#!/usr/bin/env python3
"""Generate a 50-mark elaborate essay PDF on Critical Appraisal of Metallic and
Non-Metallic Inlays and Onlays."""

from reportlab.lib.pagesizes import A4
from reportlab.lib.units import cm
from reportlab.lib import colors
from reportlab.platypus import (
    SimpleDocTemplate, Paragraph, Spacer, Table, TableStyle,
    ListFlowable, ListItem, PageBreak
)
from reportlab.lib.styles import getSampleStyleSheet, ParagraphStyle
from reportlab.lib.enums import TA_CENTER, TA_JUSTIFY

OUT = "/tmp/workspace/inlay-onlay-essay/output/Critical_Appraisal_Inlays_Onlays.pdf"

styles = getSampleStyleSheet()
styles.add(ParagraphStyle(name="TitleBig", fontSize=20, leading=24, alignment=TA_CENTER,
                           spaceAfter=6, fontName="Helvetica-Bold"))
styles.add(ParagraphStyle(name="SubTitle", fontSize=12, leading=16, alignment=TA_CENTER,
                           spaceAfter=18, fontName="Helvetica-Oblique", textColor=colors.HexColor("#444444")))
styles.add(ParagraphStyle(name="H1", fontSize=15, leading=18, spaceBefore=16, spaceAfter=8,
                           fontName="Helvetica-Bold", textColor=colors.HexColor("#1a3d6d")))
styles.add(ParagraphStyle(name="H2", fontSize=12.5, leading=15, spaceBefore=10, spaceAfter=6,
                           fontName="Helvetica-Bold", textColor=colors.HexColor("#2a5a8a")))
styles.add(ParagraphStyle(name="Body", fontSize=10.7, leading=15.5, alignment=TA_JUSTIFY,
                           spaceAfter=8, fontName="Helvetica"))
styles.add(ParagraphStyle(name="BodyBold", parent=styles["Body"], fontName="Helvetica-Bold"))
styles.add(ParagraphStyle(name="Bullet", parent=styles["Body"], leftIndent=14, spaceAfter=3))
styles.add(ParagraphStyle(name="TableCell", fontSize=9, leading=11.5, fontName="Helvetica"))
styles.add(ParagraphStyle(name="TableHeader", fontSize=9.3, leading=12, fontName="Helvetica-Bold",
                           textColor=colors.white))

def P(text, style="Body"):
    return Paragraph(text, styles[style])

def bullets(items, style="Bullet"):
    return ListFlowable(
        [ListItem(P(i, style), leftIndent=10, value="•") for i in items],
        bulletType="bullet", start="•", leftIndent=12, spaceBefore=2, spaceAfter=8
    )

def make_table(header, rows, col_widths):
    data = [[Paragraph(h, styles["TableHeader"]) for h in header]]
    for r in rows:
        data.append([Paragraph(str(c), styles["TableCell"]) for c in r])
    t = Table(data, colWidths=col_widths, repeatRows=1)
    t.setStyle(TableStyle([
        ("BACKGROUND", (0, 0), (-1, 0), colors.HexColor("#1a3d6d")),
        ("GRID", (0, 0), (-1, -1), 0.5, colors.HexColor("#999999")),
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        ("ROWBACKGROUNDS", (0, 1), (-1, -1), [colors.white, colors.HexColor("#eef2f8")]),
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        ("LEFTPADDING", (0, 0), (-1, -1), 5),
        ("RIGHTPADDING", (0, 0), (-1, -1), 5),
    ]))
    return t

story = []

# ---------- Title Page ----------
story.append(Spacer(1, 3*cm))
story.append(P("CRITICAL APPRAISAL OF METALLIC AND<br/>NON-METALLIC INLAYS AND ONLAYS", "TitleBig"))
story.append(P("An Elaborate Essay - Conservative Dentistry &amp; Restorative Prosthodontics (50 Marks)", "SubTitle"))
story.append(Spacer(1, 1.5*cm))
story.append(P(
    "Inlays and onlays occupy the middle ground of restorative dentistry, bridging the gap between "
    "simple direct plastic restorations and full-coverage crowns. The choice of restorative material - "
    "metallic (cast gold and base-metal alloys) versus non-metallic (composite resin, ceramic, and "
    "CAD/CAM-milled materials) - profoundly influences the biomechanical performance, esthetic outcome, "
    "biological compatibility, longevity and cost of the restoration. This essay critically appraises both "
    "categories across their indications, contraindications, laboratory and clinical properties, advantages, "
    "disadvantages, and long-term evidence, so as to guide rational material selection in contemporary practice.",
    "Body"
))
story.append(PageBreak())

