Photogrammetry technology in full arch implant-supported rehabilitations: a systematic review

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Universidade de Lisboa Faculdade de Medicina Dentária

Photogrammetry technology in full arch

implant-supported rehabilitations: a systematic review

Daniel Filipe da Conceição Moniz Barreto

Orientada pelo Prof. Doutor Duarte Marques e coorientada pelo Prof. Doutor António Mata

Dissertação

Mestrado Integrado em Medicina Dentária

2022

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Universidade de Lisboa Faculdade de Medicina Dentária

Photogrammetry technology in full arch

implant-supported rehabilitations: a systematic review

Daniel Filipe da Conceição Moniz Barreto

Orientada pelo Prof. Doutor Duarte Marques e coorientada pelo Prof. Doutor António Mata

Dissertação

Mestrado Integrado em Medicina Dentária

2022

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Dissertação formatada de acordo com as normas de publicação da revista International Journal of Oral Implantology

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... se antes de cada ato nosso, nos puséssemos a prever todas as consequências dele, a pensar nelas a sério, primeiro as imediatas, depois as prováveis, depois as possíveis, depois as imagináveis, não chegaríamos sequer a mover-nos de onde o primeiro pensamento nos tivesse feito parar.

- José Saramago

Tudo o que é bom, dura o tempo necessário para ser inesquecível.

- Fernando Pessoa

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ACKNOWLEDGMENTS

Professor Duarte Marques, DDS, Ph.D., for the frontality, patience, and critical sense, which made me embark on this challenge with the certainty that its path would be hard, but it would be worth it.

Professor António Mata, DDS, Ph.D., for the serenity shown in every moment, and for the literary advice that led me to read Parallel Worlds, by Michio Kaku.

Carlota Mendonça, for showing me and all my colleagues that is possible to manage a busy and active social life with top-quality academic results and clinical responsibilities. Also, for being available to discuss my most basic doubts.

Sofia, for your merciless insistence on making sure the first page of this thesis would start to be written, and the victory over procrastination would become a palpable reality instead of mere speculation. For having been a pillar throughout my academic and personal journeys.

The path was difficult and troubled, but it became more pleasant with you right by my side.

Sofia Morais, for spreading anything but positivity, smiles, and good energy. You’re a case study by itself and I’m proud of everything you’ve done so far. The duo 14 will never be forgotten.

Marta Borges, for sharing one of the best and more unique experiences of my life and being a great flatmate, travel partner, and after all, a good friend. Living abroad was an experience I’ll never forget, and you will be in almost every memory I’ll cherish from that city.

Zagreb was not prepared for us.

GIBBO for teaching me how to do research, and surrounding me with materials, people, and innovative technology.

Tuna Médica de Lisboa for all the songs played, music festivals and competitions, vacations together, and for showing me that a doctor that only knows about his field of work doesn’t even know anything about Dental Medicine.

Mom, for letting me exist, in the first place, and for not conditioning in any way that same existence. If I didn’t feel like missing anything in life, I owe it to you. I hope one day I can give you everything in return and that these pages can represent the beginning of that retribution.

And last, but not least, to all my peers, professors, and assistants that made me learn, improve my skills, and provided a friendly shoulder to cry over when I needed it, and especially to Leonor Castêdo, Jessica Coelho, João Grilo, Alexandra Irimia and Carlota Henriques for these past few months. I’ll carry one tiny piece of every single one of you, everywhere and always, and hope that I left a little mark on your lives too.

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ABSTRACT

Objective: Perform a Systematic review to compare the accuracy of three methods of impressions on full arch implant-supported rehabilitations: photogrammetry (PG) against conventional (CNV) and intraoral digital scanning (IOS) techniques.

Material and Methods: Electronic and manual searches were undertaken in four major databases (ScienceDirect, PubMed, Cochrane, and LILACS), until 8th August 2022. A manual search was made to enlarge the number of articles, complemented by a grey literature search (Google Scholar), and study quality assessed through established methods.

Results: Twenty-one articles were retrieved from the search, 10 in vitro and 11 in vivo, based on the selection criteria and subjected to critical appraisal. With only 1 RCT included, a meta-analysis was not performed. Regarding 3D deviation, significant differences in precision, trueness, and overall accuracy in favor of PG were reported by one RCT and in vitro studies.

Position and number of implants, and inter-implant angulations did not affect the accuracy of PG, both in clinical and in vitro settings. As reported by one RCT pilot, marginal bone loss was not significantly different across all methods, and PG was reportedly more time-effective, compared to CNV.

Conclusions: Most studies reported that PG showed significantly better accuracy in full arch implant impressions, compared to IOS and CNV, and within the clinical acceptance threshold. More clinical studies are needed to develop the technology and validate these claims, preferably with much larger samples, and more standardized protocols. Soft tissue scanning integration in PG would drastically reduce working time and number of procedure steps.

Clinical significance: Photogrammetry technology seems to reproduce and transfer implant positions with high accuracy levels, thus improving the overall quality of full arch implant-supported rehabilitations, within a fully digital workflow, when complemented with an intraoral scanner to register soft tissue information.

Keywords: Dental Implants [D015921], Dental Impression Technique [D003761], Photogrammetry [D010780], Dimensional Measurement Accuracy [D061827].

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RESUMO

Em reabilitações totais implanto-suportadas, a ausência de passividade entre os implantes e a estrutura reabilitadora tem sido associada a uma taxa de complicações considerável. Entre outros, a reprodução precisa da localização tridimensional (3D) dos implantes ou pilares apresenta-se como o fator mais crítico. Embora a precisão dos scanners intraorais (IOS) seja reconhecida para coroas unitárias e reabilitações parciais até três elementos, as impressões em arcadas totais implanto-suportadas realizadas com estes sistemas não são suficientemente precisas para aplicação clínica. Segundo a literatura, as técnicas convencionais apresentam melhor desempenho.

