Etiopathogenesis of Dental Caries

Abstract

Dental caries, as a pervasive and complex global health issue affecting individuals of all ages, is influenced by a multitude of factors. These factors encompass the interplay of demineralization and remineralization processes, dietary and oral hygiene practices, salivary composition and flow, tooth morphology, genetics, fluoride exposure, and environmental and socioeconomic variables. This chapter analyzes three categories of factors that cause dental caries, such as: general, local, and iatrogenic factors. Initially, the genetic predisposition, gender-related hormonal fluctuations, aging, immunological elements, pregnancy-related changes, chronic diseases, hormonal disorders, vitamin levels, and socioeconomic factors are included in general factors that contribute to the susceptibility to dental caries. Moreover, to understand and mitigate caries risk, it is pivotal to analyze local factors such as dental morphology, oral hygiene, and the vital role of saliva. Additionally, premature loss of primary teeth, crowding, orthodontic treatment, dental fillings, and prosthetic dental work can lead to iatrogenic issues affecting oral health. Recognizing the multifaceted nature of dental caries, susceptibility underscores the necessity for comprehensive strategies in oral health care. Therefore, this chapter underlines that proper oral care, preventive measures, and meticulous attention during dental procedures are paramount for maintaining optimal oral health.

1. Introduction

Tooth decay, commonly known as dental caries, is a widespread chronic disease affecting people of all ages and demographics. Often seen as just a minor discomfort, it significantly impacts not only dental health but also overall well-being and quality of life [1]. Dental caries arises from a complex mix of genetic, environmental, behavioral, and iatrogenic factors, illustrating its multifaceted origins.

The development and progression of dental caries are influenced by various factors, which this chapter categorizes into general, local, and iatrogenic. General factors include heredity, gender, age, immunological factors, hormones, vitamins, and diet, each playing a unique role in an individual’s vulnerability to tooth decay [2, 3, 4]. These elements underscore the importance of understanding the interaction between internal physiological processes and external environmental conditions. Factors like genetic predispositions, hormonal changes, and dietary choices work together, influencing both the risk and the actual development of dental caries [5, 6].

Local factors, such as dental morphology, oral hygiene, and saliva, are also crucial in caries development, highlighting the significance of physical characteristics and personal habits. The structure and alignment of teeth and the composition and flow of saliva greatly affect the likelihood of developing caries [7, 8]. Additionally, iatrogenic factors, which are unintended consequences of medical or dental treatments, can also contribute to the development of caries [9].

This chapter aims to offer a comprehensive perspective on the various factors influencing dental caries, enhancing understanding of the complexities in its prevention and management. It emphasizes the need for personalized dental care approaches, tailored to each individual’s unique risk factors and dental characteristics [10]. The chapter also acknowledges the ongoing need for research and innovation in dental science to develop more effective strategies for preventing and treating dental caries.

Addressing dental caries effectively requires a thorough understanding of its etiology and a comprehensive approach to intervention. This overview aims to provide dental professionals with fundamental insights for designing effective, personalized prevention and treatment strategies. We explore the diverse aspects of dental caries as we delve into the complexities of this common yet intricate condition.

In summary, we examine the most important factors of tooth decay. A.D.A. (American Dental Association) makes the classification of direct and indirect factors of caries presentation. Our classification will be according to F.D.I. (International Dental Federation), according to which the division is made into three categories thoroughly presented and described in this chapter:

The research methodology applied in this chapter, which primarily relies on a literature review, is the systematic review [11] and meta-analysis [12] approach. This methodology is particularly suited for synthesizing a wide range of research findings from various studies to provide a comprehensive understanding of a complex subject like dental caries. This systematic review and meta-analysis approach provides a structured and comprehensive way to analyze the existing literature on dental caries, ensuring that the conclusions drawn are based on a thorough and unbiased evaluation of current research.

2. General factors

Six general factors are presented in this chapter including: heredity, gender, age, imunological factor, hormones, and vitamins and food.

2.1 Heredity

By heredity we mean that one family has a predisposition for the appearance of caries compared to the other. In contrast to it, there are families where the caries percentage coefficient is much smaller, which is justified by genetic factors [13].

