the mean horizontal reduction was 1.43 mm after 4 months and 1.16 mm after 1 year. Immediate implant placement without bone grafting in the posterior jaw yields a significant horizontal ridge reduction and minor mucosal recession. Clinicians should anticipate the amount of ridge reduction and consider augmentation at the time of implant placement.

Influence of the implant-abutment connection on the ratio between height and thickness of tissues at the buccal zenith: a randomized controlled trial on 188 implants placed in 104 patients

Background

To compare tissue response to two implant systems, featuring internal hexed connections with different designs.

Methods

Patients enrolled in this randomized controlled trial were assigned to two groups. In Group 1, patients were treated with implants with a 5° conical internal hexed connection (Anyridge®, MegaGen, South Korea). In Group 2, patients were treated with implants with an internal hexed connection (Core®, Kristal, Italy). After implant placement and a provisionalisation period of 12 months, impressions were taken, stone casts were poured and digitised with a desktop scanner (D700®, 3Shape, Copenhagen, Denmark). In a digital environment, for each fixture, two values were collected at the buccal zenith: the height of the peri-implant mucosa (mucosal height; MH), calculated from the vestibular shoulder of the implant analogue to the upper gingival margin of the supra-implant tissue; and the width of the peri-implant mucosa (mucosal thickness; MT), calculated from the vestibular shoulder of the analogue to the external mucosa point perpendicular to the implant major axis. The mean and standard deviation for MH and MT, as well as their ratios, were calculated for each group; the sectors in which the implants were placed were also considered. Finally, correlation between MH, MT, connection type and sector was assessed by Pearson’s correlation coefficient, with significance level set at 0.05, and a confidence interval (CI) set at 95%.

Results

Data deriving from 188 implants placed in 104 patients were evaluated. The mean MH values were 3.32 (± 0.12) and 2.70 (± 0.16) mm for Groups 1 and 2, respectively. The mean MT values were 4.37 (± 0.16) and 3.93 (± 0.18) mm for Groups 1 and 2, respectively. Group 1 showed higher MH and MT values and a better ratio (1.50 ± 0.88) than Group 2 (1.81 ± 1.20). The MH, MT and MH/MT ratio were significantly influenced both by sector (p = 0.015) and group (p = 0.047).

Conclusions

Within the limits of this study, the 5° connection implants supported a more extended tissue height and thickness at the buccal zenith, and a better ratio between them.

Trial registration

This study was retrospectively registered in Clinicaltrials.gov, with number NCT04160689, dated 13/11/2019.

The two-dimensional size of peri-implant soft tissue in the anterior maxilla and some relevance: A 1- to 7-year cross-sectional study

AIM

This study measured the two-dimensional size of soft and hard tissues and analysed some relevance between them.

MATERIAL AND METHODS

Ninety-six maxillary anterior implants with a follow-up time 1-7 years postoperatively were evaluated. We superimposed the CBCT data of 72 patients with the optical scan data, followed by the measurements of the thickness and the height of soft and bone tissues. The shoulder of the implant was the reference point for all vertical measurements.

RESULTS

At the level of implant shoulder, the mid-buccal mean thickness of soft tissue was 1.83 ± 0.76 mm, and on the palatal side, it was 4.00 ± 1.22 mm. The mean height of mid-buccal and mid-palatal gingiva was 4.16 ± 1.07 mm and 4.27 ± 1.07 mm. The buccal and palatal vertical bone wall peak was 0.41 ± 0.73 mm and 0.22 ± 0.57 mm coronal to the implant shoulder, and the marginal bone loss was -0.28 ± 0.76 mm and -0.84 ± 1.41 mm. Correlation analysis showed that the soft tissue thickness was negatively correlated with the bone thickness at 0 mm on the buccal side and at 0/2/4 mm on the palatal side apical towards from implant shoulder. The gingival height was significantly positively correlated with bone peak height and marginal bone height.