Em 1999, Jemt et al. referiram que a fotogrametria (PG) poderia registar, com sucesso, as posições das réplicas dos implantes na impressão de uma mandíbula edêntula, e que a sua precisão era comparável à da técnica convencional (CNV). A PG utiliza vários pontos de referência em fotografias para fazer medições precisas, transformando esses dados visuais numa lista de coordenadas. Atualmente, vários sistemas fotogramétricos foram projetados e fabricados comercialmente, como a PIC Camera e a ICam4D, que combinam técnicas de fotogrametria com luz estruturada, por via de um sistema integrado de câmaras, projetores e pequenos acessórios que são encaixados na cabeça dos implantes.

De acordo com a ISO 5725, exatidão é composta por veracidade e precisão. A primeira expressa o quão próximas as medições obtidas se encontram do valor real, enquanto a segunda corresponde ao grau de proximidade entre as medições obtidas em digitalizações consecutivas.

Assim, o objetivo da presente revisão sistemática foi comparar a exatidão (precisão e/ou veracidade) de três métodos de impressão em reabilitações totais fixas implanto-suportadas:

fotogrametria, scanners intraorais, e técnica convencional. A sua elaboração seguiu as guidelines PRISMA 2020, tendo sido registada na plataforma PROSPERO com o número CRD42022351669. A questão-problema foi elaborada usando o formato PICO: Em reabilitações totais implanto-suportadas, quais são as diferenças de exatidão entre fotogrametria, técnica convencional e scanners intraorais? Além disso, o resultado clínico, a satisfação do paciente e do médico-dentista e a duração do procedimento foram considerados outcomes secundários. A pesquisa bibliográfica foi realizada em quatro das principais bases de dados, selecionando artigos publicados nos últimos dez anos, tendo sido alargada por uma pesquisa manual e complementada com uma pesquisa na literatura cinzenta de acordo com critérios previamente estabelecidos.

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Os principais critérios de inclusão foram os seguintes: (P) pacientes edêntulos com reabilitações totais fixas implanto-suportadas como plano de tratamento, ou pacientes reabilitados com este tipo de restauração; (I) estudos cuja intervenção sejam impressões da posição dos implantes/análogos ou seus pilares, com sistema fotogramétrico; (C) estudos que comparem a técnica de fotogrametria com métodos convencionais, ou impressões com scanner intraoral; e (O) estudos que considerem como desfechos a exatidão (precisão e/ou veracidade) expressa como desvio 3D geral (diferença média; média ± desvio-padrão, DP; ou root mean square, RMS), desvios angulares ou lineares, tempo de trabalho (min.), satisfação do médico- dentista e/ou do paciente (escala visual analógica, EVA), ou avaliação clínica/duração de follow-up. Quanto aos principais critérios de exclusão: estudos com zero implantes colocados (critério a); apenas reabilitações parciais ou coroas unitárias (critério b), ou intervenção/tecnologia utilizada errada (critério c).

Os títulos e resumos de todos os artigos identificados através de busca eletrónica foram lidos de forma independente por dois autores (DB e DM). Para as avaliações de qualidade e risco de viés (RoB), diferentes ferramentas de avaliação foram utilizadas. Quaisquer discordâncias foram resolvidas através de discussão entre os avaliadores. A extração de dados foi realizada e transcrita para uma folha de cálculo online, a qual foi utilizada para gerir todos os dados mencionados. Os autores dos respetivos artigos foram contactados, em caso de falta de alguns destes dados.

Em relação ao risco de viés, os autores consideraram que todos os estudos in vitro apresentaram algumas preocupações, com a exceção de um, tendo sido classificado como baixo risco de viés. Na maioria dos casos, os principais problemas dessas publicações estiveram relacionados com a ausência de cálculo do tamanho da amostra (critério A) e/ou a sequência de alocação, aleatorização e ocultação (critério F). Nos estudos in vivo, todos os casos clínicos, bem como a série de casos clínicos, foram considerados de qualidade “preocupante”. O ensaio clínico aleatorizado piloto incluído apresentou “baixo risco” de viés. No que diz respeito aos ensaios clínicos não-aleatorizados, um deles foi considerado como tendo “baixo risco” de viés, enquanto o outro apresentou um “sério risco” de viés. Por fim, o estudo de teste diagnóstico incluído foi considerado como tendo um 'baixo risco' de viés.

Todos os estudos, à exceção de dois in vitro, relataram diferenças significativas de exatidão entre PG e as restantes técnicas, quando a avaliação foi realizada a nível tridimensional. Em relação aos desvios lineares e angulares para diferentes distâncias entre implantes (IID), os resultados diferiram, com um artigo demonstrando diferenças significativas nos desvios lineares em dois intervalos específicos de IID, enquanto outro concluiu que a

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precisão não foi afetada pela IID. Um ensaio clínico não-aleatorizado publicado em 2022, reunindo 120 implantes divididos em dois grupos (PG: 17 e IOS: 9 participantes) avaliou o impacto que a posição e o número de implantes teria na exatidão. Os autores não encontraram uma correlação significativa entre a posição e número dos implantes com a precisão da impressão para a técnica PG, enquanto no grupo IOS foi encontrada uma correlação positiva fraca. Além disso, considerando 150 µm como o limite estabelecido para esta revisão para resultados clínicos aceitáveis, a exatidão da PG relatada pelos artigos incluídos está dentro desse intervalo, uma vez que o seu erro variou entre 20 e 77,6 µm.

Apenas um ensaio clínico aleatorizado piloto avaliou o tempo de trabalho necessário para a realização das impressões. Quando comparado com a CNV, a técnica PG foi significativamente (p<0,001) inferior. Além disso, o mesmo artigo relatou resultados referentes à satisfação, tanto dos participantes como dos médicos-dentistas. Os valores médios de satisfação ± desvio padrão foram superiores em impressões com PG, quando comparados com o método convencional, revelando-se estatisticamente significativos (p=0,028 e p=0,030, respetivamente).

