Comparative Analysis of Visual Remark, Digital Digital camera, and Smartphone Pictures for Tooth Shade Choice: An In Vitro Study

Introduction

Esthetics play a pivotal function in up to date prosthodontic apply, notably in anterior restorations, the place optimum coloration matching considerably influences remedy success and affected person satisfaction. Among the assorted determinants of esthetic outcomes, correct tooth shade choice stays one of the difficult and technique-sensitive procedures [1]. An incorrect shade match could compromise the general concord of the restoration, resulting in affected person dissatisfaction regardless of technically sound remedy.

Conventionally, shade choice has been carried out by visible comparability with commercially out there shade guides, such because the VITAPAN Classical system (VITA Zahnfabrik H. Rauter GmbH and Co. KG, Bad Säckingen, Germany). Although broadly practiced, owing to its simplicity and cost-effectiveness, the visible technique is inherently subjective. It is influenced by a number of components, together with the observer’s age, intercourse, expertise, visible acuity, coloration notion, and eye fatigue. Environmental components similar to lighting circumstances, background, metamerism, and surrounding colours additional have an effect on shade dedication. Even with regular coloration imaginative and prescient, human notion varies, thereby lowering reproducibility and reliability [2,3].

To overcome these limitations, digital strategies, similar to using intraoral scanners, digital spectrophotometry, and instrumental and photography-based strategies, have been launched [2–4]. Digital cameras mixed with imaging software program enable goal coloration evaluation by quantifying coloration parameters. They improve communication between clinicians and laboratory technicians and supply documentation for future reference [2,5]. Recently, smartphone cameras geared up with superior imaging sensors and processing capabilities have gained reputation owing to their accessibility, portability, and ease of wi-fi knowledge transmission [6,7]. However, regardless of their widespread use, there’s restricted proof evaluating their accuracy with that of standard visible and digital digicam strategies beneath standardized circumstances.

Therefore, this research aimed to comparatively consider the accuracy of visible, digital digicam, and smartphone pictures strategies for shade choice in esthetic dentistry. The goals had been to evaluate the accuracy of visible shade matching, consider the effectiveness of digital pictures utilizing a digital digicam, study the accuracy of smartphone pictures in shade dedication, and examine the efficiency of all three strategies in attaining correct shade choice.

Materials and strategies

Study design and setting

This in vitro comparative research was carried out on the Department of Prosthodontics, Kothiwal Dental College and Research Centre, Moradabad, Uttar Pradesh from January 2025 to September 2025. This research was designed to match the accuracy of three totally different shade choice strategies: visible shade matching, digital digicam photography-assisted shade matching, and smartphone photography-assisted shade matching beneath standardized circumstances. Ethical approval was obtained from the Institutional Ethical Review Board (KDCRC/IERB/02/2024/34 dated 21.02.2024) previous to the graduation of the research. Written knowledgeable consent was obtained from all observers to take part within the research.

Sample dimension

Sample dimension calculation was carried out utilizing G*Power software program (model 3.9.1, Heinrich Heine University Düsseldorf, Germany), contemplating the first end result because the distinction in accuracy between the visible and digital shade choice strategies, estimated at 28%. With a two-tailed alpha stage of 0.05, 80% statistical energy, and an anticipated absolute distinction of 28% between paired proportions (McNemar’s check), the required minimal pattern dimension was decided to be 100 paired observations. The research included 100 observations per technique obtained from 10 observers who evaluated 10 shade tabs.

Observers’ choice and standardization

A complete of 10 observers participated within the research, which included three professors, 4 postgraduate college students, and three dental laboratory technicians. All observers had been screened for regular coloration imaginative and prescient utilizing Ishihara’s check for coloration deficiency (38-Plate Edition; Kanehara Trading Inc., Tokyo, Japan) [8]. The check was carried out beneath pure daylight circumstances following the producer’s directions. Only observers who made fewer than 5 errors had been included within the research to remove the affect of coloration imaginative and prescient deficiency. Observers had been instructed relating to the research protocol and allowed apply classes previous to knowledge assortment to attenuate procedural bias.