CONCLUSION

Soft and hard tissues were basically negatively correlated in the horizontal direction. Sites with little marginal bone loss or high bone peak positively correlated with higher soft tissue levels.

Deproteinized bovine bone mineral is non-inferior to deproteinized bovine bone mineral with 10% collagen in maintaining the soft tissue contour post-extraction: A randomized trial

OBJECTIVES

To test the non-inferiority of demineralized bovine bone mineral (DBBM) compared to demineralized bovine bone mineral with 10% collagen (DBBM-C) for the maintenance of the soft tissue contour after tooth extraction in the esthetic zone.

MATERIAL AND METHODS

Sixty-five patients randomly received ridge preservation at a single site in the anterior maxilla with DBBM or DBBM-C. Both, DBBM and DBBM-C, were covered with a collagen matrix. Profilometric analyses were performed at baseline (BL), immediately after treatment (PO), and at 4 months (FU; day of implant placement). The main outcome was the horizontal mean change (HC) at the buccal aspect. The measurements also included changes of the estimated soft tissue thickness (eTT) at 1, 3, and 5 mm below the buccal gingival margin. Descriptive analysis was performed, and differences between groups were analyzed using independent samples t test. The non-inferiority test was performed for HC.

RESULTS

At 4 months, the horizontal mean change (HC) was -1.43 mm (±0.53 mm) (DBBM-C) and -1.32 mm (±0.53 mm) (DBBM). Change of the estimated soft tissue thickness (eTT) between baseline (BL) and four months of follow-up (FU) at 1, 3, and 5 mm amounted to -4.58 mm (±2.02 mm), -2.40 mm (±0.97 mm), and -1.37 mm (±0.78 mm) for DBBM-C and to -4.12 mm (±1.80 mm), -2.09 mm (±0.91 mm), and -1.23 mm (±0.72 mm) for DBBM. The differences between the groups were not statistically significantly for any of the outcome measures (p > .05).

CONCLUSIONS

DBBM is non-inferior to DBBM-C for the maintenance of the soft tissue contour 4 months after tooth extraction.

Standard vs customized healing abutments with simultaneous bone grafting for tissue changes around immediate implants. 1-year outcomes from a randomized clinical trial

BACKGROUND

Immediate implants have shown risks of esthetic complications. The hypothesis was that a customized healing abutment could improve the peri-implant tissue healing.

PURPOSE

To evaluate and compare the soft and hard tissue healing around immediate implants that received bone grafting and a customized vs a standard healing abutment.

MATERIALS AND METHODS

Patients, who required tooth extraction and who received an immediate implant (with an alloplastic graft material) were randomly assigned to a customized or a standard healing abutment group. Clinical and radiographic examinations were taken at baseline, at 4 and 12 months.

RESULTS

Twenty-five patients out of 61 were excluded from the study because unsuitable for immediate implantation. In total, 36 patients were randomized in the two groups. There were 17 females and 19 males (age range 23-77). No prosthetic or implant failure was registered during the study period. The Papilla Index was significantly higher in the customized than in the standard group at 4 and 12 months (P = .0002). The bone loss at mesial sites was significantly higher in the control than in the test group (P = .0014).

CONCLUSION

The customized healing abutment group showed the most favorable outcomes (in terms of PI and MBL) in case of immediate implant that received a peri-implant bone grafting procedure.

Making the Best Clinical Decisions for Patients: The Pros-CAT ProtocolTM

The Pros-CAT protocol critical appraisal method uses accepted strategies to identify and summarize best evidence to support patient care through evidence-based analysis that includes assessing the patient; developing a concise clinical question; conducting a literature search to identify pertinent research; critically appraising the identified literature for validity, reliability, and applicability to the patient situation; synthesizing the literature into a meaningful conclusion using an organized method; and applying that synthesis to the patient's need. The Pros-CAT protocol is applicable for practicing clinicians, dental students, postgraduate students, and residents. The Pros-CAT index compares evidence strength for patient applicability.