Através do exame clínico, a avaliação do sucesso do tratamento baseou-se principalmente na verificação de um ajuste passivo das restaurações, imagens radiográficas, conforto do paciente e ausência de complicações no follow-up. Todos relataram que as estruturas baseadas na técnica PG eram comparáveis ao método de referência na sua passividade, que foi alcançada em todos os casos clínicos. Além disso, apenas um RCT piloto avaliou clinicamente a perda marginal óssea em 18 pacientes reabilitados com reabilitações fixas implanto-suportadas sem regeneração óssea, comparando as técnicas de PG e CNV.

Ambos os grupos obtiveram resultados dentro do limite aceite pela literatura e sem diferenças estatísticas entre si.

Os sistemas fotogramétricos são, neste momento, incapazes de reproduzir os tecidos moles de forma precisa. Assim, uma segunda impressão destes tecidos com scanner intraoral ou por métodos convencionais é necessária para complementar a informação da posição dos implantes. Desta forma, alguns dos erros do IOS poderão ser adicionados à impressão, reduzindo a precisão geral do arquivo. No entanto, todos os estudos incluídos descreveram a realização de uma segunda impressão, seja com métodos convencionais ou com diferentes sistemas IOS, ainda que nenhum dos artigos in vitro tenha simulado as condições intraorais, especialmente com CNV, onde a contração do material desempenha um papel importante na adição de erros. Embora as técnicas de DSLR tenham sido usadas em estudos in vitro, a sua aplicação a nível clínico é difícil, pois é necessária uma quantidade elevada de padronização

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para garantir níveis adequados de precisão. No entanto, mesmo com a necessidade de uma segunda impressão para registar os tecidos moles, as técnicas fotogramétricas oferecem tempos de trabalho mais curtos.

Apesar da sua alta exatidão, ainda é necessário um maior desenvolvimento da tecnologia PG, a fim de permitir uma utilização diária favorável dentro de um fluxo de trabalho simplificado. Como descrito por Forlani et al., a resolução do dispositivo de captura é capaz de influenciar a precisão desses sistemas, pelo que sensores e processadores aprimorados melhorarão a aquisição de imagem, fornecendo resultados mais precisos. Além disso, a integração da digitalização de tecidos moles no mesmo dispositivo eliminaria a necessidade de uma impressão adicional, reduzindo assim o erro e o tempo de trabalho. Por fim, uma redução no custo tornaria a tecnologia mais acessível aos médicos, permitindo também melhorias ao nível do software.

Dentro das limitações detetadas na presente revisão, foi possível constatar que a maioria dos estudos relatou que a PG mostrou uma precisão significativamente superior em impressões para reabilitação total com implantes, em comparação com IOS e CNV. A posição e o número de implantes e as angulações entre implantes não afetaram a precisão da tecnologia PG. No entanto, as distâncias entre implantes pareceram afetar a precisão. São necessários mais estudos clínicos para desenvolver a tecnologia e validar essas alegações, de preferência com amostras maiores e protocolos padronizados.

Palavras-chave: Implantes Dentários, Técnicas de Impressões Dentárias, Fotogrametria, Exatidão, Precisão, Veracidade.

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TABLE OF CONTENTS

LIST OF TABLES ...XI LIST OF FIGURES ... XII LIST OF ABBREVIATIONS ... XIII

1. INTRODUCTION... 1

2. MATERIALANDMETHODS ... 4

2.1. Objectives ... 4

2.2. Search Strategies ... 4

2.3. Eligibility Criteria ... 5

2.4. Study Selection ... 5

2.5. Quality Assessment & Risk of Bias ... 5

2.6. Data Extraction ... 6

2.7. Data Analysis and Synthesis ... 7

3. RESULTS ... 8

3.1. Literature Search ... 8

3.2. Description of the Studies ... 9

3.3. Interrater reliability and Quality assessment... 10

3.4. Outcomes Reported and Heterogeneity ... 11

3.4.1. 3D deviation ... 15

3.4.2. Linear and Angular Discrepancies ... 16

3.4.3. Inter-implant Distances (IID) and Angulations (IIA) ... 17

3.4.4. Implant position and number ... 18

3.4.5. Working Times, and Patient and Dentist Satisfaction ... 19

3.4.6. Clinical Assessment ... 19

4. DISCUSSION ... 20

4.1. Limitations of the Present Review ... 22

5. CONCLUSIONS ... 23

6. REFERENCES ... 24

7. SUPPLEMENTARYMATERIALS... 33

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LIST OF TABLES

Table 1. Summary of study designs of the ... 8

Table 2. Summary of the photogrammetry systems used. ... 8

Table 3. Summary of Implant systems used in the included studies... 8

Table 4. Summary of impression techniques used across the included studies. ... 8

Table 5. Data extracted from the included studies (in vitro). ... 12

Table 6. Data extracted from the included studies (in vivo)... 13

Table S1. Excluded articles with reasons ……….... 33

Table S2. Quantitative outcomes reported in the in vivo studies ………..……….. 34

Table S3. Quantitative outcomes reported in the in vitro studies ………..……….. 35

Table S4. Risk of bias assessment for the included in vitro articles ...………..……….. 37

Table S5. Quality assessment of the included case series ………... 37

Table S6. Quality assessment of the included case reports ……… 38

Table S7. Risk of bias assessment of the included non-randomized studies ……….………. 38

Table S8. Risk of bias assessment of the included RCTs ……….….….… 39

Table S9. Risk of bias assessment of the included diagnostic test study …………..……..… 39