Armamentarium

Two units of VITAPAN Classical shade guides had been used for shade matching procedures. A digital single-lens reflex digicam (Canon EOS 600D, Canon Inc., Tokyo, Japan) was used to seize digital photographic pictures. A smartphone (iPhone 15, Apple Inc., Cupertino, CA, USA) was used for photographic imaging.

Image processing and shade information preparation had been carried out utilizing Adobe Photoshop CS3 Extended Version 10 (Adobe Systems Inc., San Jose, CA, USA) put in on a laptop computer with Windows 10 Pro working system (Microsoft Corporation, Redmond, WA, USA), 8 GB RAM, and 238 GB storage capability.

An 18% grey card (Neewer Technology Co., Shenzhen, China) was used to standardize the publicity and neutral-color stability. A tripod stand was used to mount the DSLR digicam and a selfie stand was used to mount the smartphone. A Nissin Typodont Jaw Set – PRO2001-UL (Nissin Dental Products Inc., Kyoto, Japan) was used to organize the hid digital shade guides. Micropore tape (3M, Maplewood, MN, USA) was used to masks the identification numbers of shade tabs. Ishihara’s assessments for coloration Deficiency, 38-Plate Edition, had been used to evaluate coloration imaginative and prescient.

Sample choice

Ten observers, comprising three professors, 4 postgraduate college students, and three dental technicians, had been chosen based mostly on their medical expertise and willingness to take part. The observers offered knowledgeable consent earlier than their inclusion within the research. Each observer carried out shade matching utilizing three strategies: visible, digital pictures, and smartphone pictures. Each observer matched 10 shade tabs per technique, leading to 100 observations per technique for a complete of 300 observations.

Assessment of coloration imaginative and prescient

All observers had been screened for coloration imaginative and prescient deficiency utilizing Ishihara’s check (38-Plate Edition). The check was carried out beneath pure daylight circumstances to stop coloration distortion. Each plate was introduced at a distance of roughly 70 cm from the observer and was positioned perpendicular to the road of sight. The observers had been instructed to determine the quantity inside 5 seconds for every plate.

The first 17 plates had been used for screening. Observers who made greater than 5 errors had been thought-about color-deficient and excluded from the research. Only those that accurately recognized the screening plates and demonstrated regular coloration notion had been included. The check was carried out individually within the presence of an investigator to keep up confidentiality and stop exterior influences.

Preparation of visible shade guides

Two units of VITAPAN Classical shade guides had been used on this research. Ten shade tabs (A2, A3, A3.5, A4, B2, B3, B4, C2, C3, and D3) had been chosen for this research. One set served because the management shade information, by which the identification numbers had been stored seen. The second set served because the hid shade information, the place identification numbers had been masked utilizing micropore tape and randomly labeled from 1 to 10. The hid shade tabs had been introduced individually in a random sequence, and observers had been instructed to match every hid tab with the corresponding tab within the management shade information (Figure 1).

Preparation of digital and smartphone photographic shade guides

For digital and smartphone shade information preparation, the chosen 10 shade tabs had been positioned over an 18% grey card at a standardized distance of 25 cm beneath northern daylight with a coloration temperature vary of 5000-6500 Okay. For digital pictures, a Canon EOS 600D digicam was mounted on a tripod at a peak of two ft. The standardized digicam settings had been maintained at ISO 200, shutter velocity 1/125 s, aperture F11, focal size 55 mm, handbook publicity mode, and no flash. Images had been captured within the JPEG format with a decision of 5184 × 3456 pixels at 72 dpi.