The association between gingival recession and buccal bone at maxillary anterior teeth

BACKGROUND

Gingival recession and a thin or absent buccal plate occur frequently at maxillary anterior teeth and necessitate careful treatment planning to prevent future complications. However, the association between these two conditions is unclear and the ability of gingival recession to predict underlying buccal bone deficiencies is unknown. Therefore, the aim of this study is to use clinical and radiographic data to test this association and determine the influence of demographic and clinical parameters on both conditions.

METHODS

This investigation comprised a single-center, retrospective study. Data were derived from periodontal examinations performed on 66 adult subjects. Corresponding cone-beam computed tomography images were used to measure the width of buccal bone at two points along the root surface and the distance between the bone crest and cemento-enamel junction (CEJ). Results were then analyzed to determine the association between the presence of gingival recession and the condition of radiographic buccal bone, as well as the relative contribution of demographic parameters and other clinical findings to gingival recession and buccal bone conditions.

RESULTS

Gingival recession was present at 32.9% of maxillary anterior teeth and was most common at canines, followed by lateral incisors and central incisors. Mean buccal bone widths were significantly less, and the distance between the CEJ and bone crest was significantly greater for teeth with recession. Accordingly, gingival recession was a significant predictor for buccal bone thickness <1 mm at the level of 4 mm apical to the CEJ (odds ratio 2.733, 95% confidence interval 1.644 to 4.543, P < 0.0001). Probing depths were related to the presence or absence of gingival recession, while patient sex, age, and the apico-coronal height of the gingiva were related to buccal bone thickness.

CONCLUSION

Within the limitations of this study, maxillary anterior teeth with pre-existing gingival recession were more likely to have thin (<1 mm) buccal bone.

Interim tissue changes following connective tissue grafting and two-stage implant placement. A randomized clinical trial

AIM

To determine tissue changes at implants placed either conventionally or in combination with a connective tissue graft (CTG).

MATERIALS AND METHODS

Forty-eight partially edentulous subjects were randomized into two treatment Groups, and 46 completed the study. Group-A (N_A   = 23) received crestal implant placement. In Group-B (N_B   = 23), a CTG harvested from the palate was stabilized over the implant neck. At the time of implant placement (T0), Groups were categorized as having thin mucosa ≤ 2.5 mm at the surgical site (N_{S ubgroup- AI}   = 12, N_{S ubgroup- BI}   = 11) or thick mucosa > 2.5 mm (N_{S ubgroup- AII}   = 11, N_{S ubgroup- BII}   = 12). Mucosa thickness, width of keratinized tissue (WKT), crestal bone levels and relative bone thickness were determined at T0 and at the two-stage surgery (T1).

RESULTS

At T1, on the alveolar crest, mucosa thickness significantly decreased in the thick mucosa Subgroups (-AII/-BII, both p = 0.001), but increased at thin mucosa grafted sites (p = 0.049). No significant changes were noted in the WKT for either group. Thin mucosa grafted Subgroups (-AI/-BI) demonstrated significant decreases in crestal bone levels (both p ≤ 0.008). Crestal relative bone thickness decreased in all Subgroups (p ≤ 0.027 for significant changes).

CONCLUSIONS

Connective tissue grafting resulted in smaller reductions of mucosa thickness on the alveolar crest and appeared to have the greater effects at sites with initially thin mucosa.

Systematic review versus structured critical analysis

Objective: This analysis discusses common problems with systematic reviews (SRs) and presents a novel solution, the structured critical analysis (SCA) that can be incorporated into a SR or used as an alternative literature review design.Methods: A cross-sectional survey of current SRs related to interdisciplinary restorative dentistry was obtained by evaluating 100 current SRs for their self-reported methodological quality and its effect on scientific validity.Results: The preferred reporting items for systematic reviews and meta-analyses protocol (PRISMA) was used in 99/100 SRs, but only 8/100 reported a low risk of bias. High statistical heterogeneity precluding meta-analysis was found in 44/100 SRs. Only 94 paragraphs/100 SRs provided critical analysis.Discussion: Significant problems were found with current SRs that can compromise their reliability as the premier level of evidence for clinical science research. The reader must be aware of these deficiencies to correctly interpret the SR and cannot rely on the format alone.