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LIST OF FIGURES

Figure 1. Flow chart showing search process and screening based on PRISMA guidelines. ... 9 Figure S1. Interrater reliability analysis (k value, SPSS) – CRIS Guidelines ……….……... 40 Figure S2. Interrater reliability analysis (k value, SPSS) – JBI checklist case series …….… 40 Figure S3. Interrater reliability analysis (k value, SPSS) – JBI checklist case reports ..…… 41 Figure S4. Interrater reliability analysis (k value, SPSS) – ROBINS-I ..………. 41 Figure S5. Interrater reliability analysis (k value, SPSS) – RoB 2.0 ...……… 42 Figure S6. Interrater reliability analysis (k value, SPSS) – QUADAS-2 ………. 42

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LIST OF ABBREVIATIONS

3D Three-dimensional

ASA American Society of Anaesthesiologists (Physical Health Classification) CAD/CAM Computer-Aided Design/Computer-Assisted Manufacture

CMM Coordinate-Measuring Machine

CRIS Checklist for Reporting In Vitro Studies (guidelines) DSLR Digital Single-Lens Reflex (camera)

IOS Intraoral Scanner

IIA Inter-Implant Angulations IID Inter-Implant Distances

IPD Implant Prosthesis Dental 2004

ISO International Organization for Standardization JBI Joanna Briggs Institute

MeSH Medical Subject Headings MPI Medical Precise Implants

PG Photogrammetry

PIC Precise Implants Capture

PRISMA Preferred Reporting Items for Systematic Reviews and Meta-Analyses QUADAS Quality Assessment of Diagnostic Accuracy Studies

RCT Randomized Clinical Trial RoB Risk of Bias

ROBINS-I Risk Of Bias In Non-randomized Studies - of Interventions SD Standard Deviation

SPG Stereophotogrammetry TCP Top Center Points

º Degree(s) µm Micron/micra mm Millimeter(s)

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1. INTRODUCTION

The rehabilitation of edentulous patients with implant-supported fixed full-arch restorations has been reported to have a high long-term survival rate^1–5, with prosthodontic and implant survival rates ranging from 83 to 100%, and 91.3 to 100%, respectively.⁴ However, a high incidence of chipping in full arch rehabilitations has also been reported (34.8%).⁶ Concurrently, the demand for full arch implant rehabilitations has greatly increased over the years, as this treatment option can be considered the gold standard treatment for severe tooth loss. The high rate of technical complications has been associated with the absence of a passive fit between the implant and superstructure.⁷ On that regard, implant impressions are a critical step in implant dentistry, as they may introduce errors in the early stages of development of a rehabilitation, if done inaccurately. An imprecise transfer of an implant location can lead to an ill-fitting prosthesis, which may ultimately result in both biological and mechanical complications⁸, thus affecting the survival and longevity of the rehabilitation.

In 1995, Jemt and Lie⁹ defined passive fit as the level of accuracy that does not cause long-term complications, considering a maximum discrepancy of 150 µm as acceptable clinically, which the present review will also consider. Literature misfit limits varied between 10 and 150 and were obtained empirically.^10,11 Passive fit is dependent on different factors, but the most critical part is the accurate replication of the three-dimensional (3D) location of implants or abutments.¹² According to ISO 5725, accuracy is composed of trueness and precision. The first expresses how close the obtained measurements relate to the real arch measurements, and the second corresponds to the degree of similarity across obtained measurements of consecutive scans.¹³

A conventional workflow relies either on a closed- or open-tray impression, requiring materials like silicone or polyether to execute it.^14,15 For completely edentulous patients, splinted open-tray impressions are the most accurate within the conventional method, according to some authors.^15,16 Although it provides acceptable clinical results, it compiles several complex and time-consuming procedures, besides being less comfortable for the patient.^14,17 Also, the accuracy of definitive casts is influenced by multiple factors, such as impression materials¹⁸, matching tolerance of components¹⁹, and dimensional changes in the master cast.²⁰

Through the latest technological developments, accessibility to digital impression methods has increased in implant dentistry, and intraoral scanning (IOS) is now a widely used

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digital impression technique.²¹ Furthermore, when used with implant-supported single crowns and short-span restorations the accuracy of IOS has been recognized.^22–24 However, nowadays full-arch digital implant impressions taken with these systems are still not sufficiently accurate for clinical application, as a large portion of the literature agrees that conventional techniques perform better in these scenarios.^25–31 Factors like inter-implant distance, scan body type, intraoral scanner type, operator experience,mobility degree of soft tissues, ambient light, light reflection, saliva, steam, and the number and 3D position of the scan bodies can influence the overall accuracy of the IOS.^32,33

For that reason, a technology capable of registering implant positions with better accuracy, without being influenced by the prementioned factors is in need. In 1994, implant dentistry watched the introduction of photogrammetry technology to detect the marginal adaptation between the prosthesis and the implants. In 1999, Jemt et al.³⁴ reported that photogrammetry technology could successfully record the implant replica positions of an edentulous mandible cast. Photogrammetry has been defined by the American Society of Photogrammetry and Remote Sensing (ASPRS) as the art, science, and technology of obtaining reliable information about physical objects and the environment, through the process of recording, measuring, and interpreting imagery and digital representations of energy patterns derived from the non-contact sensor system.³⁵ It utilizes multiple reference points in photographs to make precise measurements, transforming that visual data into a list of coordinates.³⁵ Besides, this technology has been used by intraoral scanner manufacturers as a calibration protocol, given its superior level of accuracy.

Nowadays, some photogrammetric systems were designed and manufactured commercially for implant dentistry. PIC Camera^® (Precise Implants Capture Dental, Madrid, Spain) is a camera composed of two built-in charge-coupled devices (CCDs) and an infrared flash.³⁶ According to the manufacturer, this device can produce 150 frames/min with an error margin inferior to 10 µm.^37,38 The precision of this system relies on black flag-shaped plastic pieces with white dots precisely positioned that are fitted to each implant abutment. Another system commonly used in dental practice is the ICam4D^® (IMetric4D, Courgenay, Switzerland) which consists of a handheld device that comprises four cameras and one projector, and combines photogrammetric and structured light scanning techniques to capture 3D data. It also uses high-precision optical markers with a unique proprietary target arrangement, called ICamBodies, to determine the position and orientation of implants.