Genes play a role in dental caries development, but the condition’s origin is influenced by a complex interplay of environmental and genetic factors. To validate these findings across diverse populations, further research is needed. Identifying genetic risk factors is essential for screening susceptible individuals and deepening our understanding of gene involvement in caries development. Insights from these studies offer valuable tools for efficiently implementing advanced preventive measures, diagnostics, and innovative therapies in managing the disease [14].

Differences in the oral microbiome arise from a combination of genetic and peripheral factors. In the symbiotic relationship between microorganisms and the host, homeostasis in the oral microbiome is typically maintained. However, certain conditions may shift this balance toward a parasitic relationship, leading to the proliferation of cariogenic microorganisms and the development of dental caries. Advanced molecular biology techniques have enabled the discovery of new species of cariogenic microorganisms. It’s important to note that each person’s oral microbiome is unique, making commonly adopted disease prevention measures not universally applicable to all individuals [15].

Host genetics stands out as a pivotal factor contributing to variations in susceptibility to caries among individuals. Numerous genes influence an individual’s likelihood of developing caries by playing crucial roles in immune response, saliva production, and tooth enamel development. On a global scale, scientists are engaged in genetic studies to explore various diseases, including dental caries [16, 17]. Experimental studies have revealed a genetic impact on caries outcomes, distinguishing between susceptible and resistant strains [18].

Studies indicate that specific genes influence enamel resistance, while another set affects salivary composition and the host’s response to infection. Furthermore, numerous linkages and association studies have identified genomic regions and polymorphisms associated with dental caries. This extensive research underscores the multifaceted genetic factors contributing to variations in caries susceptibility [14, 19, 20].

Caries risk and resistance are influenced by a multitude of genetic factors encompassing taste preference, salivary attributes, immune response, tooth morphology, enamel composition and structure, and behavioral traits. Unlike Mendelian inheritance, where a single gene may have a major effect, dental caries, being a chronic and complex disease, is likely influenced by the interplay of multiple genes. Additionally, gene-gene interactions or gene-environment interactions may give rise to epigenetic effects, further contributing to the intricate balance between risk and resistance associated with dental caries. The holistic understanding of these diverse genetic factors highlights the complexity of the genetic landscape influencing susceptibility to and protection against dental caries [7, 8].

2.2 Gender

Gender inequalities in dental health, particularly in terms of caries and periodontal diseases among adults, have been extensively studied [21, 22, 23]. Numerous findings indicate that women tend to experience a higher burden of dental caries, possibly due to hormonal changes leading to increased viscosity and reduced saliva production. The average pH of women’s saliva is lower than that of men, 7.2 and 7.5, respectively [13]. Studies consistently show that females, across different age groups, are at a higher risk of and experience more carious lesions than males. Several factors contribute to this discrepancy, such as earlier tooth eruption in girls, variations in dietary behaviors, access to oral health care, hormonal differences, and characteristics of dentition, tooth enamel, or saliva.

Additionally, gender may influence oral health habits, with men often neglecting their oral health and displaying poorer habits. Research indicates that women generally perceive oral health as having a greater impact on quality of life, associating poor oral health with pain and embarrassment. Furthermore, studies reveal that women tend to have better oral health literacy and more positive attitudes toward dental visits compared to men [24, 25, 26, 27, 28, 29].

2.3 Age

Tooth decay is more a disease of young people. Some periods of life are distinguished by a higher index of caries appearance.

The age of 5 to 8 years is characterized by a higher percentage of caries, and then it rapidly declines with the eruption of permanent teeth. The period of adolescence (13–20 years old) is again considered as a period with more caries, which is followed by stabilization until the age of 40–50 years, where caries is combined with periodontopathy [13].

Aging is a natural physiological process characterized by changes over time, occurring at varying rates influenced by lifestyle, environment, and genetics. Distinguishing between normal aging and disease can be challenging. In the oral cavity, aging is marked by enamel wear, chipping, fracture lines, and a darker tooth color. Deposition of secondary dentin reduces the size of pulp chambers and canals. Coronal or root caries, however, signifies disease.

Limited periodontal attachment loss is associated with aging, often seen as recession on the buccal surface. Severe periodontitis peaks at 35–40 years, affecting 10.5–12% of the population. Mucosal tissue changes with age, including reduced wound-healing capacity. Smoking significantly increases the risk of mucosal pathology. Reduced salivary gland function is linked to medication usage and disorders like diabetes, more prevalent in older adults [30].