For smartphone pictures, the iPhone 15 was mounted on a selfie stand at a peak of two ft. Standardized settings included ISO 200, shutter velocity of 1/50 s, aperture of f/1.6, and focal size of 26 mm. Images had been captured within the JPEG format with a decision of 6048 × 8064 pixels beneath related daylight circumstances. The reported decision corresponds to the native picture output of the system. Image orientation didn’t affect shade analysis as a result of the shade tabs had been digitally remoted and standardized throughout picture processing previous to observer evaluation. All pictures had been transferred to a laptop computer and processed utilizing the Adobe Photoshop CS3 Extended software program. The shade tabs had been remoted utilizing a pen device and layered in opposition to a black background to create digital management shade guides.

For hid digital shade-guide preparation, {a photograph} of the typodont with six clearly seen maxillary anterior tooth was captured beneath similar standardized settings. The picture was layered and the related space was chosen utilizing a pen device. Image segmentation was carried out by a single skilled investigator following a predefined enhancing protocol utilizing similar zoom ranges and canvas settings. The pen device was used solely to isolate the shade tab boundaries, and no changes had been made to hue, saturation, brightness, or coloration stability to protect the unique coloration info. Each hid shade tab with a masked identification quantity was digitally positioned in the correct central incisor area. Ten separate Photoshop recordsdata had been created for every hid shade tab, with all of the management shade tabs positioned for comparability (Figure 2).

Procedure for shade matching

Visual shade matching was carried out between 9 a.m. and 10 a.m. beneath pure northern daylight at a room temperature of roughly 26⁰C. All observations and photographic procedures had been carried out throughout the identical time interval (9:00-10:00 a.m.) to attenuate variations in pure daylight. An 18% gray card was used for coloration calibration and similar digicam parameters, positioning, and background circumstances had been maintained for all classes to make sure consistency in illumination circumstances. The management and hid shade guides had been organized on a flat black background. The observers independently matched every hid shade tab to a management shade information. To stop eye fatigue, observers had been instructed to relaxation their eyes by closing them or viewing a grey card intermittently for 15 s. Selected shade tab numbers had been recorded, and proper matches had been counted. For digital and smartphone photographic shade matching, observers in contrast the hid digital shade tab with digital management shade tabs displayed on the display screen utilizing the ready Photoshop recordsdata. The numbers of right and incorrect matches had been recorded. Each observer accomplished 10 observations per technique.

Data assortment and statistical evaluation

A complete of 300 observations had been recorded, comprising 100 observations for every shade-matching technique. Observations had been categorized as right or incorrect based mostly on matching with a predetermined reference shade. Statistical analyses had been carried out utilizing IBM SPSS Statistics, model 26.0 (IBM Corp., Armonk, NY, USA). The accuracy of shade matching for the visible, digital digicam, and smartphone strategies was calculated as proportions with 95% confidence intervals. Differences in associated proportions had been assessed utilizing Cochran’s Q check, adopted by pairwise McNemar’s assessments with Bonferroni adjustment for a number of comparisons. Interobserver settlement for every technique was evaluated utilizing Fleiss’ Kappa statistics, whereas intra-observer settlement between strategies was assessed utilizing Cohen’s kappa coefficient. Statistical significance was set at P < 0.05.

Results

The research included 300 observations obtained from 10 observers (three professors, 4 postgraduate college students, and three laboratory technicians) who evaluated 10 shade tabs utilizing three totally different strategies: standard visible shade choice, digital pictures with a devoted digicam, and digital pictures utilizing a smartphone. The general accuracy of shade matching differed considerably between the three strategies (Table 1). The standard visible technique resulted in 48 (48%) right matches out of the 100 observations. In distinction, the digital digicam technique achieved 77 (77%) right matches, whereas the smartphone technique yielded 76 (76%) right matches. The confidence intervals for each digital strategies had been clearly separated from and better than these for the visible technique, indicating superior efficiency.

Cochran’s Q check confirmed a extremely important general distinction within the proportion of right shade matches among the many three strategies (Q = 94.62, df = 2, p < 0.001) (Table 2).