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Additionally, this system includes another component, ICamRefs, similar to healing abutments, making it simpler to take an impression of the soft tissues with an IOS. The software then allows the user to transform the ICamPositions into the coordinate system of the gingiva using the ICamRefs.³⁸

Thus, the aim of the present review was to compare the accuracy of three methods of impressions on implant-supported fixed full-arch rehabilitations: photogrammetry, conventional and intraoral digital scanning techniques.

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2. MATERIAL AND METHODS

This study followed the Preferred Reporting Items for Systematic Reviews and Meta- analysis (PRISMA) guidelines³⁹. Registry in the International Prospective Register of Ongoing Systematic Reviews (PROSPERO) was undertaken with the registration number CRD42022351669.

2.1. Objectives

The purpose of the present review was to evaluate the accuracy (linear and angular measurement deviations) of full arch rehabilitation implant impressions with photogrammetry equipment compared to intraoral scanners and conventional methods. The focused question was elaborated by using the PICO format (participants, interventions, comparisons, outcomes):

In full arch implant-supported rehabilitations, what are the differences in accuracy between photogrammetry, conventional and intraoral scanners methods?

2.2. Search Strategies

The review search was undertaken in four major databases (ScienceDirect, PubMed, Cochrane, and LILACS) until 8^th August 2022 with the following terms being used in the search strategies:

(((((((photogrammetry[MeSH Terms]) OR (photogrammetric[All Fields])) OR (stereophotogrammetric[All fields])) AND (dental implants[MeSH Terms])) OR (implants[All Fields])) OR ("implant position")) AND (dental impression technique[MeSH Terms])) OR ("impression[All Fields]) AND (accuracy[All Fields]).

The search spanned for 10 years, from January 2012 to August 2022 and the search strategy was adapted to each database. Also, on ScienceDirect database the filter ‘Research articles’ was selected.

A grey literature search was performed using Google Scholar, where

‘photogrammetry’, ‘dental impression technique’, and ‘dental implants’ were the keywords used. Only the first 300 results⁴⁰ were considered and Publish and Perish (Harzing.com) software was used to facilitate the collection of citations from multiple pages, oversee the number of citations per article, and export all the search citations. Additionally, a manual search of the reference list of the included studies was undertaken and the relevant reviews on the subject were also checked for possible additional records.

The citations from all the databases were then collected into a web-based screening software program (Rayyan QCRI; rayyan.qcri.org); for filtering and removal of duplicates, as

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well as making the first screening. Two of the reviewers (DB and DM) shared the library, including the study titles, abstracts, and, later, the uploaded full text, as needed.

2.3. Eligibility Criteria

The main inclusion criteria were considered as follows: (P) edentulous patients with full arch implant-supported rehabilitations as the treatment plan, or patients rehabilitated with this type of restorations, (I) studies using photogrammetry impressions of the implants/analogs as the intervention, (C) studies that compare photogrammetry technology with either conventional methods or intraoral scanning impressions, and (O) studies reporting on accuracy (precision and/or trueness) expressed as overall 3D deviation (mean difference; mean ± standard deviation, SD; or root mean square, RMS), angular or linear deviations, working time (min./sec.), dentist and/or patient satisfaction (visual analog score, VAS), or clinical assessment/follow-up duration. Articles such as Randomized clinical trials (RCTs), observational studies, prospective and retrospective studies, case reports, case series, and in vitro studies were considered; without language restrictions. Regarding exclusion criteria: short communications, letters to editors, patents, book chapters, reviews or systematic reviews, meta- analyses, articles without any outcomes, and articles published outside the time interval established were not considered; studies with zero implants placed (criterium a); only partial rehabilitation or single crowns (criterium b), or wrong intervention/technology (criterium c) were excluded. The records excluded during the full-text selection process are listed in Table S1, with the corresponding reasons and exclusion criteria.

2.4. Study Selection

The titles and abstracts of all records identified through the electronic searches were read independently and screened by two authors (DB and DM). For studies appearing to meet the inclusion criteria, or for which there were insufficient data in the title and abstract to make a clear decision, the full record was obtained. Records focused on subjects out of the scope of this review were excluded. Disagreements were resolved by discussion between the authors.

Any conflict regarding an article was resolved by discussion among the reviewers.

2.5. Quality Assessment & Risk of Bias

An assessment of study quality and risk of bias was performed by two researchers (DB and CM). The Joanna Briggs Institute (JBI) respective checklists⁴¹ were used to assess the quality of both case reports and case series. Case reports and case series were classified as

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‘concerning’ whenever an item from the respective checklists failed to be observed or was unclear. For all in vitro studies, the risk of bias was assessed recurring to an adaptation of the CRIS Guidelines⁴² according to the following parameters’ description: description of the sample size calculation (criterium A); meaningful difference between groups (criterium B);

description of the sample preparation and handling (criterium C); single-operator protocol implementation (criterium D); use of all materials according to the manufacturer’s instructions, and calibration (criterium E); allocation sequence, randomization, and blinding (criterium F);

and adequate statistical analysis (criterium G). If the authors reported the parameter, the study received a “Yes” for that specific parameter. In the case of missing information, the parameter received a “No”. The risk of bias was scored based on the sum of “Yes” answers received: 0 to 2 corresponding to a high bias, 3 to 5 to some concerns, and 6 to 7 indicating a low risk of bias.

Finally, for the RCTs included in the review, the Cochrane Risk of Bias (RoB) 2.0 Tool⁴³ was utilized; the ROBINS-I Tool⁴⁴ was used for the comparative clinical study, as it was a non- randomized clinical study; the QUADAS-2 tool⁴⁵ was considered for the only diagnostic test study considered. Any conflict was resolved through discussion. Cohen’s kappa (k) coefficient was used to evaluate the interrater agreement and calculated using a statistical software program (IBM SPSS Statistics v28.0 IBM Corp) with kappa values from 0 to 0.20 considered as having no level of agreement; 0.21 to 0.39 minimal agreement; 0.40 to 0.59 weak agreement;

0.60 to 0.79 moderate agreement; 0.80 to 0.90 strong agreement; and almost perfect agreement for values above 0.90.⁴⁶ Tables S4-S9 summarize the quality assessment process from both authors.