Masticatory function is crucial for older adults, promoting a nutritionally complete diet to prevent sarcopenia and frailty syndrome. Successful oral aging is defined by adequate function and comfort, with a proposal for 20 functional teeth in occlusion as a measure. Healthy oral aging contributes to overall healthy aging, encompassing both biological and social well-being.

2.4 Imunological factor

The likelihood of developing tooth decay in individuals is influenced by various factors, including the immune system and the oral microbiome. The oral microbiome, in turn, is shaped by both environmental and genetic determinants. These interrelated elements contribute to the complex dynamics of oral health, highlighting the importance of understanding how genetic and environmental factors interact to impact an individual’s susceptibility to tooth decay [15].

Recent research shows that the appearance of caries is directly dependent on the presence of secretory immunoglobulin IgA in saliva. The amount of IgA less than 14.2 mg/100 ml in saliva enables the rapid development of Streptococus mutans, one of the most dangerous causes for the appearance of caries [13].

Antibodies against oral bacteria, including Streptococus mutans, can be identified in both human serum and saliva. Numerous studies comparing caries experience and the levels of immunoglobulin or specific antibodies have been conducted to explore the potential role of these antibodies in natural caries immunity. However, a consistent pattern in the results of such experiments is not evident. Several small-scale human trials in adults have demonstrated the feasibility of elevating levels of salivary S-IgA antibodies against Streptococus mutans. In some instances, these antibodies were shown to interfere with the colonization of Streptococus mutans [31].

Chronic diseases - patients suffering from chronic diseases have a higher prevalence of caries. Patients with myocardial infarction, diabetes mellitus, or duodenal ulcer present differently in the oral cavity due to medications, ketonic bodies (change in the pH of saliva), and fetor ex ore. All these are predisposing factors for the development of microorganisms and the greater appearance of caries [13].

Poor oral health is associated with an increased likelihood of developing respiratory and cardiovascular diseases, adverse pregnancy outcomes, and diabetes mellitus. The role of oral microorganisms in the etiology and progression of these conditions is becoming increasingly recognized. Current knowledge on oral dysbiosis sheds light on the pathophysiologic mechanisms involving oral microorganisms in each of these health issues [32].

Within oral pathology, various diseases such as dental caries, periodontal diseases, endodontic infections, and even oral cancer have been linked to oral microorganisms. Beyond oral health, systemic diseases like nonoral infections, adverse pregnancy outcomes, cardiovascular diseases, and diabetes are prevalent pathologies with established connections to microorganisms in the oral cavity. Understanding these associations is crucial for comprehensive healthcare management and preventive measures [33].

2.5 Hormones and vitamins

Any hormone disorder manifested in the form of hyperfunction or hypofunction of the thymus, pituitary, thyroid, and parathyroid as a consequence causes the appearance of caries in a larger percentage [13].

The oral health needs of women and men exhibit significant differences, with hormonal fluctuations playing a substantial role in influencing oral health at various life stages, including puberty, menses, pregnancy, and menopause [34].

Menopause, a natural physiological process typically occurring around the fifth decade of a woman‘s life, marks the end of the fertile phase. During menopause, women undergo biological and endocrine changes, particularly in sex steroid hormone production, which can impact overall health [35].

The presence of estrogen receptors in the oral mucosa makes the oral cavity susceptible to direct effects from variations in hormone levels. Peri- and postmenopausal women commonly experience oral symptoms such as xerostomia, a sensation of painful mouth with numerous potential causes, and burning mouth syndrome. Understanding and addressing these oral health issues specific to women are crucial for providing comprehensive and tailored healthcare [36].

Hypovitaminosis of vitamins A, D, and C is the cause of tooth decay. Vitamin A plays a special role during the development of the dental organ and the periodontium. The lack of vitamin D manifests itself with more caries, as the calcification phase of the tooth is disturbed. Vitamin C played a special role during the development of connective tissue and collagen in the first phase of dental organ formation [13].

Calcium serves as a crucial component of the body’s skeleton, and its adequate supply in the diet is essential, particularly in the context of reduced endogenous synthesis. This becomes especially important in cases of endocrine problems to support the maintenance of healthy bones and teeth [37, 38]. The body’s regulation of calcium metabolism is orchestrated by vitamin D, which exerts its influence on the gastrointestinal tract, kidneys, and skeleton.