# ---------- 1. Introduction ----------
story.append(P("1. INTRODUCTION", "H1"))
story.append(P(
    "An <b>inlay</b> is an intracoronal indirect restoration that is fabricated outside the mouth (extraorally) "
    "and cemented into a prepared cavity, restoring the restoration within the confines of the cusps without "
    "covering them. An <b>onlay</b> is an extension of the inlay concept that additionally covers one or more "
    "cusps or the entire occlusal surface, thereby providing cuspal protection while still being more "
    "conservative than a full crown. Both are classified as indirect restorations because they are constructed "
    "on a cast or a digital model and later luted to tooth structure with a cement or resin adhesive, in "
    "contrast to direct restorations (amalgam, direct composite) that are placed and set inside the mouth in a "
    "single visit.", "Body"))
story.append(P(
    "Historically, inlays and onlays were almost exclusively fabricated from cast gold alloys because of their "
    "unmatched combination of marginal adaptability, wear compatibility with enamel, and longevity. With the "
    "advent of acid-etch bonding, improved composite resins, pressed and milled ceramics, and CAD/CAM "
    "technology, non-metallic tooth-colored alternatives have become the restorations of choice for most "
    "patients who prioritize esthetics. A critical appraisal therefore requires comparing both material classes "
    "on scientific and clinical merit rather than on popularity alone.", "Body"))

story.append(P("1.1 Classification of Inlays and Onlays", "H2"))
story.append(bullets([
    "<b>Based on material:</b> Metallic (Type II/III/IV gold alloys, base-metal alloys - Ni-Cr, Co-Cr) and "
    "Non-metallic (direct/indirect composite resin, feldspathic porcelain, leucite-reinforced ceramic, lithium "
    "disilicate, zirconia-reinforced lithium silicate, resin nanoceramic/hybrid ceramic, CAD/CAM composite blocks).",
    "<b>Based on extent:</b> Simple inlay (intracoronal only), onlay (cuspal coverage), high-strength/reinforced "
    "onlay, and overlay/table-top onlay (full occlusal coverage without axial reduction).",
    "<b>Based on fabrication technique:</b> Direct (fabricated intraorally, e.g., direct composite inlay), "
    "Indirect conventional (wax pattern - casting; or laboratory-processed composite/porcelain), and "
    "CAD/CAM (optical scan - digital design - milling or 3D printing).",
]))

# ---------- 2. Metallic ----------
story.append(P("2. METALLIC INLAYS AND ONLAYS", "H1"))
story.append(P(
    "Cast gold alloys remain the historical gold standard (literally) for posterior indirect restorations. "
    "Alloys used range from Type I (soft, for low-stress inlays) to Type IV (hard, for onlays and long-span "
    "restorations), along with base-metal alloys such as nickel-chromium and cobalt-chromium used in patients "
    "with cost constraints or specific clinical needs.", "Body"))

story.append(P("2.1 Properties Relevant to Clinical Performance", "H2"))
story.append(bullets([
    "<b>Marginal integrity:</b> Gold can be burnished, allowing the thin margins to be physically adapted to "
    "the cavosurface, producing the closest marginal seal of any restorative material.",
    "<b>Wear behavior:</b> The wear rate of gold alloy is very close to that of natural enamel, so it does not "
    "excessively abrade the opposing dentition, unlike some ceramics.",
    "<b>Mechanical strength:</b> High tensile and compressive strength, excellent fatigue resistance, and "
    "ductility allow thin restorations in areas of high occlusal load without fracture.",
    "<b>Biocompatibility:</b> High-noble gold alloys are chemically inert and extremely well tolerated by "
    "gingival and pulpal tissues; base-metal alloys carry a risk of nickel hypersensitivity.",
    "<b>Retention/resistance form:</b> Because of its strength, less axial taper and cavity depth are required "
    "compared to ceramic, permitting more conservative tooth preparation in certain situations (though margins "
    "still need adequate reduction for structural integrity).",
    "<b>Corrosion resistance:</b> Noble alloys resist tarnish and corrosion in the oral environment; base-metal "
    "alloys are more prone to corrosion products and ion release.",
]))

story.append(P("2.2 Indications", "H2"))
story.append(bullets([
    "Posterior teeth subjected to heavy occlusal loads (bruxism, clenching) where esthetics is a secondary concern.",
    "Long-span or large restorations replacing multiple cusps where fracture resistance is critical.",
    "Patients with a history of ceramic/composite restoration failure or high caries/wear risk.",
    "Situations demanding minimal-to-no tooth reduction at margins (feather-edge finish possible with gold).",
]))