2.6. Data Extraction

Discussion about which data to extract took place, and multiple items were considered valid. The following data were retrieved from the studies: author, year of publication, title, study setting, design, arch included (maxillary, mandibular, or both), implant system(s) used, implant number and position, dental application, device used (stereophotogrammetric systems or DSRL cameras), comparator(s), reference element, evaluation method used, and outcomes reported. Contact with authors for providing missing data was performed. An online spreadsheet (Google Sheets; Google LLC, Mountain View, California, USA) was used to manage all the mentioned data. Qualitative outcomes were compiled in Tables 5 and 6, and quantitative outcomes were presented in Tables S2 and S3, when available. As some of the studies presented their results for individual distances and angles, only significantly different values were presented. Overall accuracy values are also presented in tables S2 and S3.

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2.7. Data Analysis and Synthesis

Both qualitative and quantitative synthesis of the included studies was done and complemented by summary tables. Results for accuracy were divided and presented in different groups: 3D deviation, for both precision and/or trueness, or overall accuracy; linear and angular discrepancies; inter-implant distances (IID) and angulations (IIA); implant position and number; working time and costs; and clinical assessment. Any quantitative data regarding 3D deviation was presented as RMS and the remaining outcomes as mean ± SD, or median values.

When median values were the results present, conversion to mean values was done. Individual local values were preferred to overall mean values when they offered more clear evidence of clinical relevance. All articles that reported on quantitative outcomes considered ⍺=0.05.

Meta-analysis will be performed if at least ten RCTs are included with a low risk of bias as advised by the literature to decrease the risk of cumulative error and false credibility.⁴⁷

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8

3. RESULTS

3.1. Literature Search

The study selection process is summarized in Figure 1. A total of 8293 papers were extracted from four online databases (1409 in PubMed, 6631 in ScienceDirect, 177 in Cochrane, and 77 in LILACS) and the first 300 results in Google Scholar considered. A total of 433 duplicated records were obtained after a manual revision of the screening software suggestions. Of the remaining 7860 articles, screening based on title and abstract resulted in the exclusion of 7829 records according to the inclusion criteria and the scope of the current systematic review. Regarding the full-text screening phase, 20 of the 31 articles left were eligible for the systematic review based on the inclusion criteria. Additionally, 1 more article was included from a manual search conducted in the references of included studies. Of the resulting 21 records, the greatest number of studies (8 studies) had been performed in 2021, and only two studies had been published yet in 2022. Simplified summaries of study designs, photogrammetric and implant systems used, and impression techniques are presented in Tables 1 to 4. All the data collected is presented in Tables 5 and 6, including authors, year of publication, study design, arch included, implant system, implant numbers, dental application, device used, reference element, comparator(s) selected, evaluation method and the main conclusions for each study.

Table 1. Summary of study designs of the included studies.

Study design Number of studies

Experimental (in vitro) 10

Case report 6

Non-randomized study 2

RCT pilot 1

Diagnostic test study 1

Case series 1

Table 2. Summary of the photogrammetry systems used.

Photogrammetric device Number of studies

PIC camera 13

DSRL camera 4

ICam (IMetric) 4

Table 3. Summary of implant systems used in the included studies.

Implant system In vitro studies

In vivo

studies Total

Straumann 5 3 8

Nobel Biocare 4 2 6

Zimmer 0 2 2

TiCare/Mozo-Grau 0 2 2

MPI, Avinent, Biomet 3i 0 1, each 3

IPD 2004 1 0 1

MPI, Medical Precise Implants; IPD, Implant Prosthesis Dental; NI, No information.

Table 4. Summary of impression techniques used across the included studies.

Technique used

Total of Impressions

In vitro

Total of Impressions

In vivo

Photogrammetry 117 66

Intraoral scanner 55 32

Conventional method (splinted open tray)

70 24

Total 242 122

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9

3.2. Description of the Studies

Tables 5 and 6 present detailed data of the included studies, the first regarding in vitro papers and the second with in vivo records. Ten in vitro studies were included, all with experimental design, in addition to 11 clinical articles: 1 RCT pilot, 6 case reports, 2 non- randomized clinical studies, 1 diagnostic test study, and 1 case series.

10 studies reported results on the maxillary arch (7 in vitro, and 3 in vivo), and 6 studies (3 in vitro, and 3 in vivo) used the mandibula. Both arches were used in 5 articles, all in vivo.

Different implant systems were observed in the selected records. Eight articles (5 in vitro, and 3 in vivo) used the Straumann^® system, and 6 studies (4 in vitro, and 2 in vivo) were performed in the Nobel Biocare^® implant system. Additionally, 2 in vivo studies selected Zimmer^® for the implant system, two used Ticare/Mozo-Grau, and one in vitro article used IPD 2004 system. MPI, Avinent, and Biomet 3i were all used in one in vivo article, each.

Figure 1. Flow chart showing search process and screening based on PRISMA guidelines.

Full-text articles excluded, with reasons

n=11

Studies included in qualitative review n=21

Full-text articles assessed for eligibility n=31

Records excluded (not related with review)

n=7829

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10

A total of 571 implants were placed, 407 within in vivo studies and 164 implant analogs for in vitro articles, where the number of implants/analogs placed varied between 3, 4^48,49, 5^50,51, 6^52–57, and 8⁵⁸, with their position being reproduced by a total of 364 impressions (PG:

183, IOS: 87, CNV: 94), when combining both type of study designs. One record failed to provide information regarding the number of implants placed, patients included, and impressions made with the reported device.⁵⁹ Nevertheless, the mentioned article was included as its data about time and costs could add value to the review.