Vitamin D, a lipophilic steroid hormone, plays a significant role in oral health by acting as an anti-inflammatory agent, stimulating the production of anti-microbial peptides [39, 40]. The term “vitamin D” refers to a group of fat-soluble biomolecules synthesized in the skin through exposure to ultraviolet irradiation from the sun. Apart from its role in oral health, vitamin D is also closely associated with bone metabolism and skeletal integrity [41].

2.6 Food

Dental caries is a dynamic process characterized by the interaction of susceptible tooth surfaces; cariogenic bacteria, primarily Streptococcus mutans; and a fermentable carbohydrate source. Among dietary sugars, sucrose is the most common and is considered the most cariogenic carbohydrate. The risk of developing dental caries is heightened with frequent consumption of carbohydrates, especially in the form of simple sugars [42].

Dental caries is a multifactorial disease heavily influenced by behavioral factors, with oral hygiene, fluoride use, and dietary habits playing crucial roles [43]. Excessive consumption of fermentable carbohydrates has been identified as a primary driver, impacting the integrity of teeth as well as the pH of plaque and biofilm [44]. Beyond the quantity of carbohydrates, the frequency of carbohydrate intake is also considered a significant factor in the risk of developing dental caries [45]. Recent research has revealed positive associations between the frequency of sugar consumption and the incidence of caries, observed in both adults and children [46, 47].

Dental caries occurs when the demineralization of the enamel surpasses its demineralization capacity [42]. Bacteria present in dental plaque metabolize fermentable carbohydrates, especially sucrose, from the diet. This metabolic activity produces organic acids, leading to a decrease in pH. It is hypothesized that when the pH falls below 5.5, demineralization of the enamel occurs—a threshold known as the critical pH. This demineralization process occurs each time fermentable carbohydrates are consumed.

3. Local factors

3.1 Dental morphology

The concept of dental morphology involves the study of teeth in terms of their size, shape, and arrangement within the oral cavity. Klein and Palmer initially described the connection between dental caries and different morphological types of teeth [48]. Some characteristics of dental morphology predispose teeth to dental decay. Presently, it is recognized that most dental caries are confined to specific sites. Here are some crucial reasons for this:

3.1.1 Tooth shape and size

Molars and premolars are more susceptible to decay than other teeth due to their complex surfaces and grooves (fissures). These grooves can be deep and narrow, making it challenging for toothbrush bristles to clean effectively, leading to an accumulation of plaque and food particles, thus increasing decay risk. Mandibular molars are significantly more prone to caries than other teeth. It appears that irregularities on the occlusal surface facilitate the development of biofilm, eventually leading to carious lesions [49].

Teeth that are smaller than average may have larger gaps between them, trapping food and debris more easily, thus leading to plaque formation and an increased risk of dental caries, particularly when oral hygiene is poor. Teeth that are larger or shaped in a way that causes uneven distribution of biting forces can suffer from excessive wear. This can lead to the breakdown of enamel over time, making the teeth more susceptible to decay. Some individuals are born with congenitally misshaped teeth, or they may develop teeth of altered size due to factors like grinding (bruxism). These conditions affect the effectiveness of cleaning teeth and protecting them from decay.

3.1.2 Spacing and alignment

When teeth are crowded or misaligned, they form tight spaces that are challenging to clean properly. This difficulty can lead to plaque buildup, increasing the likelihood of cavities developing between the teeth (known as interproximal decay).

When teeth aren’t properly aligned, they can wear unevenly. This misalignment can create specific niches and crannies where plaque—a sticky mix of food particles, bacteria, and saliva—tends to accumulate. If not removed in time, plaque hardens into tartar, which is much tougher to get rid of.

Misaligned teeth can also cause gum problems. Gums may not fit securely around misaligned teeth, creating pockets where bacteria can grow. This can lead to gingivitis (gum inflammation) and, if left untreated, more severe periodontal disease, which is a risk factor for tooth decay. Improper alignment can lead to abnormal wear of tooth enamel. This wear can weaken teeth and make them more susceptible to decay [50].

The gaps between teeth can trap tiny food particles, creating an ideal environment for bacteria that produce acids. These acids can erode tooth enamel, leading to cavities. For those undergoing orthodontic treatment, braces, or other appliances can make it harder to clean teeth effectively, increasing the risk of decay if proper oral hygiene is not maintained. Sometimes it is very difficult for clinicians to visualize proximal lesions during clinical exam. It is estimated that at least 40% of proximal carious lesions are missed during dental examinations [51].

