Soft tissue metric parameters, methods and aesthetic indices in implant dentistry: A critical review

Evaluation of the Pink Esthetic Score for Single Implants in the Esthetic Zone Using Intraoral Scanning Data: A Proof-of-Concept Study

OBJECTIVES

To evaluate the feasibility of esthetic assessments based on intraoral scanning data using pink and white esthetic scores (PES/WES).

MATERIALS AND METHODS

Thirty samples with both intraoral photographs and scanning data were collected and rated by two observers with excellent consistency independently. PES includes seven variables, and WES includes five. The maximum scores were 14 and 10, respectively.

RESULTS

The mean PES/WES was 10.60 ± 1.69 and 8.50 ± 1.28 for photographs and 10.97 ± 1.69 and 8.40 ± 1.25 for scanning data. No significant difference was observed between the two sample types. The alveolar process variable had significantly higher scores, while the soft-tissue color variable had significantly lower scores based on intraoral photographs compared to scanning.

CONCLUSIONS

Intraoral scanning could be a method for the esthetic evaluation of single implant-supported restorations using PES/WES. The use of three-dimensional imaging enables the precise assessment of esthetic outcomes, paving the way for improvements in the digital workflow of implant dentistry. However, the limitations of color and texture reproducibility should be noted.

CLINICAL SIGNIFICANCE

Intraoral scanning data can be used for esthetic evaluation, and reliable results could be achieved with the application of scanning.

Prediction of pink esthetic score using deep learning: A proof of concept

OBJECTIVES

This study aimed to develop a deep learning (DL) model for the predictive esthetic evaluation of single-implant treatments in the esthetic zone.

METHODS

A total of 226 samples, each comprising three intraoral photographs and 12 clinical features, were collected for proof of concept. Labels were determined by a prosthodontic specialist using the pink esthetic score (PES). A DL model was developed to predict PES based on input images and clinical data. The performance was assessed and compared with that of two other models.

RESULTS

The DL model achieved an average mean absolute error (MAE) of 1.3597, average root mean squared error (MSE) of 1.8324, a Pearson correlation of 0.6326, and accuracies of 65.93 % and 85.84 % for differences between predicted and ground truth values no larger than 1 and 2, respectively. An ablation study demonstrated that incorporating all input features yielded the best performance, with the proposed model outperforming comparison models.

CONCLUSIONS

DL demonstrates potential for providing acceptable preoperative PES predictions for single implant-supported prostheses in the esthetic zone. Ongoing efforts to collect additional samples and clinical features aim to further enhance the model's performance.

CLINICAL SIGNIFICANCE

The DL model supports dentists in predicting esthetic outcomes and making informed treatment decisions before implant placement. It offers a valuable reference for inexperienced and general dentists to identify esthetic risk factors, thereby improving implant treatment outcomes.

Immediate Implant Placement in the Esthetic Zone: A Multi-Variate Analysis of Influencing Factors

OBJECTIVES

To evaluate the dimensional reduction of the peri-implant hard tissues and esthetic outcome after immediate implant placement (IIP) in the esthetic zone.

MATERIAL AND METHODS

Patients who received IIP with bone grafts in the esthetic zone, with either immediate or delayed restoration, were included in this retrospective cohort study. The implants were categorized into three groups based on the labial bone thickness (LBT) before implantation: Group 1 (≤ 0.5 mm), Group 2 (0.5-1 mm), Group 3 (≥ 1 mm). The horizontal bone loss (HBL) at 0, 3, 5 mm apical to implant shoulder, peri-implant marginal bone loss (MBL), and Pink Esthetic Score (PES) were used to evaluate the hard and soft tissue after IIP.

RESULTS

A total of 87 implants in 74 patients met the inclusion criteria. Compared to group 3, there was significant severe bone loss in the HBL-0 mm in groups 1 (p = 0.017); and the implant located in the central incisor position and female may led to increased bone resorption (p = 0.021, p = 0.061, respectively). For HBL-3 mm and HBL-5 mm, the non-immediate restoration may reduce bone resorption (p = 0.013, p = 0.022, respectively). The MBL during short-term follow-up and PES score showed no significant difference among three groups.