All articles used photogrammetry as an implant transfer position tool. The most described photogrammetric system was the PIC camera (in both study settings), featured in 13 studies. In addition, four records resorted to ICam4D^® from IMetric to register the implant positions. Both devices are based on the use of infrared sensors and stereo cameras to record the implant 3D coordinates. Therefore, encoded optical markers attached to the implant fixtures or analogs were used as a reference in 17 articles, whenever one of these two systems was selected. A DSLR camera was operated in 4 in vitro articles, using optical targets^50,51, or predetermined marks^56,57 as reference elements, and varying from 12 to 16 images per impression.

A Coordinate Measuring Machine (CMM) was reported by 6 in vitro articles to deliver a reference set of data as a control. Two in vitro articles used geometric and mathematical tools to achieve superimposition of the implant abutments’ coordinates and resorted to a rototranslation method.^56,57Articles that reported on quantitative outcomes, opted to use 3D analysis and superimpositions through software and laboratory scanners to scan the master casts when a conventional method was used as comparator/control. Case reports and case series used clinical examination after intervention or clinical outcome at the established follow-up as the main evaluation method.

3.3. Interrater reliability and Quality assessment

The results of Cohen’s kappa interrater reliability for the individual questions of each assessment tool were as follows: JBI showed minimal agreement (k=0.370) between the authors for case reports’ checklist; JBI checklist for case series (k=constant), CRIS guidelines for in vitro studies (k=0.966), ROBINS-I (k=0.963); and QUADAS-2 (k=constant) all showed almost perfect agreement; RoB 2.0 showed moderate agreements (k=0.788). The k scores are presented in Figures S1-S6. Every in vitro study included in this review was classified as presenting ‘some concerns’ regarding the risk of bias, except for one⁵⁵, being classified as having a low risk of bias (Table S4). In most cases, the main issues in these publications were

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related to the absence of a sample size calculation (Criterium A) and/or allocation sequence, randomization, and blinding (Criterium F). No study was able to fulfill criterium F, and only two were able to do so with criterium A.^49,55

Within the in vivo articles, all case reports and case series were assessed using the respective JBI checklists. All six case reports were considered to have ‘concerning’ quality (Table S6). The included case series manuscript was also assessed as having ‘concerning’

quality (Table S5). Using the RoB 2.0 tool, the RCT pilot was considered to have ‘low risk of bias’, considering that the main outcomes were dentist and patient satisfaction (Table S8).

Using the ROBINS-I tool, also from Cochrane, one non-randomized study included was considered as having a ‘low risk’ of bias, and the other as having “serious” risk of bias (Table 7). Finally, the diagnostic test study was considered to have a ‘low risk’ of bias. (Table S9).

3.4. Outcomes Reported and Heterogeneity

All outcomes reported were presented with high heterogeneity when considering the measurements' effect. Results were conveyed with different outcomes: overall accuracy⁵⁸, general^52–55 and local trueness and precision⁴⁸, linear and angular deviation⁶⁰, root mean square of superimposition48,49,52,58, average errors^51,61, standard error of measurements⁵¹, and correlation coefficients, making it impossible to combine and run a meta-analysis. Although accuracy was the main objective of the included articles, the overall 3D deviation was not the most evaluated outcome among them. As such, the results were divided into multiple sections throughout the text, to showcase every outcome reported, related to the accuracy of the systems.

In virtue of the different evaluation methods used for the same outcome, detailed information for each study concerning these topics is despicted in Tables 5 and 6. Also, an

49,5848,49,60,61overview of the quantitative data obtained regarding 3D deviation and other outcomes is displayed in Tables S2 and S3.

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12 Table 5. Data extracted from the included studies (in vitro).

▴Quantitative data were reported in this study (see Table S3). PG, photogrammetry; IOS, intraoral scanner; CNV, conventional method; CMM, coordinate measuring machine; DSLR, digital single-lens reflex. *Two IOS devices were reported, the number corresponds to the addition of both devices.

Author(s), Year publ.

Study design

Arch included

Implant system

Implant analogs

Number of Impressions Device used

Reference element

Comparator(s) Evaluation method

Outcomes reported

PG IOS CNV

▴Ma B et al. 2021⁵²

Experimental Maxillary Straumann analog (RC Bone-Level)

6 10 10 10 ICam4D

(metric)

Encoded optical markers

IOS (TRIOS3);

CNV (splinted open tray)

CMM machine PG with the lowest 3D discrepancy (trueness+precision), IOS with the highest

▴Revilla- Léon M et al. 2021⁵⁴

Experimental Maxillary Straumann Analog (RC Screw-retained straight)

6 10 20* 10 ICam4D

(metric)

IOS 1 (TRIOS3);

IOS 2 (iTero Element);

CNV (splinted custom open tray)

CMM machine CNV with the lowest 3D discrepancy, and PG with the highest. IOS was reliable and had similar performance to CNV

▴Sallorenzo A et al. 2021⁵⁵

Experimental Maxillary IPD 2004 SL 6 10 10 - PIC

camera

IOS (TRIOS3) CMM machine PG delivered greater precision and trueness than IOS

▴Revilla- Léon M et al. 2021⁵³

Experimental Maxillary Straumann Analog (RC Screw-retained straight)

6 10 - 10 PIC

camera

CNV (splinted custom open stray)

CMM machine CNV significantly higher overall accuracy (precision & trueness). CNV with a uniform 3D discrepancy, PG with higher on one side and smaller on the contralateral side.

▴Tohme H et al. 2021⁴⁹

4 15 15 15 PIC

camera

IOS (TRIOS3);

Superimposition, 3D analysis

PG had more accuracy (trueness &

precision); Implant angulation did not affect precision but affected trueness.