story.append(P("2.3 Contraindications and Disadvantages", "H2"))
story.append(bullets([
    "<b>Esthetics:</b> The single greatest limitation - unacceptable in the esthetic zone and increasingly "
    "rejected by patients even in posterior teeth.",
    "<b>Cost:</b> High material cost (noble metal content) and laboratory/technician charges.",
    "<b>Technique and time:</b> Requires two or more appointments, precise impression making, die fabrication, "
    "wax pattern, casting, finishing and polishing - a resource- and time-intensive laboratory workflow.",
    "<b>Thermal conductivity:</b> High thermal conductivity can cause pulpal sensitivity if an adequate "
    "insulating base/liner is not placed, especially with deep preparations.",
    "<b>Galvanism:</b> Risk of galvanic current/metallic taste when dissimilar metallic restorations contact "
    "in the same arch.",
    "<b>Bonding limitation:</b> Conventional cast alloys are cemented rather than adhesively bonded (unless "
    "surface treatments/silane-coupled base metal are used), so retention relies more on geometric form than "
    "chemical adhesion, limiting reinforcement of remaining tooth structure.",
    "<b>Biocompatibility concerns with base-metal alloys:</b> nickel sensitization, beryllium toxicity in older "
    "alloys, and higher corrosion potential.",
]))

story.append(P("2.4 Critical Appraisal", "H2"))
story.append(P(
    "Cast gold alloy inlays/onlays possess the best long-term clinical longevity data of any indirect "
    "restoration, with multiple long-term follow-up studies reporting survival rates exceeding 90% at 10 years "
    "and many restorations surviving 20-30 years with minimal marginal deterioration. Their major limitation is "
    "purely esthetic, and secondarily economic and technique-related. In an era where patients demand "
    "tooth-colored restorations, gold's clinical superiority is frequently outweighed by patient preference, "
    "relegating it to a shrinking (though evidence-strong) niche indication - particularly molars, patients with "
    "parafunction, and situations of restricted vertical space where a thin but strong restoration is required.",
    "Body"))

# ---------- 3. Non-metallic ----------
story.append(P("3. NON-METALLIC INLAYS AND ONLAYS", "H1"))
story.append(P(
    "Non-metallic restorations are now the dominant choice in contemporary indirect dentistry because they "
    "combine adhesive bonding with tooth-like esthetics. They fall into two broad subgroups: resin-based "
    "(composite) and ceramic-based materials.", "Body"))

story.append(P("3.1 Composite Resin Inlays/Onlays", "H2"))
story.append(bullets([
    "<b>Direct composite inlay:</b> Fabricated intraorally on the prepared tooth or on a die, then bonded "
    "in the same visit.",
    "<b>Indirect/laboratory composite:</b> Fabricated on a model with additional heat, light, or "
    "pressure-and-heat post-curing, which improves the degree of conversion, reduces polymerization shrinkage "
    "stress, and increases wear resistance and strength compared to direct composite.",
    "<b>CAD/CAM composite (resin nanoceramic) blocks:</b> Milled from industrially pre-polymerized blocks with "
    "highly uniform, void-free microstructure (e.g., resin nanoceramic materials), giving superior mechanical "
    "consistency."
]))
story.append(P("Advantages of Composite Inlays/Onlays:", "BodyBold"))
story.append(bullets([
    "Excellent, tooth-matching esthetics with good polishability.",
    "Adhesive bonding reinforces the remaining tooth structure and reduces cuspal flexure (the restoration "
    "acts to 'glue' the tooth back together).",
    "Modulus of elasticity closer to dentin than ceramic, so composite is more forgiving on the opposing "
    "enamel (less wear of antagonist tooth) and is easily repairable intraorally if chipped.",
    "Lower cost than ceramic/gold; can be milled chairside for same-day delivery.",
    "Conservative preparation with rounded internal angles, since bonding (not retention form) provides "
    "resistance.",
]))
story.append(P("Disadvantages of Composite Inlays/Onlays:", "BodyBold"))
story.append(bullets([
    "Lower wear resistance and fracture toughness than ceramic; more prone to surface staining and gradual "
    "loss of anatomic form/polish over time.",
    "Polymerization shrinkage and associated stress at the cement interface (mitigated, but not eliminated, "
    "by indirect fabrication).",
    "Technique-sensitive bonding protocol; moisture contamination compromises the adhesive interface.",
    "Long-term color stability inferior to ceramic, particularly with staining beverages/tobacco.",
]))