CONCLUSIONS

Despite limitations, our study found that LBT < 0.5 mm significantly affected horizontal bone loss. Meanwhile, immediate restoration, implant position of central incisors and female may also be considered as risk factors for HBL. However, the difference in the labial bone did not significantly affect MBL, or peri-implant soft tissue outcomes.

TRIAL REGISTRATION

This study was registered in a clinical trial registry (www.chictr.org.cn, No: ChiCTR2400087990).

Clinical, radiographic, and aesthetic outcomes at two narrow-diameter implants to replace congenital missing maxillary lateral incisors: A 3-year prospective, clinical study

INTRODUCTION

To present the 3-year clinical, radiographic, and aesthetic outcomes in patients with congenitally missing lateral incisors rehabilitated with two narrow-diameter implants (NDIs).

METHODS

The original population consisted of 100 patients rehabilitated with a cement-retained bi-layered zirconia single-unit crown supported by either a Ø2.9 mm (Test) or a Ø3.3 mm (Control) NDI (n = 50). At the 1- and 3-year follow-up (T2, T3), implant survival rate, crestal bone level (CBL) changes, biological, and technical complications were recorded, while the assessment of the aesthetic outcomes was performed using the Copenhagen Index Score.

RESULTS

Seventy-four patients Ø2.9 mm (n = 39) or Ø3.3 mm (n = 35) reached T3, as 24 patients were lost to follow-up and 1 implant (Ø3.3 mm) was removed. Throughout the observation period, minimal CBL changes (i.e., <1 mm) were detected between groups. Despite the positive aesthetic scores recorded (i.e., 1-2), at T3 20% of patients rehabilitated with a Ø3.3 mm versus 2.6% of patients Ø2.9 mm displayed an alveolar process deficiency (Score 3). No additional technical and/or mechanical complications were recorded between T2 and T3. Tooth vitality was maintained in all neighboring teeth. Peri-implant probing depths and plaque scores remained low in both groups (p > 0.05).

CONCLUSION

The use of 2.9 or 3.3 diameter implants showed comparable favorable mid-term results in terms of survival rate, CBL, and aesthetic outcomes. Hence, clinicians should rely on the use of such NDIs when replacing maxillary lateral incisors.

The use of digital technologies in peri-implant soft tissue augmentation - A narrative review on planning, measurements, monitoring and aesthetics

OBJECTIVE

To identify the different uses and modalities of digital technologies to diagnose, plan and monitor peri-implant soft tissue conditions and aesthetics.

METHODS

A comprehensive narrative review of pertinent literature was conducted, critically appraising key digital technologies that may assist peri-implant soft tissue augmentation and assessment. An electronic search on four databases including studies published prior to 1st July 2023 was performed and supplemented by a manual search.

RESULTS

Predominantly, tools such as cone beam computed tomography (CBCT), intraoral scanning (iOS), intraoral ultrasonography and digital spectrophotometry were commonly to assess and monitor peri-implant soft tissues. The main clinical and research applications included: (i) initial assessment of mucosal thickness, supra-crestal tissue height and keratinized mucosa width, (ii) evaluation of peri-implant soft tissue health and inflammation, (iii) monitoring profilometric changes and midfacial mucosal margin stability over time and (iv) aesthetic evaluation through colour assessment. While evidence for some digital tools may be limited, the integration of digital technologies into peri-implant soft tissue management holds great promise. These technologies offer improved precision, comfort and speed in assessment, benefiting both patients and clinicians.

CONCLUSION

As digital technologies progress, their full potential in peri-implant soft tissue augmentation and their value will become more evident with ongoing research. Embracing these innovations and their potential benefits is recommended to ensure that during progress in implant dentistry, patient care is not hindered.

A prospective case series on the efficacy of a cross-linked collagen matrix to increase buccal soft tissue thickness at large edentulous gaps: One-year results

OBJECTIVE

The objective of this study is to assess profilometric changes following soft tissue augmentation with a cross-linked porcine-derived collagen matrix (CMX) at large edentulous gaps of at least two units.

MATERIALS AND METHODS

Systemically healthy, nonsmoking patients with a large edentulous gap of at least two units demonstrating a horizontal soft tissue defect, were enrolled in a prospective case series. Soft tissue augmentation was performed in a one-stage approach with a 6 mm thick CMX at the time of implant placement. The primary outcome was the change in buccal soft tissue profile (BSP) at a mesial, central, and distal area of interest (AOI) up to 1 year when compared to the preoperative situation based on superimposed digital surface models. Secondary outcomes included the horizontal dimension of the soft tissue defect, complications, and marginal bone loss (MBL).