Safety and efficacy of a novel, gradually anodized dental implant surface: A study in Yucatan mini pigs

BACKGROUND

A newly developed dental implant system combining advancements in surface chemistry, topography, nanostructure, color, and surface energy aims to address biological challenges and expand clinical applications.

PURPOSE

To assess the short- and long-term safety and efficacy of a novel, gradually anodized dental implant surface/anodized abutment.

MATERIALS AND METHODS

Twenty-four Yucatan mini pigs (20-24 months old) received two dental implants in each jaw quadrant. Each site was randomized to receive either a commercially available anodized implant/machined abutment or a gradually anodized implant/anodized abutment with a protective layer. Animals were euthanized at 3, 6, and 13 weeks. Microcomputed tomography and histological analyses were performed.

RESULTS

No significant histological differences in inflammation scores, epithelium length, bone-to-implant contact, or bone density were observed between groups for any healing time. Mucosal height was significantly higher at 3 weeks for controls (Δ = 0.2 mm); no differences were observed at 6 and 13 weeks. No significant differences in radiographic bone volume, bone-to-implant contact, trabecular thickness, and crestal bone levels were observed, irrespective of healing time. Trabecular spacing was borderline significant at 3 weeks in favor of the test implant sites; no differences were observed at 6 weeks. No significant differences were observed between experimental groups at 13 weeks.

CONCLUSIONS

The new implant system yielded results comparable to a commercially available predicate device.

Effect of guided bone regeneration on immediately placed implants: Meta-analyses with at least 12 months follow up after functional loading

INTRODUCTION

Immediate implant placement (IIP) into fresh extraction socket is a favorable treatment option. If successfully managed, it reduces the overall treatment time, and increases patient's satisfaction. Surgical and restorative factors affect IIP success rates. In this systematic review we evaluate the effect of guided bone regeneration (GBR) at the time of IIP on crestal bone level (CBL) changes after at least 12-months of functional loading.

METHODS

Reviewers conducted an independent search of the National Center for Biotechnology Information PubMed, Medline, and the Cochrane Collaboration Library from 1966 to January 2017 following the inclusion criteria. A hand search of bibliographies of reviews and clinical trials related to IIP was also performed. This study looked into CBL changes around IIP primarily and further extracted the data to conduct three meta-analysis of "IIP using GBR versus IIP without GBR", "IIP using bone graft alone versus IIP using bone graft with membrane" and "IIP using GBR versus conventional implant placement" which were further subdivided to provide more detailed information for each. Four reviewers independently assessed the study data and methodologic quality using data extraction and assessment forms.

RESULTS

The electronic search identified 714 potential studies and the hand search retrieved 55 studies. Crestal bone level (CBL) changes were determined in three meta-analyses. The results revealed a mean difference in CBL changes of 0.179 ± 0.174 mm  in favor of IIP without GBR when compared with implant with GBR. However, IIP with bone graft and membrane showed better results when compared with IIP with bone graft alone [CBL changes of 0.532 ± 0.572 mm]. CBL preservation was noted in IIP with GBR versus conventional implant placement [CBL changes of - 0.001 ± 0.049 mm].

CONCLUSIONS

Meta-analyses showed minimal difference in CBL around IIP with bone graft versus without bone graft and with IIP with GBR compared with conventional implant placement. However, IIP with bone graft and membrane reported better CBL preservation compared with IIP with bone graft alone. Nonetheless, these results should be interpreted with caution because of moderate heterogeneity between studies.