story.append(P("3.2 Ceramic Inlays/Onlays", "H2"))
story.append(bullets([
    "<b>Feldspathic/leucite-reinforced porcelain:</b> Excellent esthetics and translucency but relatively low "
    "flexural strength (~120-160 MPa); best suited to low-stress-bearing, adhesively-bonded situations.",
    "<b>Lithium disilicate glass-ceramic:</b> High flexural strength (~360-400 MPa after crystallization), "
    "excellent esthetics, available as pressed ingots or CAD/CAM blocks; currently the most widely used "
    "ceramic for posterior inlays/onlays.",
    "<b>Zirconia-reinforced lithium silicate / polycrystalline zirconia:</b> Very high strength, used for "
    "high-load onlays, though monolithic zirconia has lower translucency.",
    "<b>Resin-matrix (hybrid) ceramics:</b> A compromise class combining ceramic filler with a resin matrix, "
    "offering shock absorption and easier milling/repair.",
]))
story.append(P("Advantages of Ceramic Inlays/Onlays:", "BodyBold"))
story.append(bullets([
    "Superior, long-term color stability and translucency - the best esthetic match to natural enamel.",
    "High compressive strength and excellent wear resistance when properly polished and glazed.",
    "Chemically inert, highly biocompatible, and does not corrode.",
    "Strong adhesive bond achievable via hydrofluoric acid etching + silane coupling (glass-ceramics), "
    "reinforcing remaining tooth structure similar to composite.",
    "CAD/CAM workflow (e.g., chairside milling systems) allows same-day, single-visit fabrication, reducing "
    "provisionalization needs.",
]))
story.append(P("Disadvantages of Ceramic Inlays/Onlays:", "BodyBold"))
story.append(bullets([
    "Brittle - susceptible to catastrophic (non-repairable) fracture under tensile/flexural stress, especially "
    "if minimum thickness recommendations (commonly 1.0-1.5 mm occlusal / 1.0 mm axial, material-dependent) "
    "are not respected.",
    "Requires more tooth reduction than metal or composite to provide adequate bulk for strength, making the "
    "preparation less conservative in some designs.",
    "Higher wear on opposing natural enamel if the ceramic surface is inadequately polished/glazed or becomes "
    "roughened by adjustment (a well-documented antagonist-wear controversy versus composite/gold).",
    "Technique-sensitive cementation (etching, silanation, isolation) and higher laboratory/chairside milling cost.",
    "Difficult and unreliable intraoral repair if fractured; usually requires remake.",
]))

# ---------- 4. Comparative Table ----------
story.append(PageBreak())
story.append(P("4. COMPARATIVE CRITICAL APPRAISAL", "H1"))
story.append(P(
    "The table below synthesizes the key clinically relevant parameters across the major inlay/onlay material "
    "categories to allow direct, evidence-based comparison.", "Body"))

header = ["Parameter", "Cast Gold Alloy", "Base-Metal Alloy", "Composite Resin", "Ceramic (Glass/Lithium Disilicate)"]
rows = [
    ["Esthetics", "Poor (metallic)", "Poor (metallic)", "Good-Very good", "Excellent"],
    ["Fracture toughness", "Excellent (ductile)", "Good", "Moderate", "Low-Moderate (brittle)"],
    ["Wear resistance", "Excellent, enamel-friendly", "Excellent, harder than enamel", "Moderate", "Excellent (if polished)"],
    ["Wear of opposing enamel", "Minimal", "Can be high", "Low", "Variable/can be high if rough"],
    ["Marginal adaptation", "Excellent (burnishable)", "Good", "Good (bonded)", "Good (bonded, technique dependent)"],
    ["Bond to tooth structure", "Cementation only (mechanical)", "Cementation only", "True adhesive bond", "True adhesive bond (etched)"],
    ["Reinforcement of tooth", "Minimal", "Minimal", "Good", "Good"],
    ["Biocompatibility", "Excellent (noble)", "Variable (Ni sensitivity risk)", "Good", "Excellent (inert)"],
    ["Thermal conductivity", "High (needs liner)", "High", "Low (insulating)", "Low (insulating)"],
    ["Tooth reduction needed", "Minimal-moderate", "Minimal-moderate", "Conservative", "Moderate (bulk for strength)"],
    ["Repairability if fractured/chipped", "Not typically needed", "Not typically needed", "Easy, intraoral", "Difficult, usually remake"],
    ["Chairside/CAD-CAM same-day option", "No", "No", "Yes", "Yes"],
    ["Relative cost", "High", "Moderate", "Low-Moderate", "Moderate-High"],
    ["Long-term survival evidence (>10 yr)", "Very strong, >90%", "Strong", "Moderate, improving with indirect/CAD-CAM", "Strong, improving with lithium disilicate"],
]
story.append(make_table(header, rows, [3.6*cm, 3.2*cm, 3.2*cm, 3.0*cm, 3.4*cm]))
story.append(Spacer(1, 10))