Overall, while misalignment or spacing issues do not directly cause tooth decay, they create conditions that can increase the risk of decay if proper dental hygiene is not practiced.

3.1.3 Enamel structure and thickness

Variations in the thickness and quality of enamel can influence decay risk. Thinner and weaker enamel provides less protection against bacteria and acids, increasing the likelihood of tooth decay. Enamel is made up of tightly bunched, oblong crystals called crystallites, which are significantly smaller than the width of a human hair. These crystallites have a core-shell structure, where the core is more soluble than the shell. This difference in solubility can contribute to the enamel’s vulnerability to decay. The core of the crystallites contains higher concentrations of impurity atoms such as magnesium, sodium, carbonate, and fluoride. These impurities, while contributing to enamel’s strength, also make it more soluble, which can be a factor in tooth decay. This core-shell structure is vital for understanding the enamel’s resistance and susceptibility to decay at a microscopic level [52].

Enamel thickness varies across different teeth and even within a single tooth, often being thickest at the cusp and thinnest at the borders. The thickness of enamel can be an important factor in its ability to resist decay. Thicker enamel might provide more resistance against the acidic environment in the mouth that leads to decay, whereas thinner enamel might be more susceptible to decay [52].

The atomic structure of enamel, particularly the core surrounded by shell crystallites, highlights specific areas within the teeth more prone to decay. Understanding these structures on an atomic level can lead to improved strategies for strengthening teeth against decay and repairing erosion damage. Furthermore, the distribution of minor components within the enamel crystallites, particularly the impurities at the core, offers insights into potential preventive measures against dental caries.

These discoveries open the door to new dental treatments and interventions. For example, they might lead to the development of materials or techniques that strengthen the enamel’s crystalline structure or protect its more vulnerable parts. The research into the atomic structure and composition of tooth enamel provides a much deeper understanding of its vulnerabilities and strengths, which is crucial for developing more effective ways to combat tooth decay [52].

3.2 Oral hygiene

Oral hygiene, or rather the absence of it, can greatly contribute to tooth decay. There are a number of ways poor oral hygiene can lead to this common dental issue – tooth decay.

Dental plaque is a clear, sticky film that forms on your teeth when they are not properly cleaned of sugars and starches. Bacteria feed on these substances, creating plaque. If not regularly brushed and flossed away, plaque can build up, particularly in hard-to-reach spots [53]. In addition, if not removed, plaque can harden into tartar, which is difficult to clean and acts as a shield for bacteria. The bacteria in plaque produce acids that attack tooth enamel, leading to decay and gum disease [54]. The acids produced by bacteria in plaque lead to the demineralization of the tooth’s enamel, creating tiny openings or holes—the first stage of cavities. Once the enamel is eroded, these acids can reach the dentin layer, which is softer and less resistant to acid [52].

Fluoride helps strengthen tooth enamel and can even reverse early signs of tooth decay. Not using fluoride-containing toothpaste or not getting enough fluoride from other sources leads to inadequate flouoride exposure, which can make teeth more susceptible to decay [55]. Also, poor oral hygiene can lead to gum disease (gingivitis), which can progress to a more serious form called periodontitis. This condition can expose the roots of your teeth to plaque and increase your risk of tooth decay [56].

Without regular brushing and flossing, food particles can remain in a mouth, providing a food source for bacteria. The longer these particles stay in a mouth, the more time bacteria have to produce acids that can cause decay [57]. Saliva helps wash away food particles and neutralize acids produced by bacteria. Therefore, poor oral hygiene can contribute to dry mouth conditions, which can exacerbate the risk of tooth decay.

3.3 Saliva

Saliva is protective to the oral hard and soft tissues since it supports the clearance of food debris and sugar, as well as contributes to the aggregation and elimination of microorganisms, thereby demonstrating a buffering capacity to neutralize acid components and promoting the remineralization of tooth enamel among other antimicrobial properties [58]. For example, many associations have been found between dental caries and salivary composition [58]. Such salivary properties may be used as biomarkers for the risk of future disease and could potentially inform interventions targeted at that risk [58, 59].