Subsequent pairwise publish hoc comparisons utilizing McNemar assessments with Bonferroni adjustment (α = 0.016) demonstrated that each digital strategies had been considerably extra correct than the visible technique. The digital digicam technique was related to 5.31 occasions increased odds of an accurate match in comparison with visible evaluation (p = 0.001; 95% CI: 2.78-10.12) (Table 3).

Similarly, the smartphone technique confirmed 4.86 occasions increased odds of right shade choice than did the visible technique (p = 0.001; 95% CI: 2.59-9.12) (Table 4).

No statistically important distinction was noticed between the digital digicam and smartphone strategies (p = 0.70; odds ratio = 1.17; 95% CI: 0.52-2.63) (Table 5).

Accuracy assorted based on the observer’s expertise stage (Table 6). Professors achieved the very best efficiency utilizing the visible technique, adopted by postgraduate college students and laboratory technicians. With the digital digicam, the accuracy improved to 24/30 (80%) amongst professors, 31/40 (77%) amongst postgraduate college students, and 22/30 (73%) amongst laboratory technicians. The smartphone-based evaluation produced related features, reaching 25/30 (83%) for professors, 30/40 (75%) for postgraduate college students, and 22/30 (73%) for laboratory technicians. These outcomes point out that, whereas skilled expertise was related to higher baseline efficiency, digital strategies produced substantial and constant enhancements throughout all observer classes.

Inter-observer settlement, assessed utilizing Fleiss’ kappa, was reasonable for the visible technique (κ = 0.42), reflecting appreciable variability amongst observers. Agreement improved markedly to the substantial vary with each digital methods: κ = 0.68 for the digital digicam and κ = 0.66 for the smartphone technique (Figure 1). This sample means that digital shade choice reduces subjective variations and enhances the consistency amongst observers.

Intra-observer settlement between strategies, evaluated utilizing Cohen’s kappa, was solely truthful when evaluating visible evaluation with both digital approach (visible vs. digital digicam: κ = 0.35; visible vs. smartphone: κ = 0.33) (Figure 4). In distinction, the settlement between the 2 digital strategies was substantial (κ = 0.72), indicating excessive reproducibility when the identical observer used camera-based versus smartphone-based digital seize.

In abstract, each digital shade choice strategies demonstrated considerably increased accuracy, superior inter-observer reliability, and larger between-method consistency than standard visible shade matching. The performances of devoted digital cameras and smartphones had been statistically equal, suggesting that smartphone-based shade choice represents a dependable and accessible different in medical and laboratory settings.

Discussion

The outcomes of the current research demonstrated that each digital strategies considerably outperformed the visible method, with the digital digicam attaining 77% accuracy and smartphone pictures 76%, in contrast with 48% for visible matching. The general distinction among the many strategies was statistically important, highlighting the superior reliability of the technology-assisted methods. Pairwise comparisons confirmed that the digital digicam and smartphone strategies yielded increased right matches than visible evaluation, whereas no important distinction existed between the 2 digital approaches. These findings underscore the potential of digital instruments to mitigate subjectivity in shade choice.

The enhanced accuracy of the digital and smartphone strategies aligns with a number of research that emphasize the restrictions of visible shade matching. Visual dedication is inherently subjective and influenced by observer expertise, lighting circumstances, and metamerism, the place colours seem totally different beneath various gentle sources [9–11]. By distinction, digital pictures permits for standardized picture seize and evaluation utilizing software program similar to Adobe Photoshop, enabling exact coloration comparability in a managed surroundings [11,12]. For occasion, Schropp reported that digital images analyzed utilizing software program had been extra correct than visible strategies due to decreased perceptual variability [11]. Similarly, Jarad et al. discovered that particular person observer efficiency improved considerably with computerized matching [12]. Kelkar et al. famous that digital pictures, particularly with polarizing filters, offers higher outcomes than visible evaluation [13]. The present research’s use of a grey card and daylight (5000-6500 Okay) minimized lighting discrepancies and supported constant outcomes.