# ---------- 5. Clinical decision-making ----------
story.append(P("5. FACTORS GOVERNING CLINICAL MATERIAL SELECTION", "H1"))
story.append(bullets([
    "<b>Esthetic demand and location:</b> Anterior/premolar visible zones strongly favor ceramic or composite; "
    "posterior molars in low-esthetic-demand patients may still justify gold.",
    "<b>Occlusal load and parafunction:</b> Heavy bruxers may fare better with gold or high-strength lithium "
    "disilicate/zirconia-reinforced ceramic rather than feldspathic porcelain or composite.",
    "<b>Remaining tooth structure:</b> Extensively broken-down teeth benefit from the adhesive reinforcement of "
    "bonded composite/ceramic onlays, which act to splint cusps together, versus non-bonded metal.",
    "<b>Available interocclusal space:</b> Limited vertical space (e.g., over-erupted opposing tooth) may "
    "necessitate the thinner cross-section achievable with metal, since ceramic requires greater bulk for "
    "strength.",
    "<b>Opposing dentition:</b> Natural, unrestored opposing enamel is best preserved by gold or well-glazed "
    "ceramic/composite; rough or under-glazed ceramic can accelerate antagonist wear.",
    "<b>Cost and number of visits:</b> Direct/CAD-CAM composite or chairside-milled ceramic reduce visits and "
    "cost versus a conventional cast/laboratory ceramic workflow.",
    "<b>Patient factors:</b> Known metal (nickel) allergy rules out base-metal alloys; bruxism, poor oral "
    "hygiene, or high caries risk affect long-term prognosis of any bonded restoration.",
])) 

story.append(P("6. LIMITATIONS COMMON TO BOTH CATEGORIES", "H1"))
story.append(bullets([
    "Both require at least a two-step clinical/laboratory process (except single-visit CAD/CAM), with an "
    "interim/temporary restoration phase that carries its own risk of leakage or dislodgement.",
    "Both are technique-sensitive at cementation - moisture control, cement selection, and complete removal of "
    "excess cement are critical for pulpal and periodontal health regardless of material.",
    "Secondary caries can occur at the margins of any indirect restoration if isolation, impression accuracy, "
    "or marginal fit is compromised.",
    "All indirect restorations require additional tooth reduction compared to a simple direct filling, and none "
    "are indicated in extremely small or minimally invasive cavities where a direct restoration suffices.",
]))

# ---------- 7. Conclusion ----------
story.append(P("7. CONCLUSION", "H1"))
story.append(P(
    "Neither metallic nor non-metallic inlays and onlays can be labelled unconditionally superior; each "
    "material class has a well-defined envelope of clinical strength. Cast gold alloy remains the benchmark "
    "for marginal precision, wear compatibility, and documented longevity, but its clinical use is constrained "
    "almost entirely by esthetic unacceptability and cost in modern practice. Non-metallic restorations - "
    "particularly adhesively bonded composite resin and high-strength glass-ceramics such as lithium "
    "disilicate - have largely supplanted metal because they combine acceptable-to-excellent mechanical "
    "performance with esthetics and true adhesive reinforcement of remaining tooth structure, while allowing "
    "efficient single-visit CAD/CAM delivery. A critical, evidence-based appraisal therefore favors "
    "individualized material selection: gold alloy for heavy-load, low-esthetic-demand posterior situations "
    "and lithium disilicate/composite (increasingly CAD/CAM-fabricated) for the great majority of contemporary "
    "esthetic posterior indirect restorations, always tailored to the patient's occlusal risk, remaining tooth "
    "structure, esthetic expectations, and financial considerations.", "Body"))

story.append(Spacer(1, 10))
story.append(P(
    "<i>Prepared as an academic essay for examination purposes (Conservative Dentistry &amp; Endodontics / "
    "Prosthodontics). Sources synthesized from standard restorative dentistry principles and current clinical "
    "literature on indirect restorative materials.</i>", "Body"))

doc = SimpleDocTemplate(OUT, pagesize=A4,
                         leftMargin=2*cm, rightMargin=2*cm, topMargin=1.8*cm, bottomMargin=1.8*cm,
                         title="Critical Appraisal of Metallic and Non-Metallic Inlays and Onlays")
doc.build(story)
print("PDF written to", OUT)

Successfully replaced 1 instance(s) of the string in '/tmp/workspace/inlay-onlay-essay/build_pdf.py'

Successfully replaced 1 instance(s) of the string in '/tmp/workspace/inlay-onlay-essay/build_pdf.py'