RESULTS

Fifteen patients (eight females; mean age 58.73 years) were enrolled and 13 could be re-assessed at 1-year follow-up. The mean linear increase in BSP at 1 year was 0.66 mm (98.3% CI: 0.37-0.94), 0.80 mm (98.3% CI: 0.39-1.22), and 0.69 mm (98.3% CI: 0.32-1.06) at the mesial, central, and distal AOI, respectively. Substantial shrinkage of about 75% was observed in all areas between augmentation and 1-year follow-up. Even though 11 of 13 sites were fully augmented immediately postoperative, a soft tissue defect recurred in all sites at 1-year follow-up with a mean deficit of 2.30 mm. Altogether, 25% of the original soft tissue defect was eliminated by soft tissue augmentation. CMX was safe since no postoperative complications occurred and MBL was limited (0.70 mm).

CONCLUSION

CMX is efficacious for horizontal soft tissue augmentation at large edentulous gaps. However, considerable graft resorption may be expected, and the clinical relevance of the augmentation may be questionable since all patients demonstrated a recurring and considerable soft tissue defect 1 year after surgery.

Annual review of selected scientific literature: A report of the Committee on Scientific Investigation of the American Academy of Restorative Dentistry

The Scientific Investigation Committee of the American Academy of Restorative Dentistry offers this review of the 2021 dental literature in restorative dentistry to inform busy dentists regarding noteworthy scientific and clinical progress over the past year. Each member of the committee brings discipline-specific expertise to coverage of this broad topical area. Specific subject areas addressed, in order of the appearance in this report, include COVID-19 and the dental profession (new); prosthodontics; periodontics, alveolar bone, and peri-implant tissues; implant dentistry; dental materials and therapeutics; occlusion and temporomandibular disorders; sleep-related breathing disorders; oral medicine and oral and maxillofacial surgery; and dental caries and cariology. The authors focused their efforts on reporting information likely to influence daily dental treatment decisions with an emphasis on future trends in dentistry. With the tremendous volume of dentistry and related literature being published daily, this review cannot possibly be comprehensive. Rather, its purpose is to update interested readers and provide important resource material for those interested in pursuing greater details on their own. It remains our intent to assist colleagues in negotiating the extensive volume of important information being published annually. It is our hope that readers find this work useful in successfully managing the patients and dental problems they encounter.

A multi-centre randomized controlled trial comparing connective tissue graft with collagen matrix to increase soft tissue thickness at the buccal aspect of single implants: 1-year results

AIM

To compare connective tissue graft (CTG) with collagen matrix (CMX) in terms of increase in buccal soft tissue profile (BSP) at 1 year when applied at single implant sites.

MATERIALS AND METHODS

Patients with a single tooth gap in the anterior maxilla and horizontal mucosa defect were enrolled in a multi-centre RCT. All sites had a bucco-palatal bone dimension of at least 6 mm, received a single implant and an immediate implant restoration using a full digital workflow. Sites were randomly allocated to the control (CTG) or test group (CMX) to increase buccal soft tissue thickness. The primary outcome was the increase in BSP at 1 year when compared to the pre-operative situation based on superimposed digital surface models. The changes in BSP over time were registered at a buccal area of interest reaching from 0.5 mm below the soft tissue margin to 4 mm more apical. Secondary outcomes included patient-reported, clinical and aesthetic outcomes.

RESULTS

Thirty patients were included per group (control: 50% females, mean age 50.1; test: 53% females, mean age 48.2). The increase in BSP at 1 year was 0.98 mm (98.3% CI: 0.75 - 1.20) for CTG and 0.57 mm (98.3% CI: 0.34 - 0.79) for CMX. The mean difference of 0.41 mm (98.3% CI: 0.12 - 0.69) in favour of CTG was significant (p < 0.001). Based on an arbitrarily chosen threshold for success of 0.75 mm increase in BSP, 89.7% of the patients in the control group and 10% of the patients in the test group were successfully treated (OR = 77.90; 95% CI 13.52 - 448.80; p < 0.001). Sites treated with CMX demonstrated 0.89 mm (98.3% CI: 0.49 - 1.30) more shrinkage between postop and 1 year than sites treated with CTG. In addition, CMX resulted in significantly more marginal bone loss (0.39 mm; 95% CI 0.05- 0.74; p = 0.026) than CTG. There were no significant differences between the groups in terms of patients' aesthetic satisfaction (p = 0.938), probing depth (p = 0.917), plaque (p = 0.354), bleeding on probing (p = 0.783), midfacial recession (p = 0.915), Pink Esthetic Score (p = 0.121) and Mucosal Scarring Index (p = 0.965).