Smartphone pictures has emerged as a comparable different to devoted digital cameras, with no important variations in accuracy. This is in keeping with Mohammadi et al., who confirmed excessive validity and reliability of smartphone pictures analyzed utilizing Adobe Photoshop in comparison with spectrophotometers [6]. Alsahafi et al. reported superior accuracy in hue, worth, and chroma utilizing smartphones in comparison with visible and instrumental strategies [14]. Tam and Lee demonstrated possible shade classification utilizing smartphone cameras and machine studying, attaining excessive accuracy [15]. Rondon et al. discovered photographic evaluation to be extra exact than visible matching beneath standardized protocols [16]. The accessibility of smartphones makes them a cheap device for medical use, as famous by Abraham et al. for grayscale worth dedication [17]. In the current research, the slight fringe of digital cameras could stem from a better decision (5184 × 3456 pixels vs. 6048 × 8064, however optimized settings), but the ubiquity of smartphones presents sensible benefits.

Observer expertise influenced baseline efficiency, with professors attaining increased visible accuracy than college students and technicians, corroborating Paul et al.’s findings on the consistency of skilled observers [18]. However, digital strategies have decreased this hole, bettering accuracy throughout all teams, as seen in Alshiddi et al.’s comparability of skilled and untrained members [19]. Udiljak et al. highlighted technicians’ superior precision owing to their routine fabrication duties [20]. The inclusion of various observers on this research displays real-world variability, however digital instruments democratize accuracy and reduce experience-related bias.

Clinically, these findings indicate that integrating digital and smartphone pictures into prosthodontic workflows can improve shade communication between clinicians and laboratories, thereby lowering remakes and affected person dissatisfaction. Smartphone strategies, being transportable and low-cost, are notably helpful in resource-limited settings or teledentistry. They facilitate goal documentation of remedy planning and authorized information. Adopting standardized protocols similar to zero-contact distance, perpendicular angulation, and daylight circumstances can optimize the outcomes. This might enhance esthetic outcomes in mounted prostheses, veneers, and crowns, the place shade mismatch impacts affected person satisfaction.

Limitations embody the in vitro design and use of synthetic setups that don’t replicate intraoral circumstances similar to moisture, angulation, or adjoining tooth affect. The VITAPAN Classical information has restricted shades, and the VITA 3D-Master presents extra choices. No time restrict was imposed, doubtlessly overlooking eye fatigue. Experience was categorized however not quantified, and the small pattern (300 observations) restricted generalizability. Another limitation of the research is that the photographic strategies didn’t particularly account for the precept of metamerism, the place colours could seem totally different beneath various lighting circumstances. Additionally, polarizing filters weren’t used throughout picture seize to scale back floor reflections or glare, which can have launched minor variations in coloration notion. Future research ought to incorporate in vivo eventualities, bigger cohorts, superior software program based mostly on synthetic intelligence, and a number of shade guides beneath assorted lighting.

Conclusions

Within the constraints of this in vitro investigation, each digital digicam pictures and smartphone-based pictures proved to be markedly superior to standard visible shade choice, when it comes to accuracy and consistency. Digital approaches demonstrated considerably increased reliability and decreased inter-observer variability in comparison with the subjective nature of visible matching. Moreover, the 2 digital strategies exhibited equal efficiency, with substantial settlement between them, and improved reproducibility throughout observers with various expertise ranges. These outcomes spotlight the worth of goal technology-assisted methods in overcoming the inherent limitations of human visible notion throughout shade dedication. Adopting standardized digital pictures protocols in medical prosthodontic apply has the potential to reinforce shade communication with dental laboratories, reduce remakes, and enhance general esthetic predictability and affected person satisfaction. Future in vivo research beneath various medical circumstances are advisable to substantiate these findings additional and facilitate broader implementation.