A prospective study on ultra-wide diameter dental implants for immediate molar replacement

BACKGROUND

Although wide diameter implants are well documented, little is known about ultra-wide diameter implants (>6 mm). This study evaluates the clinical outcome of ultra-wide diameter implants, placed in molar extraction sockets.

MATERIALS AND METHODS

Ultra-wide diameter implants (7-9 mm) were placed immediately after molar extraction in a 1-stage protocol, without raising a flap or using any bone grafts. After 4 months, the implant was loaded with a single screw-retained crown. Bone loss was evaluated using peri-apical radiographs. Plaque and bleeding were recorded. Crown and papilla dimensions were measured and compared with the contra-lateral tooth.

RESULTS

Fifty-one patients (36 male and 15 female), mean ages 61 years old, were treated with 26 implants in the maxilla and 25 implants in the mandible. The majority had a thick (#19) or medium (#31) biotype. After a mean-follow-up period of 23 months, the mean bone level was located 1.16 mm apical of the implant-abutment junction (SD 0.42, range 0.00-2.45) while the actual bone remodeling associated with socket healing resulted in a mean coronal movement of the bone level of 0.15 mm. The mean insertion torque was 116 Ncm (SD 53, range 10-250). There were no differences in papilla height (P = .55), crown length (P = .32), zenith (P = .84), and bucco-palatal dimensions (P = .38). There was a significant difference in the mesio-distal dimension (P = .01). Mean probing depth was 2.59 mm at the implant and 2.23 mm at the contra-lateral tooth (P = .001). There was significantly more plaque at the tooth compared to the implant (P = .01), but there was no significant difference in terms of bleeding on probing (P = .08). Patient satisfaction was high with 72.5% of the patients experiencing no problems at all.

CONCLUSIONS

Ultra-wide diameter implants have a predictable outcome, demonstrating very little bone loss. Papilla and crown dimensions were comparable to the contra-lateral natural tooth.

Influence of soft tissue grafting, orofacial implant position, and angulation on facial hard and soft tissue thickness at immediately inserted and provisionalized implants in the anterior maxilla

BACKGROUND

Resorption of hard and soft tissues following immediate implant insertion is frequently reported. Data regarding the influencing factors on facial tissue thickness are rare.

PURPOSE

This retrospective study investigated the impact of connective tissue grafting, the orofacial angulation and position of immediately inserted and provisionalized implants on the facial hard and soft tissue thickness in the anterior maxilla within a 1- to 5-year follow-up.

MATERIAL AND METHODS

Implants with the prerequisite of having preoperative and postoperative cone beam computed tomography (CBCT) and a follow-up of 1 to 5 years were included. Facial bone deficiencies were grafted flaplessly with autogenous bone in all sites. In a subgroup of implants additional connective tissue grafting was performed, whereas the remaining implants were not grafted with soft tissue. The orofacial tooth and implant angulation, the change of horizontal position and the facial bone thickness were measured by CBCT, the facial mucosa thickness by an ultrasonic device.

RESULTS

In total, 76 implants were placed in 55 patients. Sixty-nine sites showed a facial bone defect. Thirty-eight received a connective tissue graft additionally. All implants were still in function after a mean follow-up of 36 months. The mean thickness of the facial mucosa was 1.72 mm at 1 mm, 1.63 mm at 4 mm, 1.52 mm at 6 mm, and 1.66 mm at 9 mm apically to mucosal margin. The bone thickness was 0.02, 0.25, and 0.36 mm initially and 1.32, 1.26, and 1.11 mm finally at 1, 3, and 6 mm apically to implant shoulder level. Mixed model analysis revealed an impact of the preoperative bone status on the facial bone increase. The facial soft tissue thickness was significantly influenced by the gingival biotype.

CONCLUSIONS

The results indicate that an initial severe hard tissue defect allows for significant bone regeneration. The facial soft tissue thickness is primarily influenced by the gingival biotype.