Dental caries is a highly prevalent microbial chronic dental disease that affects a greater percentage of the world’s populations [60]. Dental caries is a sugar-driven biofilm-mediated oral disease characterized by the phasic demineralization and remineralization of the hard tissues of the tooth, besides being multifactoria [61]. The saliva encasing the soft and hard tissues of the craniofacial region contains some organic and inorganic components, which play a significant role in caries in the host, hence their critical role as biomarkers in the diagnosis of caries [62]. In simpler terms, dental caries occurs due to the imbalance of cariogenic microorganisms within the oral biofilm, which triggers the fermentation of available dietary carbohydrates into fermentative acids [63]. This process causes a loss of minerals in the dental hard tissues, eventually destroying tooth structure [63]. The way diet, host susceptibility, and microorganisms interact is a significant determinant of how dental caries will develop in an individual [64]. Considering that the teeth are continuously bathed in saliva, the salivary components undoubtedly play a fundamental role both in the initiation and progression of dental caries and are considered a major biomarker for the diagnosis and detection of caries.

The proteins in saliva are essential not only to maintain the integrity of the tooth but also to protect against dental caries due to various mechanisms [60]; for instance, they reduce or inhibit demineralization at the surfaces of the teeth that are exposed to this process. They are needed in the creation of a film called the acquired enamel pellicle, which provides continuous protection of the teeth from attrition and softening, as well as attracting calcium ions for the reorganization of the enamel. Nonetheless, the defense of the oral cavity also attributes to salivary proteins, including lactoferrin, proline-rich proteins, carbonic anhydrase, immunoglobulins, and mucins, which are the most common, representing about 20 to 30% of the salivary proteins [65].

4. Iatrogenic factors

Iatrogenic factors that cause tooth decay refer to dental decay that occurs as a result of medical or dental treatment. These factors are often unintentional and can arise from various dental procedures or treatments. Some common iatrogenic factors that can contribute to tooth decay are further explored and presented.

4.1 Restorative dental work

Restorative dental work, while crucial for repairing and maintaining dental health, can sometimes contribute to tooth decay if not executed or maintained properly. Sometimes, dental restorations like fillings or crowns may not fit perfectly, creating small gaps where food particles and bacteria can accumulate, leading to decay. Over time, these restorations can also wear down or break, allowing decay to develop underneath them. Restorations with margins (edges) that extend below the gum line can be challenging to clean and may irritate the surrounding gum tissue. This can lead to periodontal problems and potentially increase the risk of decay, especially at the root surfaces of teeth [66].

Dental restoration materials can degrade or wear down over time. This breakdown can lead to gaps or rough surfaces where bacteria can accumulate, increasing the risk of decay. If oral hygiene is not maintained after restorative procedures, the risk of tooth decay can increase, particularly around the restoration sites.

4.2 Orthodontic appliances

Braces and other orthodontic appliances can make it difficult to maintain good oral hygiene, as food particles and plaque may accumulate around brackets and wires. Plaque is a sticky film of bacteria and food particles, and it is the primary cause of tooth decay. The complex structure of orthodontic appliances makes it more challenging to clean all areas of the teeth and gums effectively. Braces can make it harder to brush and floss effectively. This difficulty in maintaining oral hygiene can lead to a build-up of plaque and tartar, increasing the risk of tooth decay [67].

Orthodontic appliances can trap food particles, providing a constant source of nutrients for bacteria in the mouth. These bacteria produce acids that can erode tooth enamel and lead to cavities. The prolonged presence of plaque on tooth surfaces can lead to demineralization of the enamel, which is the first step in the formation of cavities. This is often seen as white spots on the teeth after braces are removed. Some orthodontic treatments or appliances might affect saliva flow in the mouth. Saliva plays a crucial role in neutralizing acids and washing away food particles, so a reduction can increase the risk of decay.

To mitigate these risks, it’s important for individuals with orthodontic appliances to maintain diligent oral hygiene. This includes brushing after every meal, using a fluoride toothpaste, flossing daily (using tools like floss threaders or water flossers), and regular visits to the dentist for cleanings and check-ups. Additionally, minimizing the intake of sugary foods and drinks can reduce the risk of decay [67].

4.3 Fluoride overuse

Excessive fluoride, particularly during early childhood when teeth are developing, can lead to a condition called dental fluorosis. This condition is characterized by changes in the appearance of the tooth enamel, ranging from mild (white streaks) to severe (brown stains, pitting). Dental fluorosis occurs when children consume too much fluoride over a prolonged period. It’s essential to use fluoride cautiously, especially with young children. They should be taught to spit out toothpaste and not swallow it. The use of fluoride mouth rinses is not recommended for children under 6 years old. In general, fluorosis is preventable by moderating fluoride intake and ensuring proper use of fluoride-containing dental products [68].