▴Tohme H et al. 2021⁴⁸

4 15 - 15 PIC

camera

IOS (TRIOS3);

Superimposition, 3D analysis

PG had the lowest 3D discrepancy and global angular deviation (trueness &

precision). IOS with the highest trueness deviations but the same level of precision.

▴Bratos M et al. 2018⁵⁰

Experimental Mandibular RP Nobel Replace

10 18

(3x6)

- 5 DSLR

camera

Custom optical targets

CNV (splinted custom open tray)

CMM machine Precision was similar between PG and CNV; Lip retraction and mouth opening did not affect the accuracy of PG.

▴Rivara F et al. 2016⁵⁷

Experimental Mandibular NobelReplace (Nobel Biocare)

12 (6x2)

2 - - DSLR

camera

Predetermined marksts

None Rototranslation

method, geometric and mathematical tool, CMM machine

PG was reliable for analyzing a dimensional discrepancy between the pre-operative and post-operative implant positions.

▴Forlani G et al. 2014⁵⁶

Experimental Maxillary NobelReplace (Nobel Biocare)

105 22 - - DSLR

camera

Predetermined marksts

None Rototranslation

method, geometric and mathematical tool, Superimposition

Precise registration of the position and angulation of multiple implants.

▴Bergin J et al. 2013⁵¹

Experimental Mandibular RP Nobel Replace

5 5 - 5 DSLR

camera

Custom optical targets

CNV (modified splinted impression)

CMM machine Viable, accurate and easy technique for making multiple implant impressions.

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13 Table 6. Data extracted from the included studies (in vivo)

Authors, Year publ.

Study design Arch included

Implant system

Implants / patients

Number of Impressions Total (Maxillary/Mandibular)

Device used

PG IOS CNV

▴Yan Y et al. 2022⁵⁸

Non- randomized clinical trial

Both Straumann

(Bone-Level Tapered)

120 / 17 21 (12/9)

12 (6/6)

- ICam4D

(metric)

IOS (CS3600);

Superimposition 3D analysis, Sheffield test, clinical examination, and panoramic radiographs

PG accuracy was comparable to lab scanning and higher than IOS; and not affected by position/number of implants

▴Orejas- Pérez et al. 2022⁶¹

Diagnostic test study

Both MPI

External Hex

16 / 1 10 (5/5)

20*

(10/10)

- PIC

camera

IOS 1 (TRIOS3);

IOS 2 (True Definition)

Linear and angular meausrements, using Euclidean distances and angles.

PIC had the best precision;

not affected by IID or arch (mandibular/maxillary)

▴Zhang Y et al. 2021⁶⁰

Non- randomized clinical trial

Both Nobel Active (Nobel Biocare)

79 / 14 arches

14 (5/9)

- 14

(5/9)

ICam4D (metric)

Linear measurements (euclidean distances) and relative angulations, 3D analysis

ICam4D had clinically acceptable accuracy.

↑ deviations with ↑ IID.

Accuracy not affected by IIA or arch (maxilla/mandible).

Rico J et al. 2021⁶²

Case report Maxillary Avinent (Coral Interna)

6 / 1 1 - - PIC

camera

None Clinical outcome for 2 years.

PG achieved adequate esthetic and functional outcomes, with shorter working times.

Molinero- Mourelle P et al. 2019⁶³

Case report Maxillary Biomet 3i and Nobel Biocare AB

8 / 1 1 - - PIC

camera

None Clinical outcome for 6 months and 1 year

PIC is quick and more comfortable for patients.

Need for more studies.

Sanchéz- Monescillo A et al.

2019⁶⁴

Case report Mandibular Zimmer TSV (Zimmer Dental)

4 / 1 1 - - PIC

camera

None Screw fit test and radiographs

Reliable technique with adequate fit

Suaréz M et al. 2018⁶⁵

Case report Mandibular Zimmer TSV (Zimmer Dental)

4 / 1 1 - - PIC

camera

None Clinical outcome for 1 and 2 years

PG provides an accurate technique for obtaining passive framework fit

Peñarrocha- Oltra D et al. 2017⁶⁶

Case report Maxillary Ticare/

Mozo-Grau Osseous

8 / 1 1 - - PIC

camera

None Sheffield test and screw resistance test

Passive fit by both tests

▴Quantitative data were reported in this study (see Table S2). RCT, randomized controlled trial; PG, photogrammetry; IOS, intraoral scanner; CNV, conventional method; NR, Not reported. NC, Not clear. IID, inter- implant distance; IIA, inter-implant angulation; MPI, Medical Precision Implants. *Two IOS devices were reported, the number corresponds to the addition of both devices.

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14 Table 6. (continued)

Authors, Year publ.

Study design

Arch included

Implant system

Implants / patients (n)

Number of Impressions Total (Maxillary/mandibular)

Device used

PG IOS CNV

▴Peñarrocha- Diago M et al.

2017⁶⁷

RCT pilot

Both Ticare / Mozo-Grau InHex

131 / 18 11 (7/4)

- 10

(8/2)

PIC camera

Sheffield test, finger pressure and periapical radiograph, clinical outcome for 1 year

PG with shorter time needed, and greater dentist and patient satisfaction. No differences in implant survival, MBL, or prosthesis survival.

Sánchez- Monescillo A et al. 2016³⁶

Case report

Mandibular Straumann (Bone-Level Tapered)

7 / 1 1 - - PIC

camera

None Clinical and

radiographic outcomes for 1 year

The PG method suggests certain advantages over conventional methods. More studies are needed.

Pradíes G et al. 2014⁶⁸

Case series

Both Straumann

(Soft tissue level), Zimmer

24 / 3 4 (1/3)

- - PIC

camera

None Clinical outcome for 1 and 2 years

Optimal fit, precise, rapid, convenient for dentist and the patient.

▴Quantitative data were reported in this study (see Table S2). RCT, randomized controlled trial; CNV, conventional method; NR, Not reported; IDD, inter-implant distance. *Two IOS devices were reported, the number corresponds to the addition of both devices.