CONCLUSION

CTG remains the gold standard to increase soft tissue thickness at implant sites. Clinicians need to outweigh the benefits of CMX against considerable resorption of the graft.

Possibilities and challenges in digital personal identification using teledentistry based on integration of telecommunication and dental information: a narrative review

Personal identification using dental evidence is decisive in the case of unidentified bodies because dental features, including decayed, missing and filled teeth, are unique to every individual. This review explored the possibilities and problems associated with personal identification through digital methods by the integration of telecommunications and dentistry, also known as teledentistry. Establishment of a global, objective personal identification method using dental evidence through teledentistry is desirable. However, the review reports that there are various problems that need to be resolved first, in aspects such as changes in dentition over time, technology, individual privacy and ethics. It is suggested that solving such problems and constructing a worldwide dental database for personal identification from dental images, using teledentistry, as part of social services, is a new challenge for researchers in forensic odontology and dentistry.

Evaluation of gingival recessions with conventional versus digital methods

OBJECTIVES

The present study aimed to compare the conventional clinical and digital methods evaluating differences in gingival recession (ΔREC) in patients with advanced periodontitis treated with the non-surgical treatment protocol.

METHODS

Agreement between the methods was evaluated on a sample of ten patients with periodontitis (stage III/IV, grade B/C) with acquired clinical measurements and digital models from baseline (T0) and 12-months after non-surgical treatment of periodontitis (T1). The evaluation was performed on maxillary teeth from right to left second premolar resulting in overall 99 teeth. Clinical evaluation was performed by subtracting the distance measurements between gingival margin and cemento-enamel junction, obtained at T0 and T1 by a calibrated examiner (intra-examiner agreement >90%). The digital evaluation was performed directly by measuring the distance between the gingival margins on superimposed T0 and T1 digital models. Using Bland-Altman and statistical analysis, all six measurements sites around each included tooth (n=594) acquired with both methods were compared.

RESULTS

Median ΔREC (5th and 95th percentile) acquired with a conventional clinical and digital method was 0.0mm (-2.0 - 1.0) and -0.4mm (-1.6 - 0.8), respectively (p<0.0001). The complete agreement between rounded digital and clinical ΔREC values was only 38%, revealing high disagreement also confirmed by Bland-Altman analysis with 95% limits of agreement ranging from -2.6 to 1.8mm. Absolute differences between the methods higher than 0.5 and 1 mm, was found in 61% and 38% of measurement sites, respectively.

CONCLUSIONS

The conventional clinical method for ΔREC evaluation exhibits lower sensitivity and accuracy than the digital method.

CLINICAL SIGNIFICANCE

The quality of both clinical and research data in periodontology and implantology can be considerably improved by the digital method while still preserving the compatibility with the conventional clinical method.

Free-Hand versus Surgical Guide Implant Placement

One of the most key areas of dentistry is dental implant surgery. The use of digital equipment and software in dentistry has developed considerably in recent years compared to other fields of medicine. Since examining the advantages and disadvantages of each approach, along with case studies, can help physicians make informed decisions, this review study aims to raise the awareness of dentists to make easier decisions about using guided or free-hand surgery. When planning for a dental implant, one of the most challenging questions that doctors face is which method to use (guided surgery or free-hand). Choosing the right method, such as other clinical considerations, will depend on the individual circumstances of each patient and the preference of the treating physician. Free-hand surgery is a cost-effective method in which the flap is reflected, and, according to the doctor's diagnostic information, an implant is placed, which in many cases is a useful method. Guided surgery has the highest level of accuracy and control, in which osteotomy is designed and printed through a digital surgery guide, and depending on the complexity of the case and the patient's anatomy, it has a higher level of value than free surgery. The surgical guide helps the surgeon make the implant surgery more accurate, safer, simpler, at a lower cost, and in less time. In fact, there are patterns that convey information about the position of the tooth to the dentist before the implant is placed.

Esthetic evaluation of single implant-supported prostheses: Comparative analysis of the reliability of the esthetic indices

OBJECTIVES

To carry out a detailed analysis of four indices proposed for the esthetic evaluation of implant-supported single crowns in the anterior maxillary sector.

MATERIAL AND METHODS

Four esthetic indices were selected: the Pink and white esthetic score, the Copenhagen Index Score, the peri-implant and crown index (PICI), and the implant restoration esthetic index (IREI). The examiners were 15 expert subjects and 30 nonexpert ones. The intraclass correlation coefficient was used to assess reproducibility. The validity and the correlation of the esthetic indices results with the perception of nonexpert subjects were evaluated using the Pearson's correlation.

RESULTS

For inter- and intra-observer reproducibility, all the esthetic indices had an intraclass correlation coefficient value>0.8. As for validity, the highest correlation values were found for the PICI and for the IREI. The values of correlation with the perception of nonexpert subjects did not exceed 0.3 for all esthetic indices.

CONCLUSIONS

All esthetic indices evaluated presented good intra- and inter-rater reproducibility. Validity was considered satisfactory only for the PICI and the IREI. The correlation with the perception of nonexpert subjects showed a weak correlation with all the indices considered.

CLINICAL SIGNIFICANCE

An approved esthetic indice with proven reproducibility and validity could provide a better objective overview of one's own esthetic results in the daily practice. It could also help to record the results over time to analyze the stability of the treatment procedure. The esthetic results of the different surgical and prosthetic protocols can also be compared, which facilitates the analysis of the indications relevance and clinical effects. However, low reproducibility according to the specialty and the practitioner's level of expertise was observed. A heterogeneity of results was also noted when compared with those of nonexpert subjects.

A multi-centre randomized controlled trial comparing connective tissue graft with collagen matrix to increase soft tissue thickness at the buccal aspect of single implants: 3-month results

AIM

To compare connective tissue graft (CTG) with collagen matrix (CMX) in terms of changes over time in buccal soft tissue profile (BSP) when applied at single implant sites.

MATERIALS AND METHODS

Patients with a single tooth gap in the anterior maxilla and horizontal mucosa defect were enrolled in a multi-centre randomized controlled trial. All sites had a bucco-palatal bone dimension of at least 6 mm and received a single implant and immediate implant restoration using a full digital workflow. Sites were randomly allocated to the control (CTG) or test group (CMX: Geistlich Fibro-Gide®, Geistlich Pharma AG, Wolhusen, Switzerland) to increase buccal soft tissue thickness. Primary outcome was increase in BSP at T1 (immediately after operation) and T2 (3 months) based on superimposed digital surface models. Secondary parameters included patient-reported clinical and aesthetic outcomes.

RESULTS

Thirty patients were included per group (control: 50% females, mean age 50; test: 53% females, mean age 48). Even though surgeons applied thicker grafts when using CMX, sites treated with CMX demonstrated 0.78 mm (95% CI 0.41-1.14) more shrinkage between T1 and T2 than sites treated with CTG. The final increase in BSP was 1.15 mm (95% CI 0.88-1.43) for CTG and 0.85 mm (95% CI 0.58-1.13) for CMX. The mean difference of 0.30 mm (95% CI -0.01 to 0.61) at T2 in favour of CTG was of borderline significance (p = .054). There were no significant differences between the groups in terms of post-operative bleeding (p = .344), pain (p = .331), number of analgesics taken (p = .504), oedema (p = .227), and pink aesthetic score (p = .655). VAS for post-operative haematoma was 6.56 (95% CI 0.54-12.59) lower for CMX, and surgery time could be reduced by 9.03 min (95% CI 7.04-11.03) when applying CMX. However, CMX resulted in significantly more marginal bone loss (0.38 mm; 95% CI 0.15-0.60), deeper pockets (0.30 mm; 95% CI 0.06-0.54), and more mid-facial recession (0.75 mm; 95% CI 0.39-1.12) than CTG.

CONCLUSIONS

CTG remains the gold standard for increasing soft tissue thickness at the buccal aspect of implants.