4.4 Medications affecting saliva production

Certain medications prescribed for unrelated medical conditions can reduce saliva flow, leading to dry mouth or xerostomia [69, 70, 71]. Medications that can reduce saliva production are:

• Antihistamines: often used for allergies, they can decrease saliva flow.

• Antidepressants: some types of antidepressants can have a drying effect on the mouth.

• Antihypertensives: used to treat high blood pressure, these can also reduce saliva production.

• Diuretics: prescribed for conditions like hypertension and some kidney disorders, diuretics can decrease saliva by increasing urine production.

• Chemotherapy drugs: used in cancer treatment, some of them can affect saliva glands.

Saliva is crucial for neutralizing acids in the mouth and washing away food particles, so a reduction in saliva can increase the risk of decay [69, 70, 71].

4.5 Inadequate dental sealants or fluoride treatments

If dental sealants, which are meant to protect the grooves and pits in the chewing surfaces of teeth, are not applied properly or completely, they can leave parts of the tooth surface exposed to plaque and decay. Fluoride treatments help strengthen enamel and make it more resistant to acid attacks from bacteria. Inadequate application, poor quality, or insufficient frequency of fluoride treatments can reduce their effectiveness, leaving teeth more vulnerable to decay. It’s important to ensure that sealants and fluoride treatments are applied correctly and monitored regularly for maintenance, to maximize their protective benefits against tooth decay [72].

4.6 Poor infection control

Inadequate infection control during dental procedures can lead to bacterial contamination and subsequent tooth decay. Infection control is crucial in dental clinics to prevent the spread of infectious diseases among patients and healthcare workers. This includes proper sterilization of dental instruments, use of personal protective equipment, and adherence to hygiene protocols. While lapses in these practices do not cause cavities, they can increase the risk of transmitting bacterial, viral, or fungal infections, which could complicate overall oral health and treatment outcomes [73].

5. Conclusions

The extensive exploration of factors influencing dental caries reveals a multifaceted and intricate nature of this dental issue. The discussion spanned various dimensions, including general factors like heredity, gender, age, immunological factors, hormones, vitamins, and diet, all contributing uniquely to the susceptibility and manifestation of dental caries.

General factors like genetics, hormonal changes, and dietary habits underscore the complexity of caries, highlighting the interplay of internal and external influences. Hereditary factors point to a genetic predisposition, while gender-related aspects, such as hormonal fluctuations in women, add another layer to the risk of caries. Age-related changes in dental structures and the immune system further accentuate the variability of caries occurrence among different age groups.

Local factors, particularly dental morphology, emphasize the significance of physical attributes of teeth in caries development. Variations in tooth shape, size, and enamel structure can increase the risk of decay, underscoring the importance of individualized dental care. Misalignments and spacing issues, although not direct causes of decay, create conditions conducive to bacterial growth and acid production, thereby increasing decay risk.

Oral hygiene practices play a pivotal role in preventing or accelerating caries development. Poor oral hygiene leads to plaque and tartar buildup, gum diseases, and enamel demineralization, which are primary contributors to tooth decay. Saliva, a key element in oral health, aids in neutralizing acids and preventing caries, with its composition and flow rate being critical in maintaining oral health.

Iatrogenic factors remind us that medical and dental interventions, though necessary, can sometimes inadvertently contribute to caries. Dental restorations, orthodontic appliances, and fluoride treatments, if not properly managed, can lead to conditions favorable for caries development.

This comprehensive analysis of caries etiology suggests that effective prevention and management strategies should be holistic, considering the interplay of genetic, environmental, behavioral, and clinical factors. It highlights the need for personalized dental care approaches, tailored to individual risk factors and specific dental characteristics. Moreover, it underscores the importance of continuous research and innovation in dental sciences to develop more effective preventive and therapeutic strategies against dental caries.

In summary, the fight against dental caries requires a multifaceted approach, integrating knowledge from various disciplines and considering the unique circumstances of each individual. This holistic understanding is crucial in developing more effective, personalized strategies for the prevention and treatment of this prevalent